[Federal Register: September 19, 2003 (Volume 68, Number 182)]
[Rules and Regulations]
[Page 54800-54802]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19se03-2]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM265, Special Conditions No. 25-247-SC ]
Special Conditions: Douglas Models DC-8-61, -61F, -63, -63F, -71,
-71F, -72, -72F, -73, and -73F Airplanes; High Intensity Radiated
Fields (HIRF)
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued for Douglas Models DC-8-
61, -61F, -63, -63F, -71, -71F, -72, -72F, -73, and -73F airplanes
modified by ABX Air, Inc. These airplanes, as modified by ABX Air,
Inc., will have novel and unusual design features when compared to the
state of technology envisioned in the airworthiness standards for
transport category airplanes. The modification incorporates the
installation of the Innovative Solutions and Support (IS&S) Duplex
Reduced Vertical Separation Minimum (RVSM) system which will allow for
the removal of the existing altitude alerter, encoding altimeters, air
data computer, and standby altimeter. The applicable airworthiness
regulations do not contain adequate or appropriate safety standards for
the protection of these systems from the effects of high intensity
radiated fields (HIRF). These special conditions contain the additional
safety standards that the Administrator considers necessary to
establish a level of safety equivalent to that provided by the existing
airworthiness standards.
DATES: The effective date of these special conditions is September 10,
2003. Comments must be received on or before October 20, 2003.
ADDRESSES: Comments on these special conditions may be mailed in
duplicate to: Federal Aviation Administration, Transport Airplane
Directorate, Attn: Rules Docket (ANM-113), Docket No. NM265, 1601 Lind
Avenue SW., Renton, Washington, 98055-4056; or delivered in duplicate
to the Transport Airplane Directorate at the above address. All
comments must be marked: Docket No. NM265.
FOR FURTHER INFORMATION CONTACT: Greg Dunn, FAA, Airplane and Flight
Crew Interface Branch, ANM-111, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind Avenue SW., Renton,
Washington, 98055-4056; telephone (425) 227-2799; facsimile (425) 227-
1149.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA has determined that notice and opportunity for prior public
comment are impracticable because these procedures would significantly
delay certification of the airplane and thus delivery of the affected
aircraft. In addition, the substance of these special conditions has
been subject to the public comment process in several prior instances
with no substantive comments received. The FAA therefore finds that
good cause exists for making these special conditions effective upon
issuance; however, the FAA invites interested persons to participate in
this rulemaking by submitting written comments, data, or views. The
most helpful comments reference a specific portion of the special
conditions, explain the reason for any recommended change, 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 these special conditions. The docket is available for public
inspection before and after the comment closing date. If you wish to
review the docket in person, go to the address in the ADDRESSES section
of this preamble between 7:30 a.m. and 4:00 p.m., Monday through
Friday, except Federal holidays.
We will consider all comments we receive on or before the closing
date for comments. We will consider comments filed late if it is
possible to do so without incurring expense or delay. We may change
these special conditions based on the comments we receive.
If you want the FAA to acknowledge receipt of your comments on
these special conditions, 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 back to you.
Background
On November 25, 2002, ABX Air Inc. applied for a supplemental type
certificate (STC) to modify Douglas Models DC-8-61, -61F, -63, -63F, -
71, -71F, -72, -72F, -73, and -73F airplanes. These models are
currently approved under Type Certificate 4A25. The modification
incorporates the installation of the IS&S Duplex RVSM system which will
allow for the removal of the existing altitude alerter, encoding
altimeters, air data computer, and standby altimeter. This system uses
two Air Data Display Units (ADDU) and a single Analog Interface Unit
(AIU) to replace altitude displays and the air data computer. These
displays can be susceptible to disruption to both command and response
signals as a result of electrical and magnetic interference. This
disruption of signals could result in the loss of all critical flight
information displays and annunciations or the presentation of
misleading information to the pilot.
Type Certification Basis
Under the provisions of 14 CFR 21.101, ABX Air Inc. must show that
Douglas Models DC-8-61, -61F, -63, -63F, -71, -71F, -72, -72F, -73, and
-73F airplanes, as changed, continue to meet the applicable provisions
of the regulations incorporated by reference in Type Certificate No.
4A25, or the applicable regulations in effect on the date of
application for the change. The regulations incorporated by reference
in the type certificate are commonly referred to as the ``original type
certification basis.'' The certification basis for the modified Douglas
Models DC-8-61, -61F, -63, -63F, -71, -71F, -72, -72F, -73, and -73F
airplanes include 14 CFR part 25 effective February 1, 1965 as
described in Type Certificate Data Sheet 4A25.
[[Page 54801]]
If the Administrator finds that the applicable airworthiness
regulations (i.e., part 25, as amended) do not contain adequate or
appropriate safety standards for the Douglas Models DC-8-61, -61F, -63,
-63F, -71, -71F, -72, -72F, -73, and -73F airplanes because of a novel
or unusual design feature, special conditions are prescribed under the
provisions of Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the Douglas Models DC-8-61, -61F, -63, -63F, -71, -71F, -
72, -72F, -73, and -73F airplanes must comply with the fuel vent and
exhaust emission requirements of 14 CFR part 34 and the noise
certification requirements of 14 CFR part 36.
Special conditions, as defined in Sec. 11.19, are issued in
accordance with Sec. 11.38 and become part of the type certification
basis in accordance with Sec. 21.101.
Special conditions are initially applicable to the models for which
they are issued. Should ABX Air, Inc., apply at a later date for a
supplemental type certificate to modify any other models included on
Type certificate No. 4A25 to incorporate the same or similar novel or
unusual design feature, the special conditions would also apply to the
other model under the provisions of Sec. 21.101.
Novel or Unusual Design Features
The modified Douglas Models DC-8-61, -61F, -63, -63F, -71, -71F, -
72, -72F, -73, and -73F airplanes will incorporate a new altitude
display system, the Innovative Solutions and Support (IS&S) Duplex
Reduced Vertical Separation Minimum (RVSM) system, which was not
available at the time of certification of these airplanes, that
performs critical functions. This system may be vulnerable to high-
intensity radiated fields (HIRF) external to the airplane.
Discussion
There is no specific regulation that addresses protection
requirements for electrical and electronic systems from HIRF. Increased
power levels from ground-based radio transmitters and the growing use
of sensitive electrical and electronic systems to command and control
airplanes have made it necessary to provide adequate protection.
To ensure that a level of safety is achieved equivalent to that
intended by the regulations incorporated by reference, special
conditions are needed for the Douglas Models DC-8-61, -61F, -63, -63F,
-71, -71F, -72, -72F, -73, and -73F airplanes, modified by ABX Air,
Inc. These special conditions require that new electrical and
electronic systems, such as the ADDU, that perform critical functions,
be designed and installed to preclude component damage and interruption
of function due to both the direct and indirect effects of HIRF.
High-Intensity Radiated Fields (HIRF)
With the trend toward increased power levels from ground-based
transmitters, and the advent of space and satellite communications,
coupled with electronic command and control of the airplane, the
immunity of critical digital avionic/electronics and electrical systems
to HIRF must be established.
It is not possible to precisely define the HIRF to which the
airplane will be exposed in service. There is also uncertainty
concerning the effectiveness of airframe shielding for HIRF.
Furthermore, coupling of electromagnetic energy to cockpit-installed
equipment through the cockpit window apertures is undefined. Based on
surveys and analysis of existing HIRF emitters, an adequate level of
protection exists when compliance with the HIRF protection special
condition is shown with either paragraph 1 or 2 below:
1. A minimum threat of 100 volts rms (root-mean-square) per meter
electric field strength from 10 KHz to 18 GHz.
a. The threat must be applied to the system elements and their
associated wiring harnesses without the benefit of airframe shielding.
b. Demonstration of this level of protection is established through
system tests and analysis.
2. A threat external to the airframe of the field strengths
indicated in the table below for the frequency ranges indicated. Both
peak and average field strength components from the table below are to
be demonstrated.
------------------------------------------------------------------------
Field strength (volts
per meter)
Frequency -------------------------
Peak Average
------------------------------------------------------------------------
10 kHz-100 kHz................................ 50 50
100 kHz-500 kHz............................... 50 50
500 kHz-2 MHz................................. 50 50
2 MHz-30 MHz.................................. 100 100
30 MHz-70 MHz................................. 50 50
70 MHz-100 MHz................................ 50 50
100 MHz-200 MHz............................... 100 100
200 MHz-400 MHz............................... 100 100
400 MHz-700 MHz............................... 700 50
700 MHz-1 GHz................................. 700 100
1 GHz-2 GHz................................... 2000 200
2 GHz-4 GHz................................... 3000 200
4 GHz-6 GHz................................... 3000 200
6 GHz-8 GHz................................... 1000 200
8 GHz-12 GHz.................................. 3000 300
12 GHz-18 GHz................................. 2000 200
18 GHz-40 GHz................................. 600 200
------------------------------------------------------------------------
The field strengths are expressed in terms of peak of the root-mean-
square (rms) over the complete modulation period.
The threat levels identified above are the result of an FAA review
of existing studies on the subject of HIRF, in light of the ongoing
work of the Electromagnetic Effects Harmonization Working Group of the
Aviation Rulemaking Advisory Committee.
Applicability
As discussed above, these special conditions are applicable Douglas
Models DC-8-61, -61F, -63, -63F, -71, -71F, -72, -72F, -73, and -73F
airplanes modified by ABX Air Inc. Should ABX Air Inc. apply at a later
date for a supplemental type certificate to modify any other model
included on Type Certificate No. 4A25 to incorporate the same or
similar novel or unusual design feature, these special conditions would
apply to that model as well under the provisions of Sec. 21.101.
Conclusion
This action affects only certain novel or unusual design features
on Douglas Models DC-8-61, -61F, -63, -63F, -71, -71F, -72, -72F, -73,
and -73F airplanes modified by ABX Air Inc. It is not a rule of general
applicability and affects only the applicant who applied to the FAA for
approval of these features on these airplanes.
The substance of these special conditions has been subjected to the
notice and comment procedure in several prior instances and has been
derived without substantive change from those previously issued.
Because a delay would significantly affect the certification of the
airplane, which is imminent, the FAA has determined that prior public
notice and comment are unnecessary and impracticable, and good cause
exists for adopting these special conditions upon issuance. The FAA is
requesting comments to allow interested persons to submit views that
may not have been submitted in response to the prior opportunities for
comment described above.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
0
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
[[Page 54802]]
The Special Conditions
0
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for Douglas Models DC-8-61, -61F, -63, -
63F, -71, -71F, -72, -72F, -73, and -73F airplanes modified by ABX Air
Inc.
1. Protection from Unwanted Effects of High-Intensity Radiated
Fields (HIRF). Each electrical and electronic system that performs
critical functions must be designed and installed to ensure that the
operation and operational capability of these systems to perform
critical functions are not adversely affected when the airplane is
exposed to high-intensity radiated fields.
2. For the purpose of these special conditions, the following
definition applies:
Critical Functions. Functions whose failure would contribute to or
cause a failure condition that would prevent the continued safe flight
and landing of the airplane.
Issued in Renton, Washington, on September 10, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 03-23970 Filed 9-18-03; 8:45 am]
BILLING CODE 4910-13-P