[Federal Register: October 5, 2007 (Volume 72, Number 193)]
[Proposed Rules]
[Page 56947-56972]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05oc07-24]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 91
[Docket No. FAA-2007-29305; Notice No. 07-15]
RIN 2120-AI92
Automatic Dependent Surveillance--Broadcast (ADS-B) Out
Performance Requirements To Support Air Traffic Control (ATC) Service
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This notice proposes performance requirements for certain
avionics equipment on aircraft operating in specified classes of
airspace within the United States National Airspace System. The
proposed rule would facilitate the use of Automatic Dependent
Surveillance-Broadcast (ADS-B) for aircraft surveillance by Federal
Aviation Administration and Department of Defense air traffic
controllers to accommodate the expected increase in demand for air
transportation. In addition to accommodating the anticipated increase
in operations, this proposal, if adopted, would provide aircraft
operators with a platform for additional flight applications and
services.
DATES: Send your comments on or before January 3, 2008.
ADDRESSES: You may send comments identified by Docket Number FAA-2007-
29305 using any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov
and follow the online instructions for sending your
comments electronically.
Mail: Send comments to the Docket Management Facility;
U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West
Building Ground
[[Page 56948]]
Floor, Room W12-140, Washington, DC 20590-0001.
Hand Delivery or Courier: Bring comments to the Docket
Management Facility in Room W12-140 of the West Building Ground Floor
at 1200 New Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5
p.m., Monday through Friday, except Federal holidays.
Fax: Fax comments to the Docket Management Facility at
202-493-2251.
Privacy Act: We will post all comments we receive, without change,
to http://www.regulations.gov, including any personal information you
provide. Anyone is able to search the electronic form of all comments
received into any of our dockets by the name of the individual
submitting the comment (or signing the comment, if submitted on behalf
of an association, business, labor union, etc.). You may review DOT's
complete Privacy Act Statement in the Federal Register published on
April 11, 2000 (65 FR 19477-78) or you may visit http://DocketInfo.dot.gov
.
Docket: To read background documents or comments received, go to
http://www.regulations.gov at any time and follow the online
instructions for accessing the docket. Or, go to the Docket Management
Facility in Room W12-140 of the West Building Ground Floor at 1200 New
Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
FOR FURTHER INFORMATION CONTACT: Vincent Capezzuto, Surveillance and
Broadcast Services Office, Air Traffic Organization, Federal Aviation
Administration, 800 Independence Avenue SW., Washington, DC 20591;
telephone 202-385-8288.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites interested persons to participate in this
rulemaking proposal by submitting written comments, data, or views. We
also invite comments relating to the economic, environmental, energy,
or federalism impacts that might result from adopting the proposals in
this document. The most helpful comments reference a specific portion
of the proposal, explain the reason for any recommended change, include
specific rule language changes, and include supporting data. We ask
that you send us two copies of written comments.
We will file in the docket all comments we receive, as well as a
report summarizing each substantive public contact with FAA personnel
concerning this proposed rulemaking.
Before acting on this proposal, we will consider all comments we
receive on or before the closing date for comments. We will consider
comments filed after the comment period has closed if it is possible to
do so without incurring expense or delay. We may change this proposal
in light of the comments we receive.
If you want the FAA to acknowledge receipt of your comments on this
proposal, include with your comments a pre-addressed, stamped postcard
on which the docket number appears. We will stamp the date on the
postcard and mail it to you.
Proprietary or Confidential Business Information
Do not file in the docket information that you consider to be
proprietary or confidential business information. Send or deliver this
information directly to the person identified in the FOR FURTHER
INFORMATION CONTACT section of this document. You must mark the
information that you consider proprietary or confidential. If you send
the information on a disk or CD-ROM, mark the outside of the disk or
CD-ROM and also identify electronically within the disk or CD-ROM the
specific information that is proprietary or confidential.
Under 14 CFR 11.35(b), when we are aware of proprietary information
filed with a comment, we do not place it in the docket. We hold it in a
separate file to which the public does not have access, and place a
note in the docket that we have received it. If we receive a request to
examine or copy this information, we treat it as any other request
under the Freedom of Information Act (5 U.S.C. 552). We process such a
request under the DOT procedures found in 49 CFR part 7.
Availability of Rulemaking Documents
You can get an electronic copy of rulemaking documents using the
Internet by--
1. Searching the Federal eRulemaking Portal (http://www.regulations.gov
);
2. Visiting the FAA's Regulations and Policies Web page at http://www.faa.gov/regulations_policies/
; or
3. Accessing the Government Printing Office's Web page at http://www.gpoaccess.gov/fr/index.html
.
You can also get a copy by sending a request to the Federal
Aviation Administration, Office of Rulemaking, ARM-1, 800 Independence
Avenue, SW., Washington, DC 20591, or by calling (202) 267-9680. Make
sure to identify the docket number, notice number, or amendment number
of this rulemaking.
Authority for This Rulemaking
The FAA's authority to issue rules regarding aviation safety is
found in Title 49 of the United States Code. Subtitle I, Section 106
describes the authority of the FAA Administrator. Subtitle VII,
Aviation Programs, describes in more detail the scope of the agency's
authority.
This rulemaking is promulgated under the authority described in
Subtitle VII, Part A, Subpart I, Section 40103, Sovereignty and use of
airspace, and Subpart III, section 44701, General requirements. Under
section 40103, the FAA is charged with prescribing regulations on the
flight of aircraft, including regulations on safe altitudes,
navigating, protecting, and identifying aircraft, and the safe and
efficient use of the navigable airspace. Under section 44701, the FAA
is charged with promoting safe flight of civil aircraft in air commerce
by prescribing regulations for practices, methods, and procedures the
Administrator finds necessary for safety in air commerce.
This proposal is within the scope of sections 40103 and 44701 since
it proposes aircraft performance requirements that would meet advanced
surveillance needs to accommodate the projected increase in operations
within the National Airspace System (NAS). As more aircraft operate
within the U.S. airspace, improved surveillance performance is
necessary to continue to balance the growth in air transportation with
the agency's mandate for a safe and efficient air transportation
system.
Table of Contents
I. Background
A. Vision of the Future
B. The Century of Aviation Reauthorization Act and NextGen
C. Today's Radar Environment
II. The ADS-B System
A. General
B. Ground Infrastructure
III. Summary of the Proposal
IV. The Proposal for ADS-B Out
A. Advantages of ADS-B Out
B. Avionics
1. 1090ES and UAT Broadcast Links
2. Broadcast Link Requirements for Different Flight Levels
3. Part 91 Appendix H Message Elements
4. Navigation Position Sensor and the Accuracy and Integrity of
the ADS-B Message
5. ADS-B Antenna Diversity and Transmit Power Requirements
6. Latency of the ADS-B Out Broadcast Message Elements
7. Maintenance
C. Operational Procedures
1. Applicability
2. Airspace
3. Pilot Procedures
4. Backup Surveillance Strategy
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5. Compliance Schedule for ADS-B Out Requirements
V. ADS-B In
A. Avionics
B. Applications and Services
VI. FAA Experience with ADS-B
A. Capstone
B. Gulf of Mexico
C. UPS--Louisville
D. Surveillance in Non-Radar Airspace
VII. ADS-B in Other Countries
VIII. Alternatives to ADS-B
IX. Rulemaking Notices and Analyses
I. Background
A. Vision of the Future
The demand for air travel is growing in the U.S. and around the
world. The FAA's forecasts project a doubling in U.S. airline passenger
traffic by 2025. The forecasts also show strong growth for general
aviation, especially with the advent of very light jets. By the end of
this decade as many as 400-500 of these small jets could join the fleet
each year. With the new small jets and other growth, the active general
aviation fleet is projected to grow from 230,000 aircraft today to
275,000 aircraft in 2020.
That is the demand from piloted aircraft. The development and use
of unmanned aircraft systems (UAS) is one of the next big steps forward
in aviation's evolution. The FAA is working across government and
industry to ensure the safe authorization of these aircraft to fly in
civil airspace.
The good news is U.S. air travel and related use of the National
Airspace System (NAS) will grow. That growth will bring challenges
since the present U.S. air traffic system--the world's largest and
safest--is not designed to absorb this level of growth. Today's system
is limited by outmoded technology--such as the constraints ground-based
radar places on the distance aircraft must be separated and the limits
caused by having to transmit information by voice between aircraft and
the ground.
The solution to managing the anticipated growth in the use of the
NAS is the Next Generation Air Transportation System, or NextGen, which
will assure the safe and efficient movement of people and goods as
demand increases. NextGen will use technology to allow precise
navigation, permit accurate real-time communication, and vastly improve
situational awareness. The goal: A system flexible enough to
accommodate safely whatever number, type and mix of aircraft there will
be in U.S. skies by 2025.
NextGen will be an aircraft-centric system with performance-based
requirements. The future system will describe performance for
navigation, communications, and surveillance.
For navigation, the aviation community is already seeing the
benefits of performance-based navigation with the use of Required
Navigation Performance (RNP) as well as Area Navigation (RNAV)
procedures at many U.S. airports. RNP and RNAV are examples of
procedures that use improved navigational accuracy as compared to
traditional procedures. The new procedures are being implemented
consistent with the ``Roadmap for Performance-Based Navigation.'' The
benefit of performance-based navigation: Enabling aircraft to fly
precisely defined flight paths with unprecedented accuracy.
For communication, NextGen will be built on a more comprehensive
and capable information network than has been previously available. It
will ensure the right information gets to the right person at the right
time. With performance-based navigation and internet-like access to
critical information--including nearly real-time weather--pilots will
be able to make precision landings at airports that have no control
towers, radar, or Instrument Landing Systems. Attaining the goal of
performance-based communications will depend on technology, such as
datalink, which would transmit key instructions directly to aircraft
flight management systems, which would speed receipt of critical
information and prevent errors that can come from manual data entry.
The third element--performance-based surveillance--relies on
technology that permits knowing the exact location of other aircraft in
the air and of other aircraft and ground vehicles on the airport
surface. The aviation community's experience with ADS-B, which
periodically broadcasts an aircraft's location--both horizontal and
vertical position and horizontal and vertical velocity--will lead
directly to the performance requirements. When displayed in the
cockpit, information obtained through ADS-B greatly improves
situational awareness in the en route segment, in the terminal area
during approaches, and on the airport surface. For additional
information on ADS-B activities, see Section VI, FAA Experience with
ADS-B later in the preamble.
This rulemaking is important because ADS-B is an essential NextGen
building block. Improving surveillance requires advanced onboard
equipment with backup capability. Most, if not all, of the surveillance
capability as well as the navigation and communications capabilities
should be onboard the aircraft so the required capabilities will go
wherever the aircraft goes. As part of the rulemaking effort, the FAA
established an Aviation Rulemaking Committee under Order 1110.147. This
committee has been chartered to deliver a report on how to optimize
operational benefits of the ADS-B system and to provide recommendations
to the FAA on the rulemaking after the NPRM is published. The scope of
the ARC membership is designed to provide the widest range of inputs
into the development of the NextGen strategy. The FAA will put the ARC
recommendations in the docket established for this rulemaking.
It is this combination of onboard capability and performance
expectations that will enable aircraft in the future to fly safely and
efficiently despite ever-increasing demands on the airspace.
B. The Century of Aviation Reauthorization Act and NextGen
The ``Century of Aviation Reauthorization Act'' was enacted on
December 12, 2003 (Pub. L. 108-176) (the ``Act''). This law set forth
requirements and objectives for transforming the U.S. air
transportation system to meet the needs of the 21st Century. Section
709 of the Act required the Secretary of Transportation to establish in
the FAA a joint planning and development office (JPDO) to manage work
related to NextGen. Among its statutorily defined responsibilities, the
JPDO coordinates the development and utilization of new technologies to
ensure that when available, they may be used to the fullest potential
in aircraft and in the air traffic control system.
The FAA, the National Aeronautics and Space Administration (NASA)
and the Departments of Commerce, Defense, and Homeland Security have
launched an effort to align their resources to develop and further
evolve NextGen. The goals of NextGen, as stated in the Act, that are
addressed by this proposal are:
(1) Improve the level of safety, security, efficiency, quality, and
affordability of the NAS and aviation services;
(2) Take advantage of data from emerging ground-based and space-
based communications, navigation, and surveillance technologies;
(3) Be scalable to accommodate and encourage substantial growth in
domestic and international transportation and anticipate and
accommodate continuing technology upgrades and advances; and
(4) Accommodate a wide range of aircraft operations, including
airlines,
[[Page 56950]]
air taxis, helicopters, general aviation, and UAS.
The JPDO was also charged with creating and carrying out an
integrated plan for NextGen. The Act mandates that the NextGen
Integrated Plan (the ``Plan'') be designed to ensure that the NextGen
system meets the air transportation safety, security, mobility,
efficiency, and capacity needs beyond those currently included in the
FAA's Operational Evolution Plan.\1\ As described in the Plan \2\, the
current approach to air transportation, where ground based radars track
flights along congested airways, and pass information among the control
centers for the duration of the flights, is becoming operationally
obsolete. The current system is increasingly inefficient, and large
increases in air traffic will result in mounting delays or limitations
in service for many areas in the NAS.
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\1\ The Plan was submitted to Congress on December 12, 2004.
\2\ A copy of the Plan has been placed in the docket for this
rulemaking.
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As detailed in the Plan, the demand for air travel is expected to
double within the next 20 years. Current FAA projections are that by
2025, operations will grow to more than half a million departures and
arrivals per year at approximately 16 additional airports. The present
air traffic control system will be unable to handle this level of
growth. Not only will the current method of handling traffic flow not
be able to adapt to the highest volume and density for future
operations, but the nature of the new growth may be problematic, as
future aviation activity will be much more diverse than it is today. A
shift of 2 percent of today's commercial passengers to very light jets
that seat 4-6 passengers would result in triple the number of flights
necessary to carry the same number of passengers.\3\ Furthermore, the
challenges grow with the advent of other non-conventional aircraft,
such as the UAS.
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\3\ Very light jets may revolutionize the industry by permitting
more individuals and corporations to own aircraft. It addition, many
airports that are too small for large jet operations should benefit
because they can support very light jets.
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The future of air transportation contemplated in the Plan is
complex, and the FAA believes that ADS-B technology is a key component
in achieving many of the goals set forth in the Plan. This proposed
rule embraces a new approach to surveillance performance requirements
that can lead to greater and more efficient use of airspace. The Plan
articulates several large transformation strategies to create the
NextGen System. This proposal is a major step toward strategically
``establishing an agile air traffic system that accommodates future
requirements and readily responds to shifts in demand from all users.''
ADS-B technology will assist in the transition to a system with less
dependence on ground infrastructure and facilities, and would provide
for more efficient use of airspace.
C. Today's Radar Environment
In the U.S., Air Traffic Control (ATC) surveillance and aircraft
separation services are provided by the use of primary and secondary
surveillance radar systems. While radar technology has advanced, it is
essentially a product of 1940s World War II technology. Both primary
and secondary radars are very large structures that are expensive to
deploy and maintain; they also require the agency to lease land for
site installation.
Primary radar is a passive detection method that requires no
special equipment aboard the aircraft. It is a technology that
transmits a beam that is reflected by a target. This reflection forms a
return signal that is translated into an aircraft position by ATC
automation systems. Primary radar, however, is not always able to
distinguish aircraft from other objects that reflect radar beams, such
as birds or severe weather, which can result in ``clutter'' on the ATC
radar scope. In addition, with primary radar, ATC is provided only with
an aircraft's position relative to time. It does not provide any other
information about the aircraft.
Primary radar measures both the range and bearing of a particular
aircraft. Bearing is measured by the position of the rotating radar
antenna when it receives a response to its signal that is reflected
from the aircraft. Range is measured by the time it takes for the radar
to receive the reflected response. Detecting changes in an aircraft's
velocity requires several radar sweeps that are spaced several seconds
apart. Because the antenna beam becomes wider as the aircraft travels
farther away from the radar, the accuracy of the radar is a function of
range, and the accuracy decreases as the distance between the aircraft
and the radar site increases. Consequently, aircraft on the outer
fringes of radar coverage or in non-radar areas are separated by
greater distances, directly affecting efficiency and ultimately
capacity in the NAS.
A Secondary Surveillance Radar (SSR) system consists of antennas,
transmitters, and processors installed in ATC facilities, and radio
transponder devices that are installed in aircraft. This system
enhances primary radar by improving the ability to detect and identify
aircraft. An SSR transmits interrogation pulses that elicit responses
from transponders on board the aircraft. A transponder installed on the
aircraft ``listens'' for the interrogation signal and sends back a
reply that provides aircraft information. The aircraft is then
displayed as a tagged icon on the air traffic controller's radar
screen.\4\
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\4\ An aircraft without an operating transponder may still be
observed by ATC using primary radar, but the aircraft will not have
an identifying tag.
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Each transponder category has unique characteristics, operating
functions, and requirements. A transponder with Mode A functionality
requires the pilot to input a discrete code. If the same transponder is
connected with an encoding device then it will also report the
aircraft's altitude (Mode C). Most aircraft operated in general
aviation have Mode A/C transponders. Any aircraft required to have
Traffic Alert and Collision Avoidance System (TCAS) II, or that
voluntarily has TCAS II installed must also be equipped with a Mode S
Transponder. (This generally includes aircraft operated under parts
121, 125, 129 and some aircraft operated under part 135.) Mode S
transponders transmit both aircraft altitude and aircraft
identification information. Both Mode A/C transponders and Mode S
transponders require interrogation to provide information.
To accommodate the projected level of traffic without increasing
delay, more comprehensive surveillance in the NAS, including more radar
sites in certain areas, would be necessary. Even if more radar sites
were commissioned, however, there are many areas in which radar
coverage is not feasible, either geographically (e.g., mountainous
areas) or in a cost-effective manner (e.g., remote areas). Furthermore,
simply increasing the number of radars in the NAS does not solve the
inherent limitation of radar technology, and would not allow the FAA to
reduce current separation standards.\5\ Consequently, the future of air
traffic surveillance cannot be based solely on the use of radar. Radar
technology also lacks the capability to provide services on the flight
deck. However, the FAA is planning to maintain its current network of
primary radars, and expects to be able to reduce a percentage of its
secondary radars. This NPRM does not propose to reduce primary radar
sites.\6\
[[Page 56951]]
Instead, this NPRM would transfer future aircraft surveillance to newer
and more advanced onboard avionics that provide more accurate and
timely aircraft information. ADS-B has been identified as the
technology to facilitate that goal.
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\5\ The FAA currently separates aircraft by 5 NM in the en route
environment and 3 NM in the terminal environment.
\6\ While the FAA expects to be able to reduce a significant
percentage of the national secondary surveillance radar
infrastructure, primary radars will not be decommissioned as a
function of this proposal. Primary radar will serve a role in
surveillance during the transition period of ADS-B avionics
equipage.
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II. The ADS-B System
A. General
The ADS-B system is an advanced surveillance technology that
combines a satellite positioning service, aircraft avionics, and ground
infrastructure to enable more accurate transmission of information
between aircraft and ATC. The system enables equipped aircraft to
continually broadcast information, such as identification, current
position, altitude, and velocity. ADS-B uses information from a
position service, e.g. Global Positioning System (GPS), to broadcast
the aircraft's location, thereby making this information more timely
and accurate than the information provided by the conventional radar
system (which has a latency factor since it is based on interrogation
and reply). ADS-B also can provide the platform for aircraft to receive
various types of information, including ADS-B transmissions from other
equipped aircraft or vehicles. ADS-B is automatic because no external
interrogation is required, but is ``dependent'' because it relies on
onboard position sources and onboard broadcast transmission systems to
provide surveillance information to ATC and ultimately to other users.
Implementation of an ADS-B system would not completely replace the
primary radar or SSR at this time. In addition, ADS-B does not replace
the requirement for transponders. Transponders are still necessary for
SSR, which is the FAA's backup strategy in case of ADS-B failure. For
more information on the backup strategy, see section IV.C.4, Backup
Surveillance Strategy.
The performance requirements for ADS-B avionics proposed in this
NPRM would ensure that the aircraft is broadcasting the requisite
information with the degree of accuracy and integrity necessary for ATC
to use that information for surveillance.\7\ This enhanced surveillance
would provide ATC with the enhanced ability to surveil and separate
aircraft so that efficiency and capacity could increase beyond current
levels to meet the predicted demand for ATC services while continually
maintaining safety. Incremental developments in capacity, efficiency,
and air traffic control procedures based on radar technology cannot
accommodate the anticipated increase in demand for surveillance and
separation services, which could result in delays that would far exceed
those experienced today. Without ADS-B, the increase in demand could
result in increased congestion and the denial of ATC service to some
users of the NAS.
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\7\ An aircraft equipped for ADS-B Out would transmit the
aircraft's position, velocity and other specified, proposed message
elements once per second. Radar data, on the other hand, is
generated approximately once every 3-12 seconds for display to the
air traffic controller depending on whether the aircraft is in the
en route or terminal environment.
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ADS-B technology already has been demonstrated successfully in
Alaska via the Capstone program.\8\ In Alaska, radar coverage is either
very limited or non-existent. ADS-B provides a level of surveillance
performance that previously did not exist and has resulted in increases
in both efficiency and capacity.
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\8\ For additional information on Capstone, see Section VI.
later in the preamble. It should be noted that Special Federal
Aviation Regulation No. 97, Special Operating Rules for the Conduct
of Instrument Flight Rules (IFR) Area Navigation (RNAV) Operations
Using Global Positioning Systems (GPS) in Alaska (68 FR 14072; March
21, 2003), would remain in effect to supplement the requirements in
this proposal as it applies to Alaska.
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``ADS-B Out'' refers to an appropriately equipped aircraft's
broadcasting of various aircraft information. ``ADS-B In'' refers to an
appropriately equipped aircraft's ability to receive another aircraft's
ADS-B Out information. This proposal only seeks to require ADS-B Out;
the FAA is not proposing to require ADS-B In at this time.\9\
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\9\ See Sections IV. later in the preamble for a detailed
discussion of ADS-B Out and V. for a detailed discussion of ADS-B
In.
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B. Ground Infrastructure
Implementing ADS-B in the NAS to provide surveillance requires
avionics, ground infrastructure, automation, and data. This NPRM
addresses the performance requirements for the avionics and the
necessary data that must be broadcast from the aircraft in order for
ATC to use that information for surveillance and separation. The ground
infrastructure involves the installation of a multitude of ground
stations throughout the NAS that first receive the ADS-B Out
transmissions from an aircraft, then relay real-time information based
on those transmissions to ATC facilities. The exact number of ground
stations needed to provide broadcast services across the NAS will be
negotiated as part of the national broadcast service contract. The
preliminary estimate approved by the FAA's Joint Resource Council call
for 548 ground stations to provide coverage NAS-wide and in the Gulf of
Mexico.
On August 30, 2007, the FAA awarded a performance-based service
contract to a consortium led by ITT Corporation. The contract is to
provide ADS-B surveillance uplink (ground-to-air) and downlink (air-to-
ground) services and Automatic Dependent Surveillance Rebroadcast (ADS-
R), Traffic Information Services--Broadcast (TIS-B) \10\, and Flight
Information Services--Broadcast (FIS-B) \11\ services. The vendor will
install and maintain the ground equipment necessary to provide ADS-B
uplink and downlink services to ATC. On November, 30, 2006, the FAA
issued a Screening Information Request to determine which vendors
understand the contract requirements well enough to proceed in the
acquisition process. The FAA's schedule for ADS-B Out calls for all
ground infrastructure, including the provision of broadcast services,
to be in place and available where current surveillance exists by the
end of fiscal year 2013. This schedule will provide reasonably ample
time for operators to equip their aircraft for ADS-B Out and meet the
proposed compliance date of 2020 in this notice.
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\10\ Traffic Information Services--Broadcast (TIS-B) is a
ground-based uplink report to a pilot of proximate traffic that is
under surveillance by ATC but is not ADS-B-equipped. This service
would be available even with limited ADS-B implementation. The
combinations of the surveillance and TIS-B services can enable
pilots to have enhanced visual acquisition of other aircraft. Having
traffic and other flight obstacles on a cockpit display will enable
pilots to more quickly identify safety hazards and communicate with
ATC if necessary. Aircraft that are equipped with ADS-B can be
monitored through a direct reception of their ADS-B signals in an
air-to-air environment.
\11\ Flight Information Services--Broadcast (FIS-B) is a ground-
based uplink of flight information services and weather data. Other
flight information provided by the FIS-B service includes Notices to
Airmen and Temporary Flight Restrictions.
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III. Summary of the Proposal
The FAA is proposing ADS-B Out performance requirements for all
aircraft operations in Class A, B, and C airspace areas in the NAS, and
Class E airspace areas at or above 10,000 feet mean sea level (MSL)
over the 48 contiguous United States and the District of Columbia. This
proposal also would require that aircraft meet these performance
requirements in the airspace out to 30 nautical miles (NM), from the
surface up to 10,000 MSL, around certain identified airports that are
among the nation's busiest. In addition, this proposal if adopted would
require that aircraft meet ADS-B Out performance requirements to
operate in
[[Page 56952]]
Class E airspace over the Gulf of Mexico from the coastline of the
United States out to 12 nautical miles (NM), at and above 3,000 feet
MSL.
The FAA proposes to require aircraft flying at or above Flight
Level 240 (FL240) to have ADS-B Out performance capabilities using the
1090 Extended Squitter (1090ES) broadcast link. Aircraft flying in the
designated airspace below FL 240 would have to use either the 1090ES or
Universal Access Transceiver (UAT) broadcast link. These proposals
would affect all U.S. commercial air carrier operations, foreign-flag
carriers operating in the designated classes of U.S. airspace, air
charter operations, air cargo operations, and a significant portion of
the general aviation fleet operating in the NAS.
The implementation of ADS-B requires two datalinks to support the
full set of applications. UAT is intended to support applications for
the general aviation user community that are not needed by air carriers
because air carriers have weather radar, fly at high altitudes, and
have other aeronautical links. UAT-equipped general aviation aircraft
are not generally equipped with weather radar and would be flying at
low altitudes. The 1090ES link is the internationally agreed upon link
for ADS-B, and is intended to support applications for air carriers and
other high-performance aircraft. The 1090ES broadcast link does not
support applications available from FIS-B, like weather and related
flight information. This is because of the bandwidth limitations of the
1090ES link for transmitting the large message structures required by
FIS-B. Weather and flight information for 1090ES-equipped aircraft is
generally provided by commercial products.
As described in the Plan, large increases in air traffic would
result in mounting delays or limitations in service for many areas if
the current surveillance system is not modified. An environment in
which aircraft meet the proposed ADS-B Out performance requirements
would result in greater capacity and efficiency in the NAS, maintain
safety, and provide a flexible, expandable platform to accommodate
future traffic growth while avoiding possible system delays and
limitations in service.
In moving forward with a performance-based surveillance system, the
FAA believes that communication with the affected industry is critical.
The FAA hosted several Industry Days to brief the technology, the
rulemaking and procurement processes and associated milestones to
interested parties, including manufacturers and affected operators. As
with any rulemaking, the FAA invites comments on the various elements
of this proposal, and all comments will be carefully considered. If
this proposal is adopted as a final rule, it may be modified in view of
the submitted comments.
IV. The Proposal for ADS-B Out
A. Advantages of ADS-B Out
ADS-B Out, as proposed in this notice, would enhance surveillance
and broadcast services in both the en route and terminal environments
and provide ATC with more accurate information to safely separate
aircraft in the air.
In today's radar surveillance environment, accuracy and integrity
of radar information is a function of range and decreases as the
distance between the radar antenna and the aircraft increases. Unlike
radar, both the accuracy and integrity of ADS-B Out is uniform and
consistent throughout the service area. A comprehensive, national
surveillance system that utilizes ADS-B Out would provide ATC with the
ability to accurately identify and locate aircraft that are either far
away from the ATC facilities or at the outer boundaries of ground
station service volume.
If ATC had more precise aircraft position information, it could
position, separate, and provide speed and direction instructions to
aircraft with improved precision and timing. This would result in the
use of optimal flight paths and altitudes. This transmission of
information would enable improvement of airspace capacity throughout
the NAS. Additionally, with ADS-B Out, ATC would receive updated
information broadcast by aircraft more frequently than with radar, and
would be able to track a more closely monitored flight path. This would
result in ATC providing fewer instructions to pilots, thus having more
time to accommodate additional aircraft within the allotted airspace.
These improved efficiencies for ATC ultimately should accommodate the
increased number of aircraft able to operate in the NAS. In addition,
we expect a reduction in aircraft fuel burn because better surveillance
provides for more efficient use of the airspace, provides for optimal
aircraft routing, and addresses the limits currently experienced with
radar.
In the terminal radar environment today, ATC may have to request
pilots to provide aircraft speed, heading, and in some cases, aircraft
identification. Neither the primary radar nor SSR systems provide all
that information. With ADS-B, ATC is automatically provided aircraft
speed, heading, and other identifying information, including aircraft
size, which are necessary to safely position and separate aircraft more
rapidly than is possible today.
While more precise ADS-B derived aircraft position information
improves ATC efficiencies under current separation standards, the
potential for significantly greater capacity and efficiency gains may
be realized by reducing separation standards between aircraft.
Therefore, this rulemaking is expected to help achieve a level of
surveillance accuracy that would support reducing aircraft separation
standards. ADS-B is an essential component of the NextGen platform and
is necessary to achieve a level of capacity in the NAS commensurate
with future growth.
B. Avionics
This discussion first addresses the broadcast message links
necessary to transmit aircraft information to the ground stations and
the specific message elements that would be broadcast by the aircraft
comprising the ADS-B Out transmission. Next we discuss the navigation
position sensor and the necessary accuracy and integrity of the ADS-B
message. Finally, we explain the necessary requirements for antenna
diversity on the aircraft, and the required latency of the data in the
ADS-B transmission from the aircraft.
1. 1090ES and UAT Broadcast Links
In 2002, the United States determined that two frequencies would be
appropriate for ADS-B: 1090MHz and 978MHz. To broadcast the necessary
data elements for ADS-B Out transmission under this proposal, aircraft
would have to be equipped with either 1090ES or UAT that meet the
latest version of either Technical Standard Order (TSO)-C166a or TSO-
C154b, respectively.\12\ Today, operators of air carriers and many
private/commercial aircraft already are primarily equipped with
avionics designed under TSO-C112, Air Traffic Control Radar Beacon
System/Mode Select (ATCRBS/Mode S), which are required to function with
the Traffic Alert and Collision Avoidance System
[[Page 56953]]
(TCAS II) or ACAS.\13\ Many TSO-C112 Mode S Transponders can be
modified or are designed to provide 1090ES functionality under TSO-
C166a. Most other general aviation aircraft, typically small aircraft
operated in non-commercial service (that are not required to have TCAS
II), would likely use the UAT broadcast link for ADS-B Out, which
operates on the 978MHz frequency. Today, a small number of aircraft are
equipped with UAT ADS-B In and are capable of receiving TIS-B and FIS-B
services. While the 1090ES link does not support FIS-B, it does support
TIS-B.
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\12\ A TSO is a minimum performance standard issued by the
Administrator for specified materials, parts, processes, and
appliances used on civil aircraft. TSO-C166a sets the minimum
performance standards for Extended Squitter Automatic Dependent
Surveillance--Broadcast (ADS-B) and Traffic Information Service
Broadcast (TIS-B) Equipment Operating on the Radio Frequency of 1090
MHz. TSO-C154b sets the minimum performance standard for Universal
Access Transceiver (UAT) Automatic Dependent Surveillance--
Broadcast (ADS-B) Equipment.
\13\ Airborne Collision Avoidance System (ACAS) is comparable to
TCAS II and is specified for use in Europe.
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In December 2006, RTCA \14\ published RTCA/DO-260A, Change 2,
``Minimum Operational Performance Standards (MOPS) for 1090 MHz
Automatic Dependent Surveillance--Broadcast (ADS-B).'' This change
revised RTCA/DO-260 1090ES MOPS. The major differences between RTCA/DO-
260 and RTCA/ DO-260A are refinements of the Navigation Integrity
Category (NIC), Navigation Accuracy Category (NAC), and Surveillance
Integrity Level (SIL) parameters, which significantly improve the
overall performance and interoperability of the ADS-B Out broadcast
link. These modified parameters (NIC, NAC, and SIL) provide a level of
accuracy and integrity with respect to the information transmitted in
the ADS-B Out message that would enable ATC to provide improved
surveillance and separation services based on the information it
receives from the aircraft.
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\14\ RTCA, Incorporated is a not-for-profit corporation formed
to advance the art and science of aviation and aviation electronic
systems for the benefit of the public. The organization functions as
a Federal Advisory Committee and develops consensus-based
recommendations on contemporary aviation issues. The organization's
recommendations are often used as the basis for government and
private sector decisions as well as the foundation for many TSOs.
---------------------------------------------------------------------------
After RTCA issued its updates in December 2006, the FAA
subsequently issued TSO-C166a, which adopted the recent modifications
specified in change 2 to RTCA/DO-260A, and characterizes the parameters
of NIC, NAC, and SIL.\15\ There are some aircraft equipped today with
legacy 1090ES ADS-B systems. Operators of these aircraft would need to
modify their broadcast link equipment to meet the proposed requirements
defined in TSO-C166a. This modification could include hardware,
software, or both depending upon other avionics installed on the
aircraft.
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\15\ TSO-C166a superseded TSO-C166.
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The transition to TSO-C166a and TSO-C154b has been identified as a
requirement for use of ADS-B in the required airspace. The United
States faces unique challenges in air traffic control due to its high
density airspace and stringent safety requirements. In order to
maintain safety and capacity, given a state of increased air traffic,
advanced surveillance technologies will be necessary. The earlier
standards in RTCA/DO-260 do not provide the performance standards
necessary to meet the requirements of the NAS. RTCA/DO-260a provides a
means to transmit the Secondary Surveillance Radar beacon codes that
currently service the NAS and will continue to be required as a backup
to ADS-B. RTCA/DO-260 does not provide that compatibility.
The International Civil Aviation Organization (ICAO) is in the
process of updating the 1090ES Standards and Recommended Practices
(SARPs) published in ICAO Annex 10, Amendment 77, to include those
requirements identified in the publication of RTCA/DO-260A, Change 2.
These updated SARPs are expected to become effective in November 2007.
Operators may, under this proposal, also choose to equip with dual
link avionics, i.e. 1090ES and UAT, which would provide the capability
to transmit and receive information on both broadcast links at the same
time.
If an aircraft is to operate at or above FL240, which is discussed
further in section IV.b.3. of this preamble (``Broadcast Link
Requirements for Different Flight Levels''), the aircraft's broadcast
link capabilities would have to meet the minimum performance
requirements of TSO-C166a, (i.e., be equipped with 1090ES).
Consequently, those aircraft operating at or above FL240 with Mode A/C
transponders would need new transponders. Aircraft with Mode S
transponders without compatible extended squitter capability installed
would need to be reequipped with those providing 1090ES functionality,
or supplement them with 1090ES to operate at or above FL240.
In December 2006, RTCA also issued RTCA/DO-282A, Change 1 for UAT,
which clarified the definitions of the NIC, NAC, and SIL similar to
those specified for 1090ES discussed above. TSO-C154b adopted the
requirements of RTCA/DO-282A and clarifies performance parameters
capable of ensuring interoperability with ground stations deployed to
support the Capstone program in Alaska, and to provide for future NAS
interoperability assurances. Aircraft equipped with UAT must meet the
minimum performance standards in TSO-C154b, or later version. There are
very few aircraft equipped with legacy UAT equipment. Operators of
those aircraft would need to modify their equipment to meet the
performance standards of TSO-C154b.
2. Broadcast Link Requirements for Different Flight Levels
The FAA proposes to require that aircraft flying at or above FL240
have ADS-B Out performance capability using the 1090ES broadcast link.
For operations below FL240, operators could equip their aircraft with
either the 1090ES or UAT broadcast links. Some general aviation
aircraft are already equipped with the UAT broadcast link, and most
general aviation operators are expected to equip with UAT under this
proposal in order to have TIS-B and FIS-B services. Larger aircraft,
particularly the transport category aircraft, generally operate at
higher altitudes and are already equipped with 1090ES that meets TSO-
C166 (which would require modification to upgrade to TSO-C166a under
this proposal) or have equipment installed that uses the 1090 broadcast
link. Furthermore, the international aviation communities, and for the
most part, foreign-flag aircraft operating in the U.S., tend to operate
large transport category aircraft that also operate at the higher
altitudes. Having a single broadcast link at higher altitudes would
enable aircraft equipped for ADS-B In to benefit from potential future
applications such as aircraft merging and spacing, and self-separation.
These applications are enabled by having aircraft identify each other
on the same data link without the need to employ ADS-R, which would
increase the latency of the transmission. The FAA believes that the
approach articulated in the proposal to require 1090ES for operations
at and above FL240 is largely consistent with how those affected
operators would choose their respective broadcast link. While this NPRM
does not require equipage for ADS-B In, we fully recognize that
operators may choose to equip for that capability and that it is
reasonable to lay the foundation so that operators may be able to take
advantage of future applications if they so choose.
3. Part 91 Appendix H--Broadcast Message Elements
The FAA is proposing to add an appendix to 14 CFR part 91 to
specify the broadcast message elements necessary for ADS-B Out. These
message elements contain the data necessary for ATC to support aircraft
[[Page 56954]]
surveillance by ADS-B. The message elements required support future
NextGen air-to-air applications such as reduced horizontal separation
and self separation. These message elements also support the capability
for aircraft avionics to be verified during normal operations for
continuing airworthiness in lieu of conducting ground checks of the
avionics. We believe the message elements allow for further NextGen
capabilities, at least to the extent we can predict those future needs
at this time. However, in the future, additional elements such as
predictive aircraft movement could be added to enable further
capabilities.
These elements would be broadcast automatically from the aircraft
except where pilot entry is necessary. Pilot entry would be necessary
for elements (g) through (k). The following is a description of each
message element.
(a) The length and width of the aircraft. This message element
would provide ATC with quick reference to the aircraft's dimensions. On
airport surfaces in particular, aircraft are in close proximity to each
other and this information would facilitate ATC's ability to use the
most appropriate landing and surface movement procedures for individual
aircraft in managing traffic on the airport surfaces. This information
would be pre-set when avionics equipment meeting the standards in TSO-
C166a or TSO-C154b, as applicable, is installed on the aircraft.
(b) An indication of the aircraft's lateral and longitudinal
position. This message element is derived from the aircraft's
navigation position sensor \16\ and would provide an accurate position
based on latitude, longitude, and accuracy values for the display of
information in a format that meets ATC requirements. This information
is critical to the safe and efficient separation of aircraft.
---------------------------------------------------------------------------
\16\ The aircraft's navigation position sensor is discussed in
detail in section IV.4. of this preamble.
---------------------------------------------------------------------------
(c) An indication of the aircraft's barometric pressure altitude.
This message element would provide ATC with the aircraft's altitude
information. Currently, Sec. 91.217 requires Mode C and Mode S
transponders to transmit pressure altitude. It is critical that the
altitude transmitted by the Mode C and Mode S transponders is identical
to that in the ADS-B transmission. Therefore, in addition to this
proposed data element, we believe that Sec. 91.217 should be amended
as well. Section 91.217 requires Mode C and Mode S transponders to
transmit pressure altitude. We propose to revise Sec. 91.217 to also
apply to the ADS-B transmission of altitude to ensure that the reported
altitude from various avionics is consistent.
(d) An indication of the aircraft's velocity. This message element
is also derived from the aircraft's navigation position sensor and
would provide ATC with the aircraft's airspeed with a clearly stated
direction and describes the rate at which an aircraft changes its
position.
(e) An indication if TCAS II or ACAS is installed and operating in
a mode that may generate resolution advisory alerts. This information
would identify to ATC whether an aircraft is equipped with TCAS II or a
later version or its European equivalent ACAS, and whether that
equipment is operating in a mode that may generate resolution advisory
alerts.
(f) For aircraft with an operable TCAS II or ACAS, an indication if
a resolution advisory is in progress. Both TCAS II and ACAS improve
safety by detecting impending airborne collisions or incursions and
issuing commands to the pilot on how to avoid the hazard by climbing or
descending. If two aircraft get too close to each other, the aircrafts'
TCAS II or ACAS systems will provide a resolution advisory (RA), which
gives the pilots a command to climb or descend to avoid the other
aircraft. The RA command is provided independent of ATC instructions.
It is critical for ATC to know why an aircraft is climbing or
descending, i.e., responding to an RA, ATC instruction, or a previous
flight plan path. ATC may respond more efficiently and safely in
managing the air traffic environment by knowing whether an aircraft is
responding to an RA.
(g) An indication if ATC services are requested. (Requires flight
crew entry.) This message element would identify to air traffic
controllers if services are requested and whether the aircraft is in
fact receiving ATC services.
(h) An indication of the Mode 3/A transponder code specified by
ATC. (Requires flight crew entry.) All transponder-equipped aircraft on
Instrument Flight Rules (IFR) flights are directed by ATC to ``squawk''
a unique four-digit code, commonly referred to as a ``Mode 3/A
transponder code.'' All transponder equipped aircraft on Visual Flight
Rules (VFR) flights are directed by ATC to squawk 1200. The assigned
Mode 3/A transponder code is used by ATC to identify each aircraft
operating under IFR, and the 1200 transponder code identifies aircraft
operating under VFR.
An aircraft equipped with ADS-B Out continually broadcasts its
state vector (3-dimensional position and 3-dimensional velocity). It is
critical for ATC to correlate and verify that the ADS-B Out information
transmitted from each aircraft is displayed and identified correctly on
the ATC radar display. Therefore, it is imperative that the ATC-
assigned transponder code be identical to the assigned transponder code
in the ADS-B Out message. If the aircraft's avionics are not capable of
allowing a single point of entry for the transponder and ADS-B Out Mode
3A code, the pilot would have to ensure that conflicting codes are not
transmitted to ATC. Operational procedures would have to be developed,
including specific guidance, instructions, or training material
provided by the equipment manufacturer, as well as the operator
training programs, manuals, Operations Specifications, and Letters of
Authorization, to ensure that conflicting codes are not transmitted to
ATC.
(i) An indication of the aircraft's call sign that is submitted on
the flight plan, or the aircraft's registration number. (Aircraft call
sign requires flight crew entry.) This message element would correlate
flight plan information with the data that ATC views on the radar
display and facilitate ATC communication with the aircraft. The
aircraft's call sign or registration number broadcast in the ADS-B
message would have to be identical to information contained in its
flight plan.
(j) An indication if the flight crew has identified an emergency,
and if so, the emergency status being transmitted. (Requires flight
crew entry.) This message element would alert ATC that the aircraft is
experiencing emergency conditions and indicate the type of emergency.
Applicable emergency codes would be found in the Aeronautical
Information Manual. This information would alert ATC to potential
danger to the aircraft so it could take appropriate action.
(k) An indication of the aircraft's ``IDENT'' to ATC. (Requires
flight crew entry.) ATC may request an aircraft to ``IDENT,'' to aid
controllers to quickly identify a specific aircraft. The pilot manually
inputs the aircraft's identity, which then highlights the aircraft on
the ATC scope. When activated, this message element allows
identification of the aircraft with which ATC is in communication.
(l) An indication of the aircraft's assigned ICAO 24-bit address.
ICAO 24-bit codes are unique and assigned to each individual aircraft.
These codes are necessary for aircraft used for international
operations. This code would provide the FAA with the future capability
to identify aircraft using the
[[Page 56955]]
ICAO 24-bit address. This capability addresses limits on future
capacity due to the finite number of aircraft that can be tracked with
discrete transponder codes.
(m) An indication of the emitter category. If ATC knows the emitter
category, it can determine separation minima based in part on a
particular aircraft's wake vortex. This information would be used to
provide air traffic controllers and ground crews with more efficient
information regarding a particular aircraft's constraints and
capabilities. Once the emitter category is set at installation, it
would not change. (Refer to TSO-C166a or TSO-C154b for additional
information.) Some examples of emitter categories to be used (as
specified in RTCA DO-260A, DO-242A, and DO-282A) include, but are not
limited to, the following:
Light (ICAO)--7,000 kg (15,500 lbs) or less.
Small aircraft--7,000 kg to 34,000 kg (15,500 lbs to
75,000 lbs).
Large aircraft--34,000 kg to 136,000 kg (75,000 lbs to
300,00 lbs).
High vortex large (i.e., B-757).
Heavy aircraft (ICAO)--136,000 kg (300,000 lbs) or more.
Rotorcraft.
(n) An indication whether a cockpit display of traffic information
(CDTI) is installed and operable. This message element would alert ATC
as to whether an aircraft has an operable CDTI \17\ installed. A CDTI
is necessary for aircraft to have ADS-B In capability. This message
element would indicate to ATC which aircraft are capable of receiving
ADS-B In services.
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\17\ CDTI is the function of presenting surveillance traffic
information (e.g., airborne or surface) to the flight crew. To
display traffic, the CDTI may use a dedicated display or a shared
multi-function display (MFD) device. The CDTI is capable of
displaying position information for nearby aircraft and ADS-B-
equipped airport surface vehicles. The CDTI consolidates ADS-B
traffic targets, terrain, weather, and other products relative to
the pilot's own aircraft or flight operation. It allows pilots to
display textual and graphical information provided by the ADS-B
System and Broadcast Services.
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(o) An indication of the aircraft's geometric altitude. The
geometric altitude is a measure of altitude provided by a satellite-
based position service, determined mathematically, based on a three-
dimensional position in space. This message element is necessary to
confirm accuracy or discrepancies between geometric and barometric
altitude, which changes as a function of air pressure in the
environment. The message element would serve as a tool for validating
positioning services.
4. Navigation Position Sensor and the Accuracy and Integrity of the
ADS-B Message
ADS-B Out continuously transmits aircraft information through the
selected broadcast data links of 1090ES or UAT. The aircraft's lateral
and longitudinal position and velocity are proposed data elements
transmitted in the broadcast message. The navigation position sensor is
equipment onboard the aircraft that computes a geodetic position
(latitude and longitude) that can be a separate sensor or integrated
into other navigation equipment or system onboard the aircraft.
(Examples of such equipment are LORAN C, GPS, GPS-WAAS, DME/DME and
Inertial Reference Unit (IRU).)
The accuracy and integrity of these broadcast message elements
transmitted from the aircraft to the ground stations depends on the
aircraft's navigation position sensor and the signal source from which
the position is derived. The accuracy and integrity of the transmitted
aircraft position and velocity are critical for use in surveillance and
various airborne and surface applications. The accuracy and integrity
of transmitted information expressed by ADS-B avionics is measured by
the Navigation Accuracy Category for Position (NACp), the Navigation
Accuracy Category for Velocity (NACv), the NIC and the SIL.
An aircraft transmitting its position and velocity with the
accuracy and integrity proposed in part 91, Appendix H, Section 3 (ADS-
B Out Performance Requirements for NIC, NAC, and SIL) would be more
accurately identified by ATC than it would be in today's radar
environment. The confidence with respect to the accuracy of the
position and velocity reported by ADS-B Out would enable the future
applications discussed further in this proposal that simply could not
be provided by existing surveillance systems. While existing
surveillance systems provide information that is sufficient for
separation purposes and the capacity needs of today's traffic
environment, a more responsive and versatile ATC system will need
improved accuracy and integrity of broadcast information for future
surveillance performance. The values proposed would ensure that the
information ATC receives has the level of performance and the requisite
confidence in the accuracy of that information necessary to control
aircraft. Increasing the quality and standards for surveillance
information presents new opportunities for efficiency and capacity
improvements in the NAS, and the potential for future self-separation
or air-to-air applications of ADS-B.
The NACp specifies the accuracy of the aircraft's horizontal
position information (latitude and longitude) and the vertical
geometric position transmitted from the aircraft's avionics. All
aircraft position information has a margin of error and the accuracy
category specifies that margin. The NACp specifies with 95 percent
probability that the reported information is correct within an
associated allowance. (The horizontal 95% bound error allowance
resembles an imaginary circle around the aircraft with a radius
equivalent to the NACp defined value.) ATC and aircraft equipped for
ADS-B In would monitor the NACp reporting to ensure that the accuracy
supports the intended operational use. Not all navigation position
sensors are capable of providing the necessary aircraft information
with the accuracy and integrity needed to support certain surveillance
applications.\18\ In order to use ADS-B Out for surveillance and
separation, the NACp value must have a small margin of error in
position reporting.
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\18\ Surveillance applications are discussed further in Section
V of this NPRM.
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In today's radar surveillance environment, aircraft position
accuracy is required to be within 0.3 NM for operations in the en route
airspace, and 0.1 NM for operations within terminal area airspace. An
aircraft broadcasting its position with a NACp equal to or greater than
7 would provide a horizontal position accuracy of at least 0.1 NM with
no specific requirement for vertical (geometric) position accuracy.
Aircraft position reported at a NACp equal to or greater than 7 would
meet the minimum radar accuracy requirement for terminal area
operations and exceed radar performance for en route operations.
Therefore, the FAA believes that the minimum accuracy requirement
necessary to maintain an equivalent level of surveillance in the
terminal airspace area (and provide for equivalent separation as that
in today's radar environment) would be a NACp of 7. The FAA is not,
however, engaging in this rulemaking simply to meet the level of
surveillance that exists in the current infrastructure, or to establish
a new surveillance system that would only enable separation performance
equivalent to that realized today. ADS-B performance is intended to go
beyond today's standards for accuracy and provide a platform for
NextGen. In order to accomplish that goal, we propose a minimum
accuracy value of NACp 9 in
[[Page 56956]]
all airspace areas that ADS-B would be required. This proposed accuracy
requirement would provide horizontal position information for ADS-B Out
equipped aircraft to within 30 meters (0.016NM) horizontally and
vertical (geometric) position accuracy to within 45 meters. This
proposed accuracy requirement could make it possible for future
airspace separation to be reduced from today's current separation
minima. At this time the FAA cannot determine the extent to which
separation standards might be reduced. Significant testing and
certification is required before any reduction in separation standards
might be applied. The FAA may examine the possible reduction of
separation standards once ADS-B has been certified to meet existing
separation standards safely and consistently.
Under this proposal, any aircraft not operating with at least this
level of performance would not be permitted in the designated airspace
without first obtaining authorization from ATC. If the aircraft
broadcast message element for position has an NACp of less than 9, ATC
would be notified and it could choose to revert to a backup system or
apply procedural mitigation.
This proposed NACp of 9 would also provide the necessary accuracy
to enable certain applications on the surface at the nation's busiest
airports. For various operational applications including situational
awareness and traffic alerting, it would be necessary for aircraft
position accuracy to be transmitted with an error of 30 meters or less
horizontally, particularly for surface operations. The proposed
requirement for an NACp equal to or better than 9 would meet the 30
meter or less performance requirement for surface operations and would
apply to all aircraft equipped with ADS-B Out. If the aircraft
broadcast message element for position has an NACp of less than 9, ATC
and aircraft equipped with ADS-B In would be automatically notified
that the ADS-B Out performance for a particular aircraft is degraded
and therefore, the information is unusable to support either
situational awareness on the surface or awareness of runway occupancy
on approach to airports. The NACp values are specified in greater
detail in RTCA/DO-260A and RTCA/DO-282A, which are recognized
performance standards by the applicable TSOs identified under this
proposal.
The NACv is a measured value similar to the NACp value except that
it applies to the computed velocity derived from navigation position
sensor or navigation system. In accordance with TSO-C166a and TSO-
C154b, which recognize the performance standards of DO-260A and DO-282A
respectively, the NACv must be greater than or equal to 1. This means
that the estimate of aircraft velocity must be accurate to within 10
meters per second and must be reported with 95 percent probability.
NIC differs from NAC in that a NIC value specifies aircraft
integrity containment often referred to as the ``containment radius,''
which is the maximum error for the broadcast position as described in
RTCA/DO-260A, Change 2 and DO-282A, Change 1. NIC and NAC performance
values will vary depending upon the positioning service and navigation
position sensor. NIC/NAC values may be enhanced or degraded by external
NAS infrastructure or by characteristics of avionics systems
performance. For instance, a GPS outage would interrupt the integrity
and accuracy of the broadcast information. Avionics failures also could
degrade expected performance. The NIC value is broadcast so that
surveillance services may determine whether the horizontal and vertical
(geometric) position meets an acceptable level of integrity containment
for the intended operation or phase of flight. For ADS-B Out, the FAA
proposes a NIC value of 7. This value would bound the error to within
0.2 NM. The NIC parameter combined with the SIL parameter described in
the next paragraph provides integrity assurance in broadcast position.
The SIL specifies the ADS-B Out avionics integrity level and the
probability that the position error may be larger than the reported
NIC. The SIL may be configured at the time of installation. SIL is
typically based on the design assurance level \19\ of the ADS-B Out
avionics and its navigation position sensor. While a NIC value varies
based on computed navigation sensor position, SIL is typically a static
(unchanging) value for the ADS-B Out avionics. For example, while the
NIC is dependent on the satellite constellation (or number of available
satellites), the SIL's reporting of the installed ADS-B avionics is not
dependent upon the satellite constellation and would not be affected by
changes in the number of available satellites being used in the derived
position. To achieve performance at least equivalent to existing radar
systems, the FAA proposes a SIL of 2 or better. This value would
provide integrity assurance that meets a failure rate probability of
99.999 per flight hour.
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\19\ ADS-B Out avionics design assurance is dependent on both
the hardware and software levels. There are 5 hardware design
assurance failure classifications; (1) Catastrophic, (2) Hazardous/
Severe-Major, (3) Major, (4) Minor, and (5) No Safety Effect. RTCA/
DO-178B ``Software Considerations in Airborne Systems and Equipment
Certification'' software classifications are; (1) Level A, (2) Level
B, (3) Level C, (4) Level D, and (5) Level E which directly map to
the hardware design assurance failure classifications. The minimum
requirement for systems development assurance for ADS-B Out is a
hardware design assurance (failure classification) of ``major''
dependent upon RTCA/DO-178B Level ``C'' software.
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The proposed NIC, NACp, NACv, and SIL requirements would support
not only ATC services, but also advisory applications for those who
choose to equip aircraft with ADS-B In. The proposed values for
accuracy and integrity would meet the needs of all the ADS-B In
applications discussed in this proposal. Terminal area and surface
applications such as Final Approach and Runway Occupancy Awareness
would not be enabled unless all aircraft in the surface environment
report their position accurately on runways and taxiways (NACp equal to
or greater than 9). Universal compliance with accuracy and integrity
requirements would ensure that ADS-B In applications could provide
accurate data even in a closely spaced environment such as an airport
surface.
This proposal specifies performance standards for aircraft avionics
equipment for operation to enable ADS-B Out. These performance
standards would accommodate and facilitate the use of new technology.
Presently, GPS augmented by the Wide Area Augmentation System (WAAS) is
the only navigation position service that provides the level of
accuracy and integrity (NIC, NACp, and NACv) to enable ADS-B Out to be
used for NAS-based surveillance operations with sufficient
availability. The FAA is considering whether other navigation position
systems such as the Global Navigation Satellite System (GNSS) combined
with tightly coupled inertial navigation systems are also capable of
meeting the proposed performance standards. Other types of positioning
systems that meet the requisite performance requirements may be
developed in the future, and may include satellite constellations
similar to the Galileo system, or tightly coupled IRU to existing GPS.
At this point, however, the agency is still studying the ability of
these other navigation position systems to meet the performance
standards articulated in this proposal.
In order to meet the proposed performance requirements using the
GPS/WAAS system, aircraft would be required to have equipment installed
onboard the aircraft that meets one of the following: (1) TSO-C145b,
Airborne Navigation Sensors using the GPS augmented by WAAS; or (2)
TSO-C146b Stand-Alone Airborne Navigation
[[Page 56957]]
Equipment using the GPS augmented by WAAS.
5. ADS-B Aircraft Antenna Diversity and Transmit Power Requirements
The aircraft antenna is an important part of the overall ADS-B Out
system because antennas are major contributors to the system link
performance. The location, number of antennas and transmit power
required for the airborne ADS-B Out system is a function of the
equipment class for the selected broadcast link (UAT or 1090ES). This
proposal specifies the classes of 1090ES and UAT equipment that would
meet the performance standards for ADS-B Out. The equipment classes
include requirements for aircraft antenna diversity and transmit power,
as explained below.
Optimal link performance requires both a top and bottom antenna
(antenna diversity). Accordingly, the agency is proposing to require
that the aircraft be equipped with both a top and bottom antenna to
support ADS-B Out applications as well as future air-to-air ADS-B In
applications. Antenna diversity is a requirement of the equipment
classes identified in the proposed rule.
For aircraft already equipped with a Mode S transponder (TSO-C112),
which incorporates antenna diversity, no additional antennas would be
required for ADS-B Out using 1090ES. For ADS-B In, however, additional
1090 MHz receive antennas may be necessary depending on the additional
avionics equipment installed on the aircraft. It may be possible to
share the TCAS 1090 MHz receiver, as long as it can be shown that TCAS
performance is not degraded. This shared approach is addressed in TSO-
C166a.
For ADS-B installations using UAT, it may be possible to share the
aircraft's existing bottom ATCRBS transponder (TSO-C74c) antenna
through the use of an antenna diplexer, thus only requiring
installation of a top antenna. Specifications for the diplexer are
addressed in TSO-C154b. This dual antenna system would not result in
degraded performance relative to that which would have been produced by
a single system having a bottom-mounted antenna.
Antennas would also have to transmit their signal at a certain
level of power in order to ensure that transmitted signals are received
by ground stations, and by ADS-B In equipped aircraft and vehicles. The
UAT requires a 16 watt minimum transmit power. Therefore, aircraft
equipped with the UAT would be required to have Class A1H, A2, A3, or
B1 equipment, as defined in TSO-C154b. The 1090ES broadcast link
requires a 125 watt minimum transmit power. Correspondingly, aircraft
operating with 1090ES would also be required to have Class A1, A2, A3
or B1 equipment, as defined in TSO-C166a. The transmitted power level
supports the coverage requirements for each equipment class, including
the impact of loss of antenna system performance.
These proposed antenna requirements are necessary so that receivers
of the ADS-B system on the ground and in other aircraft could receive
ADS-B Out messages with sufficient strength, consistency, and update
rate to provide the necessary information for surveillance and
broadcast services.
6. Latency of the ADS-B Out Broadcast Message Elements
This proposal defines the latency for the ADS-B message from the
time information enters the aircraft through the aircraft antenna(s)
until the time it is transmitted from the aircraft. A specific limit
between the time the information is received and then processed through
onboard avionics is necessary to ensure timely transmission of
information and to realize the benefits of the ADS-B system. As
discussed previously, ADS-B Out transmits accurate and timely
information more frequently than information transmitted under the
current radar surveillance system. With ADS-B, information is sent to
the aircraft from satellites, processed on the aircraft and sent to
ground stations. The information would enter the aircraft through an
antenna(s), be processed by the onboard avionics (e.g., navigation
sensor, navigation processor, and either 1090ES or UAT broadcast
links), then transmitted to the ground stations through another
antenna(s) on either the 1090 or 978 MHz frequencies, depending upon
the aircraft's avionics.
Under this proposal, the navigation sensor would process
information received by the aircraft's antenna(s) and forward this
information to the ADS-B broadcast link avionics in less than 0.5
seconds. That processed information would then be transmitted in the
ADS-B message from the ADS-B Out broadcast link avionics in less than
1.0 second from the time it was received from the navigation sensor.
This latency would support the proposed requirement that the aircraft
transmit its position and velocity at least once per second while
airborne, or while the aircraft is moving on the surface. Additionally,
the aircraft would be required to transmit its position information at
least once every 5 seconds while stationary on the airport surface.
Latency requirements for the reception and processing of ADS-B Out
by the ground station for display to the ATC automation system are
described in the FAA surveillance and broadcast services acquisition
documents.\20\
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\20\ Final Program Requirements for Surveillance and Broadcast
Services, En Route and Oceanic Services, Air Traffic Organization,
Federal Aviation Administration.
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7. Maintenance
This NPRM would not require additional maintenance requirements for
the installation of ADS-B avionics equipment. The current requirements
of 14 CFR 21.50, ``Instructions for continued airworthiness and
manufacturer's maintenance manuals having airworthiness limitations
sections,'' are applicable to all ADS-B equipment. Since any alteration
of equipment is subject to the requirements of that section, the
existing requirements would apply to any new avionics equipment
installed in an aircraft.
C. Operational Procedures
1. Applicability
With specific and limited exceptions, the ADS-B Out performance
requirements proposed here would apply to all aircraft operating in
certain U.S. designated airspace.\21\ These requirements would be
applicable to operations conducted by domestic and foreign operators in
U.S. territorial airspace. The efficiency and capacity benefits that
can be realized with ADS-B Out are largely obtainable if all aircraft
are equipped for ADS-B Out broadcast. There are some aircraft, however,
that were not originally certified with an electrical system, or that
have not been subsequently certified with such a system installed, for
which installation of equipment that meets ADS-B Out performance
standards is impractical. These aircraft may include certain airplanes,
balloons, and gliders. There may be instances where a pilot of an
aircraft without an electrical system (such as a glider) may want to
operate in airspace where ADS-B Out performance standards would be
required under this proposal. The procedures for requesting
authorization to enter the airspace where ADS-B is required would be
the same procedures used today for aircraft not equipped with a
transponder to enter certain airspace. In these cases, an operator may
request an ATC authorization to operate
[[Page 56958]]
in the airspace and the FAA addresses those requests on a case-by-case
basis. In formulating this proposal, the FAA considered various options
including whether to require ADS-B Out performance standards for
aircraft based on the type of operation conducted (e.g., part 121 and
135 operations), or based on the type of aircraft (e.g., large or
small). The agency concluded that there is no distinguishing
operational need for differing performance standards based on aircraft
type or category of the operation, as many different types of operators
and aircraft operate in the same airspace.
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\21\ See section IV.c.2. for a further discussion of the
airspace where ADS-B Out would be required.
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The FAA also considered proposing ADS-B Out performance standards
for aircraft operations at and above specified altitudes. Since
aircraft operate at various altitudes between the en route and terminal
environments, this option was dismissed as confusing to pilots and
impractical to implement. ADS-B requirements based on specific
altitudes could result in different equipment requirements applying
within different segments of the same class of airspace.
Lastly, the FAA considered whether to propose ADS-B Out for all
aircraft operations in domestic airspace (Classes A-G). Domestic
airspace includes airspace over the territorial United States that
extends out to 12 NM from the coastline that is controlled by ATC
(Classes A, B, C, D, and E) and uncontrolled airspace (Classes G).
While this would result in almost 100% of aircraft meeting ADS-B Out
performance requirements and increase the number of identifiable
aircraft in the NAS, it also would place an unnecessary financial and
operational burden on aircraft operators who do not operate in
controlled airspace, or who are not under ATC surveillance.
2. Airspace
In February 1988, the FAA promulgated an ATC transponder and
altitude reporting equipment final rule, which established Sec. 91.215
of 14 CFR and articulated the operating requirements for ATC
transponder and altitude reporting equipment and use.\22\ The rule
specifies the airspace for which Mode A/C, and S transponders are
required, and the process for when an operator may request a deviation
from the transponder requirements. Under Sec. 91.215, transponders are
required for all aircraft operating in Classes A, B, and C airspace
areas, and in all airspace at and above 10,000 feet MSL over the 48
contiguous United States and the District of Columbia. In addition,
transponders are required for operations within 30 NM of an airport
listed in 14 CFR part 91, Appendix D, from the surface upwards to
10,000 feet MSL. (The airports listed in Appendix D are in Class B
airspace areas.) \23\
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\22\ Transponder with Automatic Altitude Reporting Capability
Requirement, 53 FR 4306; February 12, 1988.
\23\ This section excludes from the transponder requirements all
aircraft not originally certificated with an electrical system or
not subsequently certified with such a system installed, such as
balloons or gliders. These operations may be conducted in the
airspace within 30 nautical miles of an airport listed in part 91
appendix D provided that the operations are conducted: (1) Outside
any Class A, Class B, or Class C airspace area; and (2) below the
altitude of the ceiling of a Class B or Class C airspace area
designated for any airport or 10,000 feet MSL, whichever is lower.
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ADS-B Out would provide for enhanced surveillance in areas where
SSR surveillance currently exists. Consequently, the FAA believes that
it is reasonable to require that aircraft meet the performance
requirements necessary for ADS-B Out for operation in airspace that
currently requires transponders. Similar to Sec. 91.215, proposed
Sec. 91.225 would require that aircraft meet ADS-B Out performance
requirements to operate in Class A, Class B, and Class C airspace
areas, and in Class E airspace areas at and above 10,000 ft MSL over
the 48 contiguous United States and the District of Columbia. In
addition, this proposal would require that aircraft meet ADS-B Out
performance requirements to operate in Class E airspace over the Gulf
of Mexico, from the coastline of the United States out to 12 NM at and
above 3,000 feet MSL. Similar to the transponder requirements, ADS-B
Out also would be required within 30 NM of an airport listed in 14 CFR
part 91, appendix D, from the surface upward to 10,000 feet MSL.
This proposal would permit aircraft not originally certificated
with an electrical system or not subsequently certified with such a
system installed (such as a balloon or glider) to conduct operations
without ADS-B Out in the airspace within 30 NM of an airport listed in
part 91 appendix D if the operations are conducted: (1) Outside any
Class B or Class C airspace area; and (2) below the altitude of the
ceiling of a Class B or Class C airspace area designated for an airport
or 10,000 feet MSL, whichever is lower.
Generally, Class A airspace is that airspace from 18,000 feet MSL
to and including FL 600, including the airspace overlying the waters
within 12 NM of the coastline of the United States. This proposal would
not require aircraft to meet the proposed ADS-B Out performance
standards for aircraft that operate in Class A airspace that extends
beyond 12 NM from the U.S. coastline and that do not enter U.S.
territorial airspace.\24\
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\24\ There are numerous Offshore Airspace Areas that are
designated as Class A airspace and the boundaries of those airspace
areas extend beyond 12 NM from the coastline of the U.S. into
international waters. Under agreement with ICAO, the U.S. provides
ATC services in these areas and may designate the airspace
accordingly in order to indicate to pilots the type of ATC services
that may be provided.
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Class B airspace is designated from the surface to 10,000 feet MSL
surrounding the nation's busiest airports in terms of airport
operations or passenger enplanements. (Class B airspace areas generally
are configured and appear as an upside down wedding cake.) The
configuration of each Class B airspace area is individually tailored
and consists of a surface area and two or more layers, and is designed
to contain all published instrument procedures. An ATC clearance is
required for all aircraft to operate in the area, and all aircraft that
are cleared receive separation services within the airspace. Under this
proposal, ADS-B Out would be required for aircraft operating in Class B
airspace areas. In addition, for those airports listed in part 91
appendix D, ADS-B Out would be required for operations within 30 NM of
the airport from the surface up to 10,000 feet MSL. This area can
experience a high volume of aircraft operations and complex transitions
from the en route environment to the terminal area around the nation's
busiest airports. Consequently, we expect ADS-B Out to result in better
surveillance across a larger area, leading to better ATC situational
awareness.
Generally, Class C airspace is designated from the surface to 4,000
feet above the airport elevation surrounding those airports that have
an operational control tower, are serviced by a radar approach control,
and have a certain number of IFR operations or passenger enplanements.
Although the configuration of each Class C area is individually
tailored, the airspace usually consists of a surface area with a 5 NM
radius and an outer circle within a 10 NM radius that extends from no
lower than 1,200 feet up to 4,000 feet above the airport elevation.
Each person must establish two-way radio communications with the ATC
facility providing air traffic services prior to entering the airspace
and must thereafter maintain those communications while within the
airspace.
Similar to the transponder requirements, we are proposing that all
[[Page 56959]]
aircraft in Class E airspace of the 48 contiguous United States and the
District of Columbia, at and above 10,000 feet MSL, meet ADS-B Out
performance requirements.
Additionally, the FAA proposes that aircraft operating in Class E
airspace over the Gulf of Mexico, from the coastline of the United
States out to 12 NM at and above 3,000 feet MSL, meet the performance
requirements for ADS-B Out. The proposed 3,000 feet MSL will be the
lowest altitude that surveillance and communication coverage will exist
for the purposes of ATC services. The rule is restricted to 12 NM from
the coastline, which is the extent of the NAS in that area.
This proposal includes an option for pilots to request an
authorization from ATC to operate in certain designated airspace with
aircraft that do not meet the ADS-B Out performance standards. As
stated previously, aircraft that do not have an electrical system, and
therefore are not ADS-B Out compliant, may receive an ATC authorization
to operate in the designated airspace. This provision would provide ATC
with the flexibility to control aircraft that may have been directed to
turn off ADS-B or to reroute non-equipped aircraft through a regulated
area if that is necessary for safety.\25\
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\25\ If the Air Traffic Controller identifies that the aircraft
avionics is not operating properly (such as providing erroneous or
incomplete information), the pilot would be instructed to turn off
the avionics. A simple switch or button in the cockpit to disable
ADS-B avionics would provide this feature. Aircraft would then be
controlled using the backup surveillance system or procedurally.
This is similar to the methods used today in removing faulty
transponder information from a controllers display. Pilots currently
have the capability to turn off transponders. Aircraft are then
handled procedurally or through primary radar returns.
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ATC authorizations may contain conditions necessary to provide a
level of safety equivalent to operation by an aircraft equipped with
ADS-B Out equipment. ATC may not be able to grant authorization in all
cases.
3. Pilot Procedures
In accordance with proper preflight actions,\26\ each operator
would have to verify ADS-B Out availability for the flight planned
route through the appropriate flight planning information sources. If
the aircraft cannot meet the proposed performance requirements using a
given position service, the operator would have to use either a
different, available position service, re-route, or reschedule the
flight. Under this proposal, pilot procedures are expected to be
minimal. Pilots would have to: (1) Check that the ADS-B avionics
equipment is turned on and operating properly; (2) ensure that message
elements (g)-(k) of part 91, appendix H, section 4 are entered during
the appropriate phase of flight; (3) turn off the ADS-B equipment if
directed by ATC; and (4) if notified by ATC that the aircraft's ADS-B
information is not being transmitted, request special handling that may
include accommodation (on a case-by-case basis), or direction to exit
the present airspace.
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\26\ See 14 CFR 91.103.
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4. Backup Surveillance Strategy
The FAA recognizes there are vulnerabilities in using a GPS system
as the aircraft's position service. There are times when GPS may be
unreliable in certain areas and during certain times due to planned
testing or solar flare activity. Unintentional interference is
historically infrequent in the U.S. In the event of GPS outages, a
backup strategy is necessary for ATC to continue surveillance
capability.
The FAA identified and analyzed several potential backup
strategies. The strategies varied from SSR, active and passive
multilateration, Distance Measuring Equipment (DME)/IRU, Satellite
Navigation (SATNAV), and combinations thereof. The FAA reviewed the
cost estimates and performance of the various combinations and
conducted comparative safety assessments. In May 2006, the
Surveillance/Positioning Backup Strategy Technical Team was formed to
review candidate strategies. The team members consisted of
representatives from air transport, general aviation, avionics
manufacturers, and the FAA's Aircraft Certification Service and Air
Traffic Organization. In addition, a steering committee was organized
under the RTCA ADS-B Working Group and the RTCA Air Traffic Management
Advisory Committee to ensure that user needs were being addressed.
The FAA specified that the backup strategy must meet certain
minimum requirements to meet the needs of the airspace users. The
strategy must be able to support ATC surveillance to at least the same
extent as current back up surveillance capabilities. In other words, at
least the same level of capacity must be maintained during a loss of
GPS signal as would be experienced during a comparative loss of radar
services today in both the terminal and en route areas over several
days.\27\
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\27\ Generally, a loss of radar services for a given area is
mitigated in one of several ways: by providing terminal capabilities
(e.g., 3 NM separations) with reduced coverage using a nearby
terminal radar; by providing en route capabilities (e.g., 5 NM
separations) with reduced coverage using the nearest en route radar;
or by reversion to procedural separation if neither of the first two
options are feasible.
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The FAA has concluded that a strategy of maintaining a reduced
network of SSRs best meets the agency's back up needs given the
limitations of ADS-B surveillance capabilities. Under this strategy,
secondary radar services will be provided in high density terminal
airspace (surrounding approximately the top 40 airports in terms of
capacity), all en route airspace above 18,000 feet MSL, and medium
density terminal airspace above certain altitudes, as determined by
proximate en route SSR coverage (identical to today's Center Radar
Automated Radar Terminal Systems Processing (CENRAP) coverage). This
approach would require retaining 40 terminal SSRs and 150 en route SSRs
beyond 2020, which is approximately one-half of the quantity in use
today. Primary surveillance radar services will be retained in all
terminal areas covered by primary radar today (approximately 200
locations), to serve as the means of mitigating single aircraft
avionics failures. No new avionics would be required to support this
strategy. The legacy transponders (Mode A/C/S) continue to support
secondary radar surveillance. A copy of the FAA's Surveillance/
Positioning Backup Strategy Alternatives Analysis Final Report, dated
December 8, 2006, has been placed in the docket for this rulemaking.
During interference outages of GNSS (scheduled or unscheduled), the
FAA expects to revert to the backup ground-based surveillance system
and temporarily allow operations without ADS-B Out in required
airspace. Pilots would be notified of such action via the Notice to
Airmen (NOTAM) system. The FAA also expects to revert to the backup
surveillance system during significant degradation in the GPS
constellation. When deciding to issue NOTAMs to allow operations by
aircraft with inoperable ADS-B Out equipment, the FAA will weigh the
impact of denying airspace access to those aircraft that do not comply
with the performance requirements against the reduction in operational
capability due to the limitations of the backup surveillance system.
5. Compliance Schedule for ADS-B Out Requirements
The FAA proposes that affected aircraft meet ADS-B Out performance
requirements by January 1, 2020. The FAA's schedule for ADS-B Out calls
for
[[Page 56960]]
the ground infrastructure, including the provision of broadcast
services, to be in place and available by the end of 2013 where
surveillance exists today. The FAA is committed to meeting this
schedule, but if unforeseen circumstances prevent ADS-B Out services
from being available by the end of 2013 where surveillance exists
today, the FAA would follow notice and comment rulemaking procedures to
adjust the compliance date. Although compliance of the rule would not
be necessary until 2020, it is necessary to have the final requirements
published to allow avionics manufacturers time to produce compliant
equipment. It is also preferable to give operators time to schedule
equipment installation consistent with the aircraft's normal
maintenance cycle. A 10-year compliance window gives the aviation
community ample time to manage costs and minimize the impact of ADS-B
installation on their normal operations.
V. ADS-B In
A. Avionics
The FAA is not proposing to mandate ADS-B In performance
requirements at this time. While ADS-B In provides substantial benefits
to operators, it has not been identified as a requirement for
maintaining the safety and efficiency of NAS operations at this time.
However, this NPRM includes a discussion of ADS-B In because ADS-B Out
transmissions provide the aircraft information viewed by the flight
crew in aircraft equipped for ADS-B In. Operators who voluntarily equip
with ADS-B In could receive additional benefits compared to those that
equip only with ADS-B Out. ADS-B In provides the capability to display
ADS-B message information to pilots in the flight deck. The ADS-B In
function is a combination broadcast link processor (i.e., it receives
information) and flight deck display.
The ADS-B Out broadcast message elements support the initial ADS-B
In applications discussed in this proposal. However, future ADS-B In
applications may require additional broadcast message elements in the
ADS-B Out transmission. The reason for the differences is that the
information displayed to ATC may be a subset of information displayed
to the pilots. Additional ADS-B Out broadcast message elements beyond
those described in this document could be needed to support a fully
functional ADS-B In CDTI for future operational applications.
Additional message elements cannot be defined until future applications
have been developed. The current set of ADS-B Out message elements will
meet the needs of the initial services and applications and the future
applications currently pursued by the FAA.
As some operators may voluntarily equip with ADS-B In avionics to
take advantage of emerging technology, the ground infrastructure will
be designed to accommodate ADS-B Out and ADS-B In. In order to provide
ADS-B In equipped aircraft with the capability to use the information
transmitted, a service called ADS-R has been developed. In this
proposal, ADS-R is considered part of the ground infrastructure that
will need to be in place to enable a fully functional ADS-B system.
ADS-R provides aircraft with a more complete traffic picture of other
ADS-B equipped aircraft using a different data-link (i.e., 1090ES
versus UAT). For example, ADS-R takes the aircraft's ADS-B information
that is transmitted by 1090ES and ``re-broadcasts'' that information to
any aircraft that is equipped for ADS-B In and uses UAT. ADS-R
similarly makes the corresponding rebroadcast of information from UAT
equipped aircraft to ADS-B In equipped aircraft using 1090ES. As stated
previously, this proposal does not seek to require ADS-B In. The FAA
does realize, however, that some operators may voluntarily equip with
ADS-B In avionics to take advantage of emerging technology. The ADS-B
ARC is investigating ways to encourage operators to equip with ADS-B
prior to the compliance date of the rule. The FAA will review the ARC's
recommendations on how to facilitate the transition between legacy
surveillance and ADS-B.
B. Applications and Services
As this proposal lays the foundation for the entire ADS-B system,
it is appropriate to briefly discuss the applications and services that
would be available with ADS-B In. Functions and associated applications
that enable an aircraft to be able to receive ADS-B messages from
ground stations and from other aircraft are collectively referred to as
ADS-B In. If aircraft are voluntarily equipped with ADS-B In, pilots
could see real-time information similar to what ATC views and have
access to similar services and applications. Pilots would have better
situational awareness because their flight deck displays would depict
all aircraft equipped with ADS-B or transponders. Pilots may be able to
use this information to monitor and maintain safe separation from other
aircraft with fewer instructions from ATC. At night and in poor visual
conditions, pilots could also see where they are in relation to the
ground using onboard avionics and terrain maps associated with a multi-
function display. The information would be clear and accurate
regardless of inclement weather conditions.
Also, like ATC, aircraft CDTIs could display precise locations of
all ADS-B equipped aircraft and ground vehicles, along with data that
shows their direction of movement in flight or on the airport surface.
With this information, pilots would be able to follow the progress of
other aircraft or ground vehicles using the cockpit display, and
correlate that position by reference to outside visual cues. The
increased position and traffic awareness would allow more efficient
movement on airport surfaces by pilots.
Aircraft equipped with ADS-B In capabilities could receive traffic
information for other aircraft regardless of whether those aircraft are
equipped with a functional ADS-B system. Aircraft equipped with ADS-B
In would also be able to identify other ADS-B equipped aircraft
regardless of the broadcast link being used. This comprehensive air
traffic situational awareness would be provided by Traffic Information
Service-Broadcast (TIS-B) until all aircraft are equipped with ADS-B
Out, at which time TIS-B would be decommissioned and the information
would be transmitted by ADS-R. Existing radar surveillance information
is provided to ground stations and sent out on both 1090ES and UAT as a
part of the TIS-B message.
The FAA expects the following two services and five applications to
be available to operators voluntarily equipping with ADS-B In:
Traffic Information Service-Broadcast (TIS-B). This is a
ground-based uplink report of traffic that is under surveillance by
ATC. During implementation of the ADS-B system, TIS-B would provide
surveillance information on aircraft that are not yet ADS-B equipped.
The ground infrastructure would support air-to-air operations by
broadcasting TIS-B messages on both the 978 MHz UAT and 1090 MHz ES
broadcast links for targets detected and reported by radar or other
surveillance systems. TIS-B would be available during the transition
period and until all affected aircraft are equipped for ADS-B Out. Once
all aircraft are equipped to meet ADS-B Out performance requirements,
TIS-B would be decommissioned as it would no longer be necessary since
aircraft would receive traffic information through ADS-B.
Flight Information Service-Broadcast (FIS-B). FIS-B
provides the
[[Page 56961]]
broadcast of weather and non-control advisory information providing
users aeronautical information supporting safe and efficient
operations. FIS-B products include, but are not limited to, graphical
and textual weather reports and forecasts, NextGen radar precipitation
information, special use airspace information, NOTAMS, electronic pilot
reports, and other similar meteorological and aeronautical information.
FIS-B products would be uplinked using the 978 MHz UAT broadcast link,
but would not be available on the 1090 MHz ES broadcast link. The FIS-B
service could accommodate additional products in the future. Both
government and commercial sources would provide uplink products.
The following applications would be available to all pilots whose
aircraft are voluntarily equipped to receive ADS-B In messages:
Airport Surface Situational Awareness. This application
would reduce the potential for deviations, errors, and collisions
through an increase in pilots' situational awareness while operating an
aircraft on the airport movement area. Pilots would use a flight deck
display to increase awareness of other traffic positions on the airport
movement area. Additionally, the display may be used to determine the
position of ground vehicles, e.g., snowplows, emergency vehicles, tugs,
follow-me vehicles, and airport maintenance vehicles, if they meet ADS-
B Out performance requirements. Surface vehicles operating on the
movement area (runways and taxiways) would need to be ADS-B Out
equipped.
Final Approach and Runway Occupancy Awareness. This
application would reduce the likelihood of pilot errors associated with
runway occupancy and would improve the capability of the flight crew to
detect ATC errors. It involves using a cockpit display to depict the
runway environment and display traffic from the surface up to
approximately 1,000 feet AGL on final approach. It would be used by the
flight crew to help determine runway occupancy.
Enhanced Visual Acquisition. This application would
provide the pilots with enhanced traffic situational awareness in
controlled and uncontrolled airspace and airports. The application uses
a cockpit display to enhance out-of-the-window visual acquisition of
air traffic. Pilots would refer to the display during the instrument
scan to supplement visual observations. The display would be used to
aid in initial detection of an aircraft or to receive further
information on an aircraft that has been reported by ATC. The
application provides the pilots with the relative range, altitude, and
bearing of other aircraft.
Enhanced Visual Approach. This application would enhance
sequential approaches for aircraft cleared to maintain visual
separation from another aircraft on the approach in order to maintain
visual approach procedure operation arrival rates even during periods
of reduced visibility or obstructions to vision (e.g., haze, fog, and
sunlight). Pilots would have a cockpit display of nearby traffic that
would continually update identity and position information to assist
the pilots with achieving and maintaining visual contact with relevant
traffic. Additional information such as range and speed would be
provided to assist pilots in monitoring their distance from the
preceding aircraft. The display may also be used to monitor aircraft on
approach to parallel runways.
Conflict Detection. This application would alert the pilot
to potential conflicts with other aircraft and provide relevant traffic
information. Aircraft equipped with a cockpit display have the
capability to display aircraft location and projected flight path. More
than simply displaying traffic, the application would alert pilots of
developing conflicts. Also, the surveillance range afforded by ADS-B
would enable alerts to be issued in time to resolve potential conflicts
with minimum disruption to the flight path. The conflict detection
application is an ADS-B-enabled capability for properly equipped
aircraft and is not intended as a TCAS replacement.
ADS-B In is not limited to the reception of these services and
applications. The ability to receive ADS-B In messages provides a
platform for services that may be developed in the future by the FAA or
by independent vendors.
Users with ADS-B In may also have greater predictability of flight
duration because they would have more information on the state of air
traffic and the procedures being used by air traffic controllers to
handle traffic. Greater predictability of arrival and departure times
could allow air carriers to have ground crews ready sooner, and with
less margin of error. Shared situational awareness may also allow
pilots to observe patterns in the flight of traffic around them and may
increase the efficiency of their flight by allowing them to operate in
concert with other traffic with less radio communication.
VI. FAA Experience With ADS-B
A. Capstone
The Capstone project was initially proposed as an operational
demonstration program for Alaska in the Bethel and Yukon-Kuskokwim (Y-
K) Delta area. Flights below 6,000 feet in the Y-K Delta are conducted
in a non-radar environment. The only radar coverage in the area is
high-altitude coverage for aircraft controlled from Anchorage.
Capstone's traffic awareness function, which lets anyone with an ADS-B
receiver see the locations and altitudes of Capstone-equipped aircraft,
enhances situational awareness to aircraft operators in the Y-K Delta.
Phase II of Capstone, which extended the Capstone program into
Southeast Alaska, officially began in March 2003. The FAA is
integrating Phase II of the Capstone program into the national ADS-B
program. Statewide deployment of ADS-B is expected to be completed by
2013.
Special Federal Aviation Regulation (SFAR) 97 allows suitably
equipped aircraft to conduct IFR Area Navigation (RNAV) operations in
Alaska on published air traffic routes using TSO-C145a/C146a navigation
systems as the only means of IFR navigation. It also allows pilots to
conduct IFR en route RNAV operations in Alaska using Special Minimum En
Route Altitudes that are outside the operational service volume of
ground-based navigation aids. This SFAR opened more than 40,000 square
miles of airspace that included more than 1,500 NM of new routes. As
discussed previously, SFAR No. 97 would remain in effect to supplement
the requirements of this proposal.
According to FAA accident statistics compiled by the MITRE
Corporation, the Capstone safety program reduced the aircraft fatal
accident rates for Alaska part 135 operators equipped with Capstone
avionics by 45%. While this accident reduction is not solely
attributable to ADS-B, the ADS-B information in the flight deck did
provide increased pilot awareness of surrounding traffic and directly
contributed to the accident rate reduction. In addition, search and
rescue efforts for individuals in equipped aircraft have been
dramatically improved over efforts towards those in non-equipped
aircraft. Knowing a more precise location of the aircraft's last known
position has minimized the response times and reduced the search area.
B. Gulf of Mexico
Air traffic across the Gulf of Mexico has experienced significant
growth over
[[Page 56962]]
the past decade, at a rate twice that of domestic airspace. The
northern portion of the Gulf of Mexico is home to one of the largest
helicopter fleets in the world. More than 650 helicopters provide
support for 5,500 off-shore oil and gas production platforms. The
helicopter fleet in the Gulf of Mexico logs approximately 2.1 million
operations per year. These operations are contained in a 500 mile area
along the Texas, Louisiana, and Mississippi coastline, extending 250
miles into the Gulf of Mexico. The majority of helicopter operations
take place between the surface and 7,000 feet. Much of this fleet flies
without the ability to communicate with or be seen by ATC, or to obtain
current weather data. When IFR conditions are prevalent, capacity is
reduced nearly 95%. On IFR days, many operators are forced to cancel
flights due to the lack of both en route and destination weather
information and surveillance. Adverse weather conditions impact the
region an average of one day out of every four.
On March 24, 2006, the National Traffic Safety Board (NTSB) issued
safety recommendations A-06-19 through 23 to the FAA in response to a
helicopter accident that occurred in the Gulf of Mexico on March 23,
2004. Specifically, the NTSB recommended, in A-06-21, that ``FAA should
ensure that the infrastructure for the National Automatic Dependent
Surveillance-Broadcast Program in the Gulf of Mexico is operational by
fiscal year 2010.''
In May 2006, the FAA established a cooperative government/industry
business relationship to enhance communications, weather, and
surveillance capabilities in the Gulf of Mexico through a Memorandum of
Agreement (MOA). Through the MOA, the FAA teamed with the Helicopter
Association International and others to deliver a higher level of
aviation service in the Gulf of Mexico. The FAA plans to build a Gulf
of Mexico infrastructure to enhance low and high altitude voice
communication and surveillance, and low altitude weather observation
capability. While chiefly intended for helicopter use, the enhancements
offer potential benefit to all aircraft operating in Gulf airspace. The
MOA continues in effect for 5 years and can be renewed. The FAA plans
to install communications equipment in the 2007/2008 timeframe, weather
equipment in the 2008 timeframe, and surveillance equipment in the
2008/2009 timeframe. The FAA expects initial operational capability of
the communications, weather, and surveillance equipment in the 2009/
2010 timeframe.
C. UPS--Louisville
The FAA and the United Parcel Service (UPS) are working together to
implement a system at Louisville, Kentucky (SDF) airport that would
increase airport capacity and efficiency while significantly reducing
vulnerability to runway incursion events and reduce the events
themselves. UPS and the FAA have developed a concept to create a system
that would use ADS-B surveillance at SDF, along with a Surface
Management System and a scheduling and sequencing system to meet the
demands of the future. ADS-B Out is expected to be operational on
certain UPS aircraft by fall 2007. UPS is also installing a CDTI
display for certain proposed operational applications such as merging
and spacing, Surface Area Moving Management, and CDTI Assisted Visual
Spacing capability in all of its B-757, B-767, B-747-400, A-300, and
MD-11 fleets.
D. Surveillance in Non-Radar Airspace
Today, there are pockets of airspace across the NAS that are
outside of radar coverage and are managed by ATC using non-radar
procedural separation. While the FAA has not yet decided whether to
place GBTs in these areas, it could decide to do so. Since the vast
majority of the fleet would already be equipped with ADS-B Out, placing
GBTs in these areas would result in the types of benefits experienced
in Alaska and predicted for the Gulf of Mexico.
Presently ATC controls IFR operations in non-radar airspace using
inefficient separation techniques and is unable to provide many
advisory services otherwise available in a surveillance environment.
Consequently, non-radar separation between aircraft in a non-radar
environment within the domestic U.S. is up to 10 minutes (80 miles for
jet traffic) compared to 3 or 5 miles in a radar environment. Operators
would realize significant efficiency gains, if ATC were able to utilize
traffic monitoring techniques currently only available in a
surveillance environment (e.g., aircraft vectoring and speed control).
Surveillance capability also allows ATC to offer other safety-
related services to both VFR and IFR aircraft, including traffic safety
alerts when aircraft that are on conflicting courses, minimum safe
altitude warnings (MSAW), and navigational assistance.
VII. ADS-B in Other Countries
The European Organisation for the Safety of Air Navigation, known
as EUROCONTROL, a cooperative organization of 37 member states in
Europe, is focused on developing a seamless, pan-European Air Traffic
Management system. In support of its objective, EUROCONTROL is
considering a plan to install ADS-B ground broadcast transceivers in
European areas that do not have adequate radar coverage. EUROCONTROL
proposed guidance is to use ADS-B for surveillance in medium density
airspace where there is currently no surveillance capability.
In April 2007, the Australian Civil Aviation Safety Authority
(CASA) published a Notice of Final Rule Making (NFRM) \28\ adopting
operational and technical standards for aircraft that are voluntarily
equipped for ADS-B services in Australian airspace. CASA stated that it
will not consider mandatory use of ADS-B until Airservices Australia
makes a final decision on the replacement of its enroute radar systems.
Until such determination is made, operators may choose to equip with
ADS-B to operate in Australian airspace. Airservices Australia is
installing ADS-B ground stations for operational use that can receive
and process both RTCA DO-260 and DO-260A transmissions to apply a 5NM
air traffic separation standard.\29\
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\28\ This NFRM summarizes the comments received in response to
proposal 0601AS and presents CASA's evaluation of those comments.
This document also sets forth the amendments for ADS-B equipage and
related guidance material.
\29\ The FAA's decision to propose performance standards that
meet TSO-166a is because the FAA intends to use ADS-B transmissions
to provide surveillance using the existing separation standards of 3
NM in terminal environments and 5 NM miles in the enroute
environment.
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NAV Canada is deploying ADS-B in northern Canada to provide
surveillance in the airspace over Hudson Bay where there currently is
no radar coverage today. Future deployments of ADS-B in Canadian
airspace are targeted for the Northwest Territories and northern B.C.,
which also do not have radar coverage. NAV Canada anticipates having
ADS-B in the rest of Canada as a replacement for, or complement to,
radar.
The FAA is working with EUROCONTROL, Airservices Australia and NAV
CANADA to internationally harmonize operational concepts and minimum
safety and performance requirements for ADS-B.
VIII. Alternatives to ADS-B
Multilateration is a non-radar system that has limited deployment
in the U.S. The FAA considered multilateration as an alternative to
ADS-B. Multilateration is a process by which an aircraft's position is
determined by measuring the time difference between the arrival of
[[Page 56963]]
the aircraft's signal to multiple receivers on the ground. At a
minimum, multilateration requires upwards of four ground stations to
deliver the same volume of coverage and integrity of information as
ADS-B, due to the need to ``triangulate'' the aircraft's position.
While both radar and multilateration meet today's surveillance needs,
it would be substantially more costly to expand these systems than to
implement ADS-B to meet future surveillance demands. Moreover, future
uses of these systems would not provide a platform for air-to-air
applications, as ADS-B does.
Radars have different update rates, accuracies, ranges, and
functions. Alternatively, since ADS-B employs one type of receiving
equipment, it does not have to accommodate for transition between
differing surveillance systems. The consistency of the signal and
information could increase the productivity of air traffic controllers
by eliminating the need to account for different surveillance systems
and environments. The deployment of secondary surveillance as a backup
would entail some of the costs, but these would be significantly less
than the costs of a full NAS-wide secondary surveillance solution.
IX. Rulemaking Notices and Analyses
Paperwork Reduction Act
This proposal contains the following new information collection
requirements. As required by the Paperwork Reduction Act of 1995 (44
U.S.C. 3507(d)), the FAA has submitted the information requirements
associated with this proposal to the Office of Management and Budget
for its review.
Title: Automatic Dependent Surveillance-Broadcast (ADS-B) Out
performance requirements to support air traffic control service.
Summary: This proposal requires performance requirements for
certain avionics equipment on aircraft operating in specified classes
of airspace within the United States National Airspace System. The
proposed rule would facilitate the use of ADS-B for aircraft
surveillance by FAA air traffic controllers to accommodate the expected
increase in demand for air transportation. In addition to accommodating
the anticipated increase in operations, this proposal, if adopted,
would provide aircraft operators with a platform for additional flight
applications and services.
Use of: This proposal would support the information needs of the
FAA by requiring avionics equipment that continuously transmits
aircraft information to be received by the FAA, via automation, for use
in providing surveillance services.
Respondents (including number of): The likely respondents to this
proposed information requirement are stated in the chart below.
Frequency: The FAA estimates that each respondent would incur costs
of installing the equipment onboard the aircraft, as provided below.
The FAA does not attribute any costs to each individual transmission
from the electronics onboard the aircraft. Attempts to capture each
aircraft transmission would be impossible and even if it could be
captured, the cost would be minimal.
Annual Burden Estimate: This proposal would result in unit aircraft
costs for new equipment installation and associated labor as follows:
ADS-B Equipment and Installation Hours & Cost & Respondents
--------------------------------------------------------------------------------------------------------------------------------------------------------
Aircraft unit costs-- Installation costs by aircraft
includes equipment and ---------------------------------------------------------------------------
installation costs Labor costs Labor hours Number of
Aircraft group --------------------------------------------------------------------------- operators
--------------------------
Low High Low High Low High
--------------------------------------------------------------------------------------------------------------------------------------------------------
GA.................................... $4,328 $17,283 $2,250................. $5,000 30.................... 50 n/a
TurboProp............................. 12,906 463,706 minimal................ 23,000 minimal............... 230 2,522
TurboJet.............................. 3,862 135,736 minimal................ 23,000 minimal............... 230 294
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: ADS-B Equipment could be hardware, software or combination of both.
The agency is soliciting comments to--
(1) Evaluate whether the proposed information requirement is
necessary for the proper performance of the functions of the agency,
including whether the information will have practical utility;
(2) Evaluate the accuracy of the agency's estimate of the burden;
(3) Enhance the quality, utility, and clarity of the information to
be collected; and
(4) Minimize the burden of collecting information on those who are
to respond, including by using appropriate automated, electronic,
mechanical, or other technological collection techniques or other forms
of information technology. Individuals and organizations may send
comments on the information collection requirement by January 3, 2008,
and should direct them to the address listed in the Addresses section
at the end of this preamble. Comments also should be faxed to the
Office of Information and Regulatory Affairs, OMB, (202) 395-6974,
Attention: Desk Officer for FAA.
According to the 1995 amendments to the Paperwork Reduction Act (5
CFR 1320.8(b)(2)(vi)), an agency may not collect or sponsor the
collection of information, nor may it impose an information collection
requirement unless it displays a currently valid OMB control number.
The OMB control number for this information collection will be
published in the Federal Register after the Office of Management and
Budget approves it.
International Compatibility
In keeping with U.S. obligations under the Convention on
International Civil Aviation, it is FAA policy to comply with ICAO
SARPS to the maximum extent practicable. Considering that the long-term
global capabilities of ADS-B are not yet fully defined, ICAO SARPS are
still evolving and are not yet fully developed. However, the FAA
researched existing ICAO requirements for ADS-B Out operations (using
one of the ADS-B links, either 1090ES or UAT) to the maximum extent
practicable. Specifically, the FAA reviewed applications to avionics
and airframe manufacturers, air carriers, and general aviation
operating under 14 CFR parts 91, 121, 125, or 135, and foreign air
carriers conducting operations in U.S. airspace. The FAA has identified
no differences with these proposed regulations.\30\
[[Page 56964]]
Regulatory Evaluation, Regulatory Flexibility Determination,
International Trade Impact Assessment, and Unfunded Mandates Assessment
Changes to Federal regulations must undergo several economic
analyses. First, Executive Order 12866 directs that each Federal agency
shall propose or adopt a regulation only upon a reasoned determination
that the benefits of the intended regulation justify its costs. Second,
the Regulatory Flexibility Act of 1980 (Pub. L. 96-354) requires
agencies to analyze the economic impact of regulatory changes on small
entities. Third, the Trade Agreements Act (Pub. L. 96-39) prohibits
agencies from setting standards that create unnecessary obstacles to
the foreign commerce of the United States. In developing U.S.
standards, this Trade Act requires agencies to consider international
standards and, where appropriate, that they be the basis of U.S.
standards. Fourth, the Unfunded Mandates Reform Act of 1995 (Pub. L.
104-4) requires agencies to prepare a written assessment of the costs,
benefits, and other effects of proposed or final rules that include a
Federal mandate likely to result in the expenditure by State, local, or
tribal governments, in the aggregate, or by the private sector, of $100
million or more annually (adjusted for inflation with base year of
1995). This portion of the preamble summarizes the FAA's analysis of
the economic impacts of this proposed rule. We suggest readers seeking
greater detail read the full regulatory impact analysis, a copy of
which we have placed in the docket for this rulemaking.
In conducting these analyses, FAA has determined that this proposed
rule: (1) Has benefits that justify its costs, (2) is an economically
``significant regulatory action'' as defined in section 3(f) of
Executive Order 12866, (3) is ``significant'' as defined in DOT's
Regulatory Policies and Procedures; (4) would have a significant
economic impact on a substantial number of small entities; (5) would
not create unnecessary obstacles to the foreign commerce of the United
States; and (6) would impose an unfunded mandate on state, local, or
tribal governments, or on the private sector by exceeding the threshold
identified above. These analyses are summarized below.
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\30\ ICAO references: PANS-ATM, Doc 4444, Amendment 4 (24/11/
05), Procedures for Air Navigation Services--Air Traffic Management;
Doc 9694, ICAO Manual of Air Traffic Services Data Link
Applications; Annex 2, Rules of the Air; Annex 4, Aeronautical
Charts; Annex 6 Part II, Operation of Aircraft; Annex 11, Air
Traffic Services; Annex 15, Aeronautical Information Services; Doc
9689, Manual for determination of separation minima; Circular 311,
SASP Circular--ADS-B Comparative Assessment; Circular 278, National
Plan for CNS/ATM Systems Guidance Material; Annex 10 Vol. IV,
Amendment 77, Aeronautical Telecommunications; Doc 9871, Technical
Provisions for Mode S Services and Extended Squitter (Approved draft
to be published in 2006); Doc 9688, ICAO Manual on Mode S Specific
Services.
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Request for Comment
While we welcome and encourage, all comments on the regulatory
evaluation, we specifically request comment in the regulatory
evaluation as follows:
We solicit comments from manufacturers of large category
turbojet, regional turboprop and general aviation aircraft on when they
intend to start delivering new aircraft to comply with the rule if
enacted. We need clarification of the avionics currently installed on
new production airplanes and expected enhancements that would occur
without the rule. Lastly, we solicit comment regarding the remaining
assumptions.
We assumed the weight for an ADS-B Out transponder, on a
GA aircraft, would be about the same as weight as existing transponders
and therefore the change would be negligible and there would be no
additional weight or fuel burn costs. We request comments from industry
on this assumption.
We request comments from industry on the estimated costs,
maintenance intervals MTBF replacement, and MTTR requirements for the
ADS-B Out transponder and position source units.
The FAA solicits comments on the benefits that we have
identified and estimated and whether there are any potential benefits
of ADS-B that we have not identified.
We solicit comments from the industry on what they expect
avionics costs of equipping with ADS-B In to be as well as whether the
industry will voluntarily equip and the benefits of ADS-B In equipage.
We request comments from the aviation industry about FAA
surveillance deployment strategies that could permit acceleration of
realized benefits.
The FAA seeks comment, with supportive justification, to
determine the degree of hardship the proposed rule will have on these
small entities.
Overall, in terms of competition, this rulemaking reduces
small operators ability to compete. We request comments from industry
on the results of the competitive analysis.
The FAA assumed that maintenance and replacement costs for
ADS-B Out for GA aircraft equals zero because the maintenance and
replacement times would occur beyond 2035. The FAA seeks comment on
this assumption.
Total Benefits and Costs of this Rule
The demand for air travel is growing in the U.S. and around the
world. The FAA's forecasts project a doubling in U.S. airline passenger
traffic by 2025. The forecasts also show strong growth for general
aviation, especially with the advent of very light jets.
The solution to managing the anticipated growth in the use of the
NAS is the Next Generation Air Transportation System, or NextGen, which
will assure the safe and efficient movement of people and goods as
demand increases. NextGen will use technology to allow precise
navigation, permit accurate real-time communication, and vastly improve
situational awareness.
ADS-B is the chosen new technology for surveillance in the NextGen
system. It is a key component in achieving many of the goals set forth
in the Next Generation Air Transportation System (NextGen) Integrated
Plan.
We review the following three alternatives for surveillance in this
analysis:
1. Baseline radar--maintain the current radar based surveillance
system and replace radar facilities when they wear out;
2. ADS-B--Aircraft operators equip to meet performance requirements
proposed by the rule and the FAA provides surveillance services based
on downlinked aircraft information.
3. Multilateration--The FAA would provide surveillance using
multilateration.
The proposed rule requires aircraft to equip only with ADS-B Out
when flying in certain airspace. Operators may choose to more fully
equip with ADS-B In and Out, and so we also address these costs and
benefits.
The estimated cost of this proposed rule ranges from a low of $2.3
billion ($1.6 billion at 7% present value) to a high of $8.5 billion
dollars ($4.5 billion at 7% present value).\31\ These costs include
costs to the government, as well as to the aviation industry and other
users of the airspace, to deploy ADS-B and are incremental to
maintaining surveillance via current technology (radar). The aviation
industry would begin incurring costs for avionics equipage in 2012 and
would incur total costs ranging from $1.27 billion ($670 million at 7%
present value) \32\ to $7.46 billion ($3.6 billion at 7% present value)
\33\ with an estimated midpoint of
[[Page 56965]]
$4.32 billion ($2.12 billion at 7% present value) \34\ from 2012 to
2035.
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\31\ Costs at 3% present value range from $1.9 billion to $6.3
billion.
\32\ $950 million at 3% present value.
\33\ $5.35 billion at 3% present value.
\34\ $3.13 billion at 3% present value.
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The estimated quantified potential benefits of the proposed rule
are about $10 billion ($2.7 billion at 7% present value) \35\ and
primarily result from fuel, operating cost and time savings from more
efficient flights.
---------------------------------------------------------------------------
\35\ $5.48 billion at 3% present value.
---------------------------------------------------------------------------
The proposed rule would make it more likely that aircraft operators
would equip with ADS-B In equipment, which could result in estimated
additional benefits of $3.9 billion ($1.0 billion at 7% present
value).\36\ The additional cost of the ADS-B In ground segment is
estimated at $533 million ($283 million at 7% present value).\37\ We
did not estimate the cost for aircraft operators to equip with ADS-B In
because we concluded the requirements for ADS-B In are insufficient in
detail and do not yet support the development of a cost estimate. The
FAA will continue to study ADS-B In technology and intends to provide
an adoption cost estimate for the final rule. Benefits of both ADS-B In
and Out have been estimated at $13.8 billion ($3.7 billion at 7%
present value).\38\ Estimated costs of ADS-B In and Out (excluding ADS-
B In avionics costs), relative to the radar baseline, range from $2.8
billion ($1.8 at 7% present value) \39\ to $9.0 billion ($4.8 at 7%
present value).\40\
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\36\ $2.1 billion at 3% present value.
\37\ $392 million when discounted by 3%.
\38\ $7.6 billion at 3% present value.
\39\ $2.3 billion at 3% present value.
\40\ $6.7 billion at 3% present value.
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While we do not have estimates of ADS-B In avionics costs, we can
derive an upper bound for what that cost cannot exceed if the ADS-B In
and Out scenario is to be cost beneficial relative to radar for each of
the two possibilities described below.
Given that we have a range of costs (low to high) we considered two
possibilities: (1) Low cost, and (2) high cost:
We concluded that ADS-B In and Out would be cost
beneficial at a present value of 7% if the costs for the ADS-B Out
avionics are low ($670 million at 7% present value) and the avionics
costs for ADS-B In do not exceed $1.85 billion at 7% present value.
We also concluded that ADS-B In and Out would be cost
beneficial at a 3% present value if the costs for the ADS-B Out
avionics are low ($950 million at 3% present value) and the ADS-B In
avionics costs do not exceed $5.3 billion at 3% present value or if the
costs for the ADS-B Out avionics are high ($5.35 billion at 3% present
value) and the ADS-B In avionics costs do not exceed $870 million.
ADS-B is a critical component of the Next Generation Air
Transportation System Plan (NextGen) that is being developed to
transform today's radar-based aviation system to handle increased
aviation demand. By itself, ADS-B presents significant benefits, but as
a component of the NextGen system the benefits will substantially
increase. The Draft Regulatory Impact Analysis has been placed in the
docket for this rulemaking.
Reduced Carbon Dioxide Emissions
Besides the cost savings made possible by this proposed rulemaking,
there will also be potential environmental benefits. ADS-B is an
enabling technology critical to the concept of operations for the Next
Generation Air Transportation System (NextGen) plan. Under the NextGen
operational concept there will be less fuel used on many flights
because of fewer potential conflicts needing resolution, more efficient
en route conflict resolution aircraft maneuvers, and more efficient
taxi and ground idle operations. Additionally, having more precise
knowledge of the position of an aircraft with ADS-B may assist the
implementation of such environmentally friendly flight procedures like
continuous descent arrivals (CDA) to be employed in higher density
traffic times.
The FAA estimates that between 2017 and 2035 ADS-B technology would
allow more efficient handling of potential en route conflicts, which
will result in a total of 410 million gallons of fuel savings in the
national airspace system over that time period. This decrease in fuel
use would result in about 4 million metric tons less carbon dioxide
emissions.\41\ The increased use of continuous descent approaches that
ADS-B would allow would lead to about 10 billion pounds of total fuel
savings from 2017 through 2035. This would result in about 14 million
tons less carbon dioxide emissions. Additionally, the FAA has estimated
a decline in fuel use on airline flights over the Gulf of Mexico due to
optimal routing because of this proposed rulemaking. This savings in
fuel use would result in an additional cumulative decrease of 300,000
metric tons of carbon dioxide emissions over the 2012 to 2035 time
period.
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\41\ For more information on the methodology used to calculate
this estimate, see ``ADS-B Benefits Enabled from Improved en Route
Conflict Probe Performance'' in the docket established for this
rulemaking. The specific data in this regulatory evaluation however,
is more conservation than the data in the report just mentioned.
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Reduced fuel consumption will also translate into fewer emissions
such as oxides of nitrogen, which potentially impact, both local air
quality and climate (as a greenhouse gas emission), as well as
hydrocarbons and carbon monoxide-both of which impact local air
quality. Reduction in local air quality impacts associated with
increasing capacity is vital in maintaining compliance with national
ambient air quality standards.
The FAA solicits comments on the benefits that we have identified
and estimated and whether there are any potential benefits of ADS-B
that we have not identified.
Initial Regulatory Flexibility Determination ADS-B
Introduction and Purpose of This Analysis
The Regulatory Flexibility Act of 1980 (Pub. L. 96-354) (RFA)
establishes ``as a principle of regulatory issuance that agencies shall
endeavor, consistent with the objectives of the rule and of applicable
statutes, to fit regulatory and informational requirements to the scale
of the businesses, organizations, and governmental jurisdictions
subject to regulation. To achieve this principle, agencies are required
to solicit and consider flexible regulatory proposals and to explain
the rationale for their actions to assure that such proposals are given
serious consideration.'' The RFA covers a wide-range of small entities,
including small businesses, not-for-profit organizations, and small
governmental jurisdictions.
Agencies must perform a review to determine whether a rule will
have a significant economic impact on a substantial number of small
entities. If the agency determines that it will, the agency must
prepare a regulatory flexibility analysis as described in the RFA.
However, if an agency determines that a proposed or final rule is
not expected to have a significant economic impact on a substantial
number of small entities, section 605(b) of the 1980 RFA provides that
the head of the agency may so certify and a regulatory flexibility
analysis is not required. The certification must include a statement
providing the factual basis for this determination, and the reasoning
should be clear.
The FAA believes that this proposal would result in a significant
economic impact on a substantial number of small entities. The purpose
of this analysis is
[[Page 56966]]
to provide the reasoning underlying the FAA determination.
Under Section 603(b) of the RFA, the analysis must address:
Description of reasons the agency is considering the
action,
Statement of the legal basis and objectives for the
proposed rule,
Description of the record keeping and other compliance
requirements of the proposed rule,
All federal rules that may duplicate, overlap, or conflict
with the proposed rule,
Description and an estimated number of small entities to
which the proposed rule will apply,
Analysis of small firms' ability to afford the proposed
rule,
Estimation of the potential for business closures,
Conduct a competitive analysis,
Conduct a disproportionality analysis, and
Describe the alternatives considered.
Reasons Why the Rule Is Being Proposed
Public Law 108-176, referred to as ``The Century of Aviation
Reauthorization Act,'' was enacted December 12, 2003 (Pub. L. 108-176).
This law set forth requirements and objectives for transforming the air
transportation system to progress further into the 21st century.
Section 709 of this statute requires the Secretary of Transportation to
establish in the FAA a joint planning and development office (JPDO) to
manage work related to the Next Generation Air Transportation System
(NextGen). Among its statutorily defined responsibilities, the JPDO
coordinates the development and utilization of new technologies to
ensure that when available, they may be used to the fullest potential
in aircraft and in the air traffic control system.
The FAA, the National Aeronautics and Space Administration (NASA)
and the Departments of Commerce, Defense, and Homeland Security have
launched an effort to align their resources to develop and further the
NextGen. The goals of NextGen, as stated in section 709, are addressed
by this proposal and include:
(1) Improve the level of safety, security, efficiency, quality, and
affordability of the NAS and aviation services;
(2) take advantage of data from emerging ground-based and space-
based communications, navigation, and surveillance technologies;
(3) be scalable to accommodate and encourage substantial growth in
domestic and international transportation and anticipating and
accommodating continuing technology upgrades and advances; and
(4) accommodate a wide range of aircraft operations, including
airlines, air taxis, helicopters, general aviation, and unmanned aerial
vehicles.
The JPDO was also charged to create and carry out an integrated
plan for NextGen. The NextGen Integrated Plan,\42\ transmitted to
Congress on December 12, 2004, ensures that the NextGen system meets
the air transportation safety, security, mobility, efficiency and
capacity needs beyond those currently included in the FAA's Operational
Evolution Plan (OEP). As described in the NextGen Integrated Plan, the
current approach to air transportation, i.e., ground based radars
tracking congested flyways and passing information among the control
centers for the duration of the flights, is becoming operationally
obsolete. The current system is increasingly inefficient and large
increases in air traffic will only result in mounting delays or
limitations in service for many areas.
---------------------------------------------------------------------------
\42\ A copy of the Plan has been placed in the docket for this
rulemaking.
---------------------------------------------------------------------------
This growth will result in more air traffic than the present system
can handle. The current method of handling traffic flow will not be
able to adapt to the highest volume and density of it in the future. It
is not only the number of flights but also the nature of the new growth
that is problematic, as the future of aviation will be much more
diverse than it is today. For example, a shift of 2 percent of today's
commercial passengers to micro-jets that seat 4-6 passengers would
result in triple the number of flights in order to carry the same
number of passengers. Furthermore, the challenges grow as other non-
conventional aircraft, such as unmanned aircraft, are developed for
special operations, e.g. forest fire fighting.
The FAA believes that ADS-B technology is a key component in
achieving many of the goals set forth in the plan. This proposed rule
embraces a new approach to surveillance that can lead to greater and
more efficient utilization of airspace. The NextGen Integrated Plan
articulates several large transformation strategies in its roadmap to
successfully creating the Next Generation System. This proposal is a
major step toward strategically ``establishing an agile air traffic
system that accommodates future requirements and readily responds to
shifts in demand from all users.'' ADS-B technology would assist in the
transition to a system with less dependence on ground infrastructure
and facilities, and provide for more efficient use of airspace.
Statement of the Legal Basis and Objectives
The FAA's authority to issue rules regarding aviation safety is
found in Title 49 of the United States Code. Subtitle I, Section 106
describes the authority of the FAA Administrator. Subtitle VII,
Aviation Programs, describes in more detail the scope of the agency's
authority.
This rulemaking is promulgated under the authority described in
Subtitle VII, Part A, Subpart I, Section 40103, Sovereignty and use of
airspace, and Subpart III, section 44701, General requirements. Under
section 40103, the FAA is charged with prescribing regulations on the
flight of aircraft, including regulations on safe altitudes,
navigating, protecting, and identifying aircraft, and the safe and
efficient use of the navigable airspace. Under section 44701, the FAA
is charged with promoting safe flight of civil aircraft in air commerce
by prescribing regulations for practices, methods, and procedures the
Administrator finds necessary for safety in air commerce.
This proposal is within the scope of sections 40103 and 44701 since
it proposes aircraft performance requirements that would meet advanced
surveillance needs to accommodate the projected increase in operations
within the National Airspace System (NAS). As more aircraft operate
within the U.S. airspace, improved surveillance performance is
necessary to continue to balance the growth in air transportation with
the agency's mandate for a safe and efficient air transportation
system.
Projected Reporting, Recordkeeping and Other Requirements
We expect no more than minimal new reporting and recordkeeping
compliance requirements to result from this proposed rule. Costs for
the initial installation of new equipment and associated labor
constitute a burden under the Paperwork Reduction Act and are accounted
for in this document.
Overlapping, Duplicative, or Conflicting Federal Rules
We are unaware that the proposed rule will overlap, duplicate or
conflict with existing Federal Rules.
Estimated Number of Small Firms Potentially Impacted
Under the RFA, the FAA must determine whether a proposed rule
significantly affects a substantial
[[Page 56967]]
number of small entities. This determination is typically based on
small entity size and cost thresholds that vary depending on the
affected industry. Using the size standards from the Small Business
Administration for Air Transportation and Aircraft Manufacturing, we
defined companies as small entities if they have fewer than 1,500
employees.\43\
---------------------------------------------------------------------------
\43\ 13 CFR part 121.201, Size Standards Used to Define Small
Business Concerns, Sector 48-49 Transportation, Subsector 481 Air
Transportation.
---------------------------------------------------------------------------
We considered the economic impact on small-business part 91, 121,
and 135 operators. Many of the General Aviation (GA) aircraft are
operating in part 91 are not for hire or flown for profit so we will
not include these operators in our small business impact analysis.
This proposed rule would become final in 2009 and fully effective
in 2020. Although the FAA forecasts traffic and air carrier fleets to
2030, our forecasts do not have the granularity to determine if an
operator will still be in business or will still remain a small
business entity. Therefore we will use current U.S. operator's fleet
and employment in order to determine the number of operators this
proposal would affect.
We obtained a list of part 91, 121 and 135 U.S. operators from the
FAA Flight Standards Service.\44\ Using information provided by the
U.S. Department of Transportation Form 41 filings, World Aviation
Directory and ReferenceUSA, operators that are subsidiary businesses of
larger businesses and businesses with more than 1,500 employees were
eliminated from the list of small entities. In many cases the
employment and annual revenue data was not public and we did not
include these companies in our analysis. For the remaining businesses,
we obtained company revenue and employment from the above three
sources.
---------------------------------------------------------------------------
\44\ AFS-260.
---------------------------------------------------------------------------
The methodology discussed above resulted in the following list of
34 U.S. part 91, 121 and 135 operators, with less than 1,500 employees,
who operate 341 airplanes. Due to the sparse amount of publicly
available data on internal company financial statistics for small
entities, it is not feasible to estimate the total population of small
entities affected by this proposed rule. These 34 U.S. small entity
operators are a representative sample to assess the cost impact of the
total population of small businesses, who operate aircraft affected by
this proposed rulemaking.
------------------------------------------------------------------------
Number of
Operator name aircraft
------------------------------------------------------------------------
Air 1ST Aviation Companies of Oklahoma, Inc.................. 9
Air Flight Enterprises Inc................................... 2
Air Transport International.................................. 12
Aircraft Charter Services Inc................................ 2
Allegiant Air................................................ 26
American Check Transport Inc................................. 11
Anaconda Aviation Corp....................................... 2
Arrow Services............................................... 2
Bankair Inc.................................................. 10
Caribbean Sun Airlines....................................... 6
Champion Air................................................. 16
Copper Station Holdings, LLC................................. 1
EPPS Air Service, Inc........................................ 11
ERA Aviation Inc............................................. 9
Executive Airlines........................................... 38
Falcon Air Express........................................... 4
GOJET Airlines............................................... 15
Lynden Air Cargo............................................. 6
Miami Air International...................................... 11
Midwest Airlines............................................. 36
North American Airlines...................................... 9
Northeast Aviation, Inc...................................... 1
Northern Air Cargo........................................... 10
Omni Air International....................................... 16
Pace Airlines................................................ 8
Premier Jets Inc............................................. 1
Professional Aviation Services............................... 4
Royal Air Freight, Inc....................................... 3
Ryan International Airlines.................................. 12
Samaritan's Purse............................................ 2
Sun Country Airlines......................................... 13
USA Jet Airlines............................................. 10
World Airways................................................ 17
XTRA Airways................................................. 6
----------
Total.................................................... 341
------------------------------------------------------------------------
Cost and Affordability for Small Entities
To assess the cost impact to small business part 91, 121 and 135
operators, we contacted manufacturers, industry associations, and ADS-B
equipage providers to estimate ADS-B equipage costs. We requested
estimates of airborne installation costs, by aircraft model, for the
output parameters listed in the Equipment Specifications section of the
Regulatory Evaluation.
This proposed rule would become final in 2009 and fully effective
in 2020. Although the FAA forecast traffic and air carrier fleets to
2030, our forecasts do not have the granularity to determine if an
operator will still be in business or will still remain a small
business entity. Therefore we will use current U.S. operator's revenues
and apply the industry-provided costs in order to determine if this
proposal would have a significant impact on a substantial number of
small entity operators.
To satisfy the manufacturer's request to keep individual aircraft
pricing confidential, we calculated a low, baseline, and high range of
costs by equipment class. The baseline estimate equals the average of
the low and high industry estimates. The dollar value ranges consist of
a wide variety of avionics within each aircraft group. The aircraft
architecture within each equipment group can vary, causing different
carriage, labor and wiring requirements for the installation of ADS-B.
Volume discounting versus single line purchasing also affects the
dollar value ranges. On the low end, the dollar value may represent a
software upgrade or OEM option change. On the high end, the dollar
value may represent a new installation of upgraded transponder systems
necessary to assure accuracy, reliability and safety. We used the
estimated baseline dollar value cost by equipment class in determining
the impact to small business entities.
We estimated each operator's total compliance cost by multiplying
the baseline dollar value cost, by equipment class, by the number of
aircraft each small business operator currently has in its fleet. We
summed these costs by equipment class and group. We then measured the
economic impact on small entities by dividing the estimated baseline
dollar value compliance cost for their fleet by the small entity's
annual revenue. Each equipment group operated by a small entity may
have to comply with different requirements in the proposed rule
depending on the state the aircraft's avionics. In the ADS-B Out
Equipage Cost Estimate section of the Regulatory Evaluation we detail
our methodology to estimate operator's total compliance cost by
equipment group.
As shown in the following table, the ADS-B cost is estimated to be
greater than two percent of annual revenues for 12 small entity
operators and greater than one percent of annual revenues for 19 small
entity operators.
BILLING CODE 4910-13-P
[[Page 56968]]
[GRAPHIC] [TIFF OMITTED] TP05OC07.008
BILLING CODE 4910-13-C
Thus, from this sample population, the FAA determined that a
substantial number of small entities would be significantly affected by
the proposed rule. Every small entity who operates an aircraft in the
airspace defined by this proposal would be required to install ADS-B
out equipage and therefore would be affected by this rulemaking.
Business Closure Analysis
For commercial operators, the ratio of present-value costs to
annual revenue shows that 7 of 34 small business air operator firms
analyzed would have rations in excess of five percent. Since many of
the other commercial small business air operator firms do not make
their annual revenue publicly available, it is difficult to assess the
financial impact of this proposed rule on their business. To fully
assess whether this proposed rule could force a small entity into
bankruptcy requires more financial information than is publicly
available.
The FAA seeks comment, with supportive justification, to determine
the degree of hardship, and feasible alternative methods of compliance,
the proposed rule will have on these small entities.
[[Page 56969]]
Competitive Analysis
The aviation industry is an extremely competitive industry with
slim profit margins. The number of operators who entered the industry
and have stopped operations because of mergers, acquisitions, or
bankruptcy litters the history of the aviation industry.
The FAA analyzed five years of operating profits for the affected
small-entity operators listed above. We were able to determine the
operating profit for 18 of the 34 small business entities. The FAA
discovered that 33% of these 18 affected operator's average operating
profit is negative. Only four of the 18 affected operators had average
annual operating profit that exceeded $10,000,000. These results are
shown in the following table.
[GRAPHIC] [TIFF OMITTED] TP05OC07.009
In this competitive industry, cost increases imposed by this
proposed regulation would be hard to recover by raising prices,
especially by those operators showing an average five-year negative
operating profit. Further, large operators may be able to negotiate
better pricing from outside firms for inspections and repairs, so small
operators may need to raise their prices more than large operators.
These factors make it difficult for the small operators to recover
their compliance costs by raising prices. If small operators cannot
recover all the additional costs imposed by this regulation, market
shares could shift to the large operators.
Small operators successfully compete in the aviation industry by
providing unique services and controlling costs. To the extent the
affected small entities operate in niche markets enhances small
entity's ability to pass on costs. Currently small operators are much
more profitable than the established major scheduled carriers. This
proposed rule would offset some of the advantages of older aircraft
lower capital cost.
Overall, in terms of competition, this rulemaking reduces small
operators ability to compete. We request comments from industry on the
results of the competitive analysis.
Disproportionality Analysis
The disproportionately higher impact of the proposed rule on the
fleets of small operators result in disproportionately higher costs to
small operators. Due to the potential of fleet discounts, large
operators may be able to negotiate better pricing from outside sources
for inspections, installation, and ADS-B hardware purchases. Based on
the percent of potentially affected current airplanes over the analysis
period, small U.S. business operators may bear a disproportionate
impact from the proposed rule.
Comments received and final rule changes on regulatory flexibility
issues will be addressed in the statement of considerations for the
final rule.
Analysis of Alternatives
Alternative One
The status quo alternative has compliance costs to continue the
operation and commissioning of radar sites. The FAA rejected this
status quo alternative because the ground based radars tracking
congested flyways and passing information among the control centers for
the duration of the flights is becoming operationally obsolete. The
current system is not efficient enough to accommodate the estimated
increases in air traffic, which would result in mounting delays or
limitations in service for many areas.
Alternative Two
This alternative would employ a technology called multilateration.
Multilateration is a separate type of secondary surveillance system
that is not radar and has limited deployment in the U.S. At a minimum,
multilateration requires upwards of four ground stations to deliver the
same volume of coverage and integrity of information as ADS-B, due to
the need to ``triangulate'' the aircraft's position. Multilateration is
a process wherein an aircraft position is determined using the
difference in time of arrival of a signal from an aircraft at a series
of receivers on the ground. Multilateration meets the need for accurate
surveillance and is less costly than ADS-B (but more costly than
radar), but cannot achieve the same level of benefits that ADS-B can.
Multilateration would provide the same benefits as radar, but at a
higher cost.
Alternative Three
This alternative would provide relief by having the FAA provide an
exemption to small air carriers from all requirements of this rule.
This alternative would mean that the small air carriers would rely on
the status quo ground based radars tracking their flights and passing
information among the control centers for the duration of the flights.
This alternative would require compliance costs to continue for
[[Page 56970]]
the commissioning of radar sites. Air traffic controller workload and
training costs would increase having to employ two systems in tracking
aircraft. Small entities may request ATC deviations prior to operating
in the airspace affected by this proposal. It would also be contrary to
our policy for one level of safety in part 121 operations to exclude
certain operators simply because they are small entities. Thus, this
alternative is not considered to be acceptable.
Alternative Four
This alternative is the proposed ADS-B rule. ADS-B does not employ
different classes of receiving equipment or provide different
information based on its location. Therefore, controllers will not have
to account for transitions between surveillance solutions as an
aircraft moves closer or farther away from an airport. In order to meet
future demand for air travel without significant delays or denial of
service, ADS-B was found to be the most cost effective solution to
maintain a viable air transportation system. ADS-B provides a wider
range of services to aircraft users and could enable applications
unavailable to multilateration or radar.
Trade Impact Assessment
The Trade Agreements Act of 1979 (Pub. L. 96-39) prohibits Federal
agencies from establishing any standards or engaging in related
activities that create unnecessary obstacles to the foreign commerce of
the United States. Legitimate domestic objectives, such as safety, are
not considered unnecessary obstacles. The statute also requires
consideration of international standards and, where appropriate, that
they be the basis for U.S. standards.
ICAO is developing a set of standards that are influenced by, and
similar to, the U.S. RTCA developed standards. Initial discussions with
the international community lead us to conclude that U.S. aircraft
operating in foreign airspace would not have to add any equipment or
incur any costs in addition to what they would incur to operate in
domestic airspace under this proposed rulemaking. Foreign operators may
incur additional costs to operate in U.S. airspace, if their national
rules, standards and, current level of equipage are different than
those required by this proposed rule. The FAA is actively engaged with
the international community to ensure that the international and US.
ADS-B standards are as compatible as possible. For a fuller discussion
of what other countries are planning with regard to ADS-B, see Section
VII of this preamble. By 2020 ICAO standards may change to harmonize
with this proposed rule and foreign operators will not have to incur
additional costs.
Unfunded Mandates Assessment
Title II of the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-
4) requires each Federal agency to prepare a written statement
assessing the effects of any Federal mandate in a proposed or final
agency rule that may result in an expenditure of $100 million or more
(adjusted annually for inflation with the base year 1995) in any one
year by State, local, and tribal governments, in the aggregate, or by
the private sector; such a mandate is deemed to be a ``significant
regulatory action.'' The FAA currently uses an inflation-adjusted value
of $128.1 million in lieu of $100 million. This proposed rule is not
expected to impose significant costs on small governmental
jurisdictions such as state, local, or tribal governments, but the FAA
calls for comment on whether this expectation is correct. However, this
proposed rule would result in an unfunded mandate because it would
result in expenditures in excess of an inflation-adjusted value of
$128.1 million. We have considered three alternatives to this
rulemaking, which are discussed in section 4.0 and in the regulatory
flexibility analysis in section 7.
Executive Order 13132, Federalism
The FAA has analyzed this proposed rule under the principles and
criteria of Executive Order 13132, Federalism. We determined that this
action would not have a substantial direct effect on the States, on the
relationship between the national Government and the States, or on the
distribution of power and responsibilities among the various levels of
government, and therefore would not have federalism implications.
Environmental Analysis
FAA Order 1050.1E identifies FAA actions that are categorically
excluded from preparation of an environmental assessment or
environmental impact statement under the National Environmental Policy
Act in the absence of extraordinary circumstances. The FAA has
determined this proposed rulemaking action qualifies for the
categorical exclusion identified in paragraph 312f and involves no
extraordinary circumstances.
Regulations That Significantly Affect Energy Supply, Distribution, or
Use
The FAA has analyzed this NPRM under Executive Order 13211, Actions
Concerning Regulations that Significantly Affect Energy Supply,
Distribution, or Use (May 18, 2001). We have determined that it is not
a ``significant energy action'' under the executive order because it is
not a ``significant regulatory action'' under Executive Order 12866,
and it is not likely to have a significant adverse effect on the
supply, distribution, or use of energy.
List of Subjects in 14 CFR Part 91
Aircraft, Airmen, Air traffic control, Aviation safety, Reporting
and recordkeeping requirements.
The Proposed Amendment
In consideration of the foregoing, the Federal Aviation
Administration proposes to amend chapter I of title 14, Code of Federal
Regulations, as follows:
PART 91--GENERAL OPERATING AND FLIGHT RULES
1. The authority citation for part 91 continues to read as follows:
Authority: 49 U.S.C. 106(g), 1155, 40103, 40113, 40120, 44101,
44111, 44701, 44709, 44711, 44712, 44715, 44716, 44717, 44722,
46306, 46315, 46316, 46504, 46506-46507, 47122, 47508, 47528-47531,
articles 12 and 29 of the Convention on International Civil Aviation
(61 stat.1180).
2. Amend Sec. 91.1 by revising paragraph (b) to read as follows:
Sec. 91.1 Applicability.
* * * * *
(b) Each person operating an aircraft in the airspace overlying the
waters between 3 and 12 nautical miles from the coast of the United
States must comply with Sec. Sec. 91.1 through 91.21; Sec. Sec.
91.101 through 91.143; Sec. Sec. 91.151 through 91.159; Sec. Sec.
91.167 through 91.193; Sec. 91.203; Sec. 91.205; Sec. Sec. 91.209
through 91.217; Sec. 91.221, Sec. 91.225; Sec. Sec. 91.303 through
91.319; Sec. Sec. 91.323 through 91.327; Sec. 91.605; Sec. 91.609;
Sec. Sec. 91.703 through 91.715; and Sec. 91.903.
* * * * *
3. Revise Sec. 91.217 to read as follows:
Sec. 91.217 Data correspondence between automatically reported
pressure altitude data and the pilot's altitude reference.
(a) No person may operate any automatic pressure altitude reporting
equipment associated with a radar beacon transponder--
(1) When deactivation of that equipment is directed by ATC;
(2) Unless, as installed, that equipment was tested and calibrated
to transmit altitude data corresponding within 125 feet (on a 95
percent probability basis) of the indicated or calibrated datum of the
altimeter
[[Page 56971]]
normally used to maintain flight altitude, with that altimeter
referenced to 29.92 inches of mercury for altitudes from sea level to
the maximum operating altitude of the aircraft; or
(3) Unless the altimeters and digitizers in that equipment meet the
standards of TSO-C10b and TSO-C88, respectively.
(b) After January 1, 2020, no person may operate any automatic
pressure altitude reporting equipment associated with a radar beacon
transponder or with ADS-B Out equipment unless the pressure altitude
reported for ADS-B Out and Mode C/S is derived from the same source for
aircraft equipped with both a transponder and ADS-B Out.
4. Add Sec. 91.225 to read as follows:
Sec. 91.225 Automatic Dependent Surveillance-Broadcast (ADS-B) Out
equipment and use.
(a) After January 1, 2020, and unless otherwise authorized by ATC,
no person may operate an aircraft below Flight Level 240 (FL240) and in
airspace described in paragraph (b) of this section unless the aircraft
is equipped with ADS-B Out equipment that:
(1) Meets the performance requirements in TSO-C166a (1090ES), or
later version; or
(2) Meets TSO-C154b (UAT), or later version; and
(3) Meets the requirements in part 91, Appendix H;
(b) Airspace:
(1) Class A airspace below FL240;
(2) Class B and Class C airspace areas;
(3) All aircraft in all airspace within 30 nautical miles of an
airport listed in appendix D, section 1 of this part from the surface
upward to 10,000 feet MSL;
(4) All aircraft in all airspace above the ceiling and within the
lateral boundaries of a Class B or Class C airspace area designated for
an airport upward to 10,000 feet MSL.
(c) After January 1, 2020, and unless otherwise authorized by ATC,
no person may operate an aircraft at or above FL240 unless the aircraft
is equipped with ADS-B Out equipment that:
(1) Meets the performance requirements in TSO-C166a or later
version; and
(2) Meets the requirements of part 91, Appendix H.
(d) The requirements of paragraphs (a) and (c) of this section, as
appropriate, apply to:
(1) All aircraft in Class E airspace over the Gulf of Mexico from
the coastline of the United States out to 12 nautical miles at and
above 3,000 feet MSL;
(2) All aircraft, except for any aircraft that was not originally
certificated with an electrical system, or which has not subsequently
been certified with such a system installed, including balloons and
gliders, in Class E airspace within the 48 contiguous states and the
District of Columbia at and above 10,000 feet MSL.
(e) The requirements of paragraphs (a), (c), and (d) of this
section do not apply to any aircraft that was not originally
certificated with an electrical system, or which has not subsequently
been certified with such a system installed, including balloons and
gliders, which may conduct operations without ADS-B Out in airspace
within 30 nautical miles of an airport listed in appendix D, section 1
of this part provided such operations are conducted:
(1) Outside any Class B or Class C airspace area; and
(2) Below the altitude of the ceiling of a Class B or Class C
airspace area designated for an airport, or 10,000 feet MSL, whichever
is lower.
(f) Each person operating an aircraft equipped with ADS-B Out must
operate this equipment in the transmit mode at all times except as
otherwise directed by ATC.
(g) Requests for ATC authorized deviations must be made to the ATC
facility having jurisdiction over the concerned airspace within the
time periods specified as follows:
(1) For operation of an aircraft with an inoperative ADS-B Out, to
the airport of ultimate destination, including any intermediate stops,
or to proceed to a place where suitable repairs can be made or both,
the request may be made at any time.
(2) For operation of an aircraft that is not equipped with ADS-B
Out, the request must be made at least one hour before the proposed
operation.
5. Amend appendix D to part 91 by revising section 1 introductory
text to read as follows:
Appendix D to Part 91--Airports/Locations: Special Operating
Restrictions
Section 1. Locations at which the requirements of Sec.
91.215(b)(2) and Sec. 91.225(b)(3) apply. The requirements of Sec.
91.215(b)(2) and Sec. 91.225(b)(3) apply below 10,000 feet above
the surface within a 30-nautical-mile radius of each location in the
following list:
* * * * *
6. Add appendix H to part 91 to read as follows;
Appendix H--Performance Requirements for Automatic Dependent
Surveillance--Broadcast (Ads-B) Out
Section 1. Terms of Reference
ADS-B Out is a function of an aircraft's onboard avionics that
periodically broadcasts the aircraft's state vector (3-dimensional
position and 3-dimensional velocity) and other required information
as described in this appendix.
ADS-B Out operating requirements are defined in 14 CFR 91.225.
Navigation Accuracy Category for Position (NACp) specifies the
accuracy of reported aircraft's position as defined in TSO-C166a and
TSO-C154b.
Navigation Accuracy Category for Velocity (NACv) specifies the
accuracy of reported aircraft's velocity as defined in TSO-C166a and
TSO-C154b.
Navigation Integrity Category (NIC) specifies an integrity
containment region around the aircraft's reported position, as
defined in TSO-C166a and TSO-C154b.
Navigation Position Sensor is the equipment installed onboard an
aircraft used to process and transmit aircraft position (e.g.
location, latitude and longitude, state vector) information.
Surveillance Integrity Level (SIL) indicates the potential risk
that the reported aircraft's position is outside the integrity
containment region described by the NIC parameter, as defined in
TSO-C166a and TSO-C154b.
Section 2. 1090ES and UAT Broadcast Links and Power Requirements
(a) Aircraft operating above FL240 with equipment installed that
meets the minimum performance requirements of TSO-C166a or later
version, must meet the performance requirements of Class A1, A2, A3,
or B1 equipment as defined in TSO-C166a or later version.
(b) Aircraft operating in airspace designated for ADS-B Out and
below FL240 must have equipment installed that meets the performance
requirements of either:
(1) Class A1, A2, A3 or B1 equipment as defined in TSO-C166a or
later version; or
(2) Class A1H, A2, A3, or B1 equipment as defined in TSO-C154b
or later version.
Section 3. ADS-B Out Performance Requirements for NIC, NAC, and SIL
(a) For aircraft broadcasting ADS-B Out as required under Sec.
91.225(a), (c), and (d):
(1) The aircraft's NACp for the positioning source must be
greater than or equal to 9;
(2) The aircraft's NACv for the positioning source must be
greater than or equal to 1;
(3) The aircraft's NIC must be greater than or equal to 7; and
(4) The aircraft's SIL must be 2 or 3.
(b) Changes in the NIC, NAC, or SIL must be broadcast within 10
seconds.
Section 4. Minimum Broadcast Message Element Set for ADS-B Out
Each aircraft must broadcast the following information, as
defined in TSO-C166a or later version, or TSO-C154b or later
version. The pilot must enter information for message elements (g)-
(k) of this section during the appropriate phase of flight:
(a) The length and width of the aircraft;
(b) An indication of the aircraft's lateral and longitudinal
position;
(c) An indication of the aircraft's barometric pressure
altitude;
(d) An indication of the aircraft's velocity;
[[Page 56972]]
(e) An indication if TCAS II or ACAS is installed and operating
in a mode that can generate resolution advisory alerts;
(f) If an operable TCAS II or ACAS is installed, an indication
if a resolution advisory is in effect;
(g) An indication if the flight crew has selected to receive ATC
services;
(h) An indication of the Mode 3/A transponder code specified by
ATC;
(i) An indication of the aircraft's call sign that is submitted
on the flight plan, or the aircraft's registration number;
(j) An indication if the flight crew has identified an emergency
and if so, the emergency status being transmitted;
(k) An indication of the aircraft's ``IDENT'' to ATC;
(l) An indication of the aircraft assigned ICAO 24-bit address;
(m) An indication of the aircraft's emitter category;
(n) An indication whether a cockpit display of traffic
information (CDTI) is installed and operable; and
(o) An indication of the aircraft's geometric altitude.
Section 5. ADS-B Latency Requirements
(a) Upon receipt of the information by the aircraft antenna(s),
the navigation position sensor must process the information in less
than 0.5 seconds.
(b) The processed information from the navigation position
sensor must be transmitted in the ADS-B Out message in less than 1.0
second.
(c) The aircraft must transmit its position and velocity at
least once per second while airborne or while moving on the airport
surface.
(d) The aircraft must transmit its position at least once every
5 seconds while stationary on the airport surface.
Issued in Washington, DC, on October 1, 2007.
Michael A. Cirillo,
Vice President, System Operations Services.
Rick Day,
Vice President, En Route and Oceanic Services.
[FR Doc. 07-4938 Filed 10-2-07; 9:08 am]
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