[Federal Register Volume 70, Number 238 (Tuesday, December 13, 2005)]
[Rules and Regulations]
[Pages 73559-73561]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-23935]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM336; Special Conditions No. 25-309-SC]
Special Conditions: Sabreliner Model NA-265-60 Airplanes; High-
Intensity Radiated Fields (HIRF).
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for Sabreliner Model NA-
265-60 airplanes modified by Flight Research, Inc. These modified
airplanes will have a novel or unusual design feature when compared to
the state of technology envisioned in the airworthiness standards for
transport category airplanes. The modification incorporates the
installation of altimeter/air data display units manufactured by
Innovative Solutions and Support, Inc. These display units perform
critical functions. 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 established by the existing
airworthiness standards.
DATES: The effective date of these special conditions is December 5,
2005. We must receive your comments by January 12, 2006.
ADDRESSES: You must mail two copies of your comments to: Federal
Aviation Administration, Transport Airplane Directorate, Attention:
Rules Docket (ANM-113), Docket No. NM336, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. You may deliver two copies to the
Transport Airplane Directorate at the above address. You must mark your
comments: Docket No. NM336. You can inspect comments in the Rules
Docket weekdays, except Federal Holidays, between 7:30 a.m. and 4 p.m.
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-
1320.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA has determined that notice and opportunity for prior public
comment is 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, we invite interested people to take part in this
rulemaking by sending 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. You may inspect the docket 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 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 May 6, 2005, Flight Research, Inc., 1062 Flight Line, Hangar
161, Mojave, California 93501, applied for a Supplemental Type
Certificate (STC) to modify Sabreliner Model NA-265-60 airplanes. These
models are currently approved under Type Certificate No. A2WE. The
Sabreliner Model NA-265-60 is a transport category airplane powered by
two Pratt and Whitney Turbo Wasp JT12A-8 engines. The maximum takeoff
weight is 20,172 pounds. These airplanes operate with a 2-person crew
and can seat up to 10 passengers. The modification incorporates the
installation of altimeter/air data display units manufactured by
Innovative Solutions and Support, Inc. The avionics/electronics and
electrical systems installed in this airplane have the potential to be
vulnerable to high-intensity radiated fields (HIRF) external to the
airplane.
Type Certification Basis
Under the provisions of 14 CFR 21.101, Flight Research, Inc. must
show that the Sabreliner Model NA-265-60, as changed, continues to meet
the applicable provisions of the regulations incorporated by reference
in Type Certificate No. A2WE, 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
Sabreliner Model NA-265-60 airplanes includes Civil Aeronautics Manual
4b, as amended by Amendment 4b-1 through Amendment 4b-9, Special Civil
Air Regulation No. SR 422B Item 2, the Special Conditions set forth in
Attachment ``A'' of FAA letter to NAA [North American Aviation] dated
October 8, 1959, and FAA letter to NAA dated January 30, 1962.
If the Administrator finds that the applicable airworthiness
regulations
[[Page 73560]]
(i.e., part 25, as amended) do not contain adequate or appropriate
safety standards for the Sabreliner Model NA-265-60 airplanes because
of a novel or unusual design feature, special conditions are prescribed
under Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the Sabreliner Model NA-265-60 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 14 CFR 11.19, are issued under
Sec. 11.38 and become part of the type certification basis under Sec.
21.101.
Special conditions are initially applicable to the model for which
they are issued. Should Flight Research, Inc. apply at a later date for
a supplemental type certificate to modify any other model included on
Type Certificate No. A2WE to incorporate the same or similar novel or
unusual design feature, these special conditions would also apply to
the other model under Sec. 21.101.
Novel or Unusual Design Features
As noted earlier, the Sabreliner Model NA-265-60 airplanes modified
by Flight Research, Inc. will incorporate altimeter/air data display
units that will perform critical functions. These display units may be
vulnerable to high-intensity radiated fields external to the airplane.
The current airworthiness standards of part 25 do not contain adequate
or appropriate safety standards for the protection of this equipment
from the adverse effects of HIRF. Accordingly, these systems are
considered to be a novel or unusual design feature.
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 avionics/electronics and electrical 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 Sabreliner Model NA-265-60 airplanes
modified by Flight Research, Inc. These special conditions require that
new avionics/electronics and electrical systems 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 avionics/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
identified in the table below for the frequency ranges indicated. Both
peak and average field strength components from the table are to be
demonstrated.
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Field Strength (volts
per meter)
Frequency -------------------------
Peak Average
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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
100MHz-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
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The field strengths are expressed in terms of peak of the root-mean-
square (rms) over the complete modulation period.
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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 to
Sabreliner Model NA-265-60 airplanes modified by Flight Research, Inc.
Should Flight Research, Inc. apply at a later date for a supplemental
type certificate to modify any other model included on Type Certificate
No. A2WE to incorporate the same or similar novel or unusual design
feature, these special conditions would apply to that model as well
under provisions of Sec. 21.101.
[[Page 73561]]
Conclusion
This action affects only certain novel or unusual design features
on Sabreliner Model NA-265-60 airplanes modified by Flight Research,
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 the
airplane.
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.
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 supplemental type certification basis for the Sabreliner Model NA-
265-60 airplanes modified by Flight Research, 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 December 5, 2005.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-23935 Filed 12-12-05; 8:45 am]
BILLING CODE 4910-13-P