[Federal Register Volume 62, Number 69 (Thursday, April 10, 1997)]
[Rules and Regulations]
[Pages 17531-17532]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-9244]
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Rules and Regulations
Federal Register
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Federal Register / Vol. 62, No. 69 / Thursday, April 10, 1997 / Rules
and Regulations
[[Page 17531]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM-140; Special Conditions No. 25-ANM-125]
Special Conditions: Lockheed Martin Aerospace Corp. Model L382J
Airplane, High-Intensity Radiated Fields
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for the Lockheed Martin
Aerospace Corp. Model L382J airplane. This model airplane will utilize
new avionics/electronic systems, Mil Std 1553 data buses and dual head-
up displays that provide critical data to the flightcrew. The
applicable regulations do not contain adequate or appropriate safety
standards for the protection of these systems from the effects of high-
intensity radiated fields. 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 April 2, 1997.
Comments must be received on or before May 27, 1997.
ADDRESSES: Comments on these special conditions may be mailed in
duplicate to: Federal Aviation Administration, Office of the Assistant
Chief Counsel, Attn: Rules Docket (ANM-7), Docket No. NM-140, 1601 Lind
Avenue SW., Renton, Washington 98055-4056; or delivered in duplicate to
the Office of the Assistant Chief Counsel at the above address.
Comments must be marked: Docket No. NM-140. Comments may be inspected
in the Rules Docket weekdays, except Federal holidays, between 7:30
a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT: Mike Zielinski, Standardization
Branch, ANM-113, Transport Airplane Directorate, Aircraft Certification
Service, 1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone
(206) 227-2279.
SUPPLEMENTARY INFORMATION:
Comment Invited
The FAA has determined that good cause exists for making these
special conditions effective upon issuance; however, interested persons
are invited to submit such written data, views, or arguments as they
may desire. Communications should identify the regulatory docket and
special condition number and be submitted in duplicate to the address
specified above. All communications received on or before the closing
date for comments will be considered by the Administrator. These
special conditions may be changed in light of the comments received.
All comments submitted will be available in the Rules Docket for
examination by interested persons, both before and after the closing
date for comments. A report summarizing each substantive public contact
with FAA personnel concerning this rulemaking will be filed in the
docket. Persons wishing the FAA to acknowledge receipt of their
comments submitted in response to this request must submit with those
comments a self-addressed, stamped postcard on which the following
statement is made: ``Comments to Docket No. NM-140.'' The postcard will
be date stamped and returned to the commenter.
Background
On August 2, 1992, Lockheed Martin Aerospace Corp. applied for an
amendment to their Type Certificate No. A1SO to include their new Model
L382J. The Model L382J is a derivative of the L382B/E/G currently
approved under Type Certificate No. A1SO, and features a new engine
(with approximately the same rated horsepower, but heavily flat-rated)
and propeller, both of which are controlled by a full authority digital
engine control. Additionally, the flight deck is substantially modified
by the installation of four liquid crystal flight displays, dual head-
up displays, and Mil Std 1553 data buses. The flight engineer position
is deleted, requiring automation of some functions as well as redesign
of the front and overhead panels. Some structure has been modified but
the aerodynamics of the airplane are essentially unchanged. The latest
Part 25 requirement will be used for all significantly modified
portions of the Model 382J (as compared to the present L382), and, for
the unmodified portions of the airplane, the applicable certification
standard will be the Part 25 rules that were effective on February 1,
1965.
Type Certification Basis
Under the provisions of Sec. 21.101, Lockheed Martin Aerospace
Corp. must show that the Model L382J airplanes meet the applicable
provisions of the regulations incorporated by reference in Type
Certificate No. A1SO or the applicable regulations in effect on the
date of application for the changes to the Model L382. In addition, the
certification basis includes certain special conditions and later
amended sections of Part 25 that are not relevant to these proposed
special conditions.
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 L382J because of a novel or
unusual design feature, special conditions are prescribed under the
provisions of Sec. 21.16 to establish a level of safety equivalent to
that established in the regulations.
Special conditions, as appropriate, are issued in accordance with
Sec. 11.49 of the FAR after public notice, as required by Secs. 11.28
and 11.29, and become part of the type certification basis in
accordance with Sec. 21.101(b)(2).
Special conditions are initially applicable to the model for which
they are issued. Should the type certificate for that model be amended
later to include any other model that incorporates the same novel or
unusual design feature, or should any other model already included on
the same type certificate be modified to incorporate the same novel or
unusual design feature, the special conditions would also apply to the
other model under the provisions of Sec. 21.101(a)(1).
Novel or Unusual Design Features
The Model L382J incorporates new avionic/electronic installations,
including a digital Electronic Flight
[[Page 17532]]
Instrument System (EFIS), Mil Std 1553 data buses and dual head-up
displays that provide critical data to the flightcrew and a Full
Authority Digital Engine Control (FADEC) system that controls critical
engine parameters. These systems 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 issued for the L382J which require that new technology
electrical and electronic systems, such as the EFIS, FADEC, HUD, etc.,
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
With the trend toward increased power levels from ground based
transmitters, plus the advent of space and satellite communications,
coupled with electronic command and control of the airplane, the
immunity of critical digital avionics 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 paragraphs 1 or 2 below:
1. A minimum threat of 100 volts per meter peak 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 following field
strengths for the frequency ranges indicated.
------------------------------------------------------------------------
Peak (V/ Average
Frequency M) (V/M)
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10 KHz-100 KHz...................................... 50 50
100 KHz-500 KHz..................................... 60 60
500 KHz-2000 KHz.................................... 70 70
2 MHz-30 MHz........................................ 200 200
30 MHz-100 MHz...................................... 30 30
100 MHz-200 MHz..................................... 150 33
200 MHz-400 MHz..................................... 70 70
400 MHz-700 MHz..................................... 4,020 935
700 MHz-1000 MHz.................................... 1,700 170
1 GHz-2 GHz......................................... 5,000 990
2 GHz-4 GHz......................................... 6,680 840
4 GHz-6 GHz......................................... 6,850 310
6 GHz-8 GHz......................................... 3,600 670
8 GHz-12 GHz........................................ 3,500 1,270
12 GHz-18 GHz....................................... 3,500 360
18 GHz-40 GHz....................................... 2,100 750
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As discussed above, these special conditions would be applicable
initially to the Model L382J. Should Lockheed Martin Aerospace Corp.
apply at a later date for a change to the type certificate to include
another model incorporating the same novel or unusual design feature,
these special conditions would apply to that model as well, under the
provisions of Sec. 21.101(a)(1).
Conclusion
This action affects only certain design features on the Lockheed
Martin Aerospace Corporation Model L382J airplanes. 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 for this airplane has
been submitted to the notice and comment procedure in several prior
instances and has been derived without substantive change from those
previously issued. It is unlikely that prior public comment would
result in a significant change from the substance contained herein. For
this reason, and 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 immediately. Therefore, these special conditions are being
made effective 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.
The authority citation for these proposed special conditions is as
follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
The Special Conditions
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 the Lockheed Martin Aerospace Corp.
Model L382J airplanes.
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 this 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 April 2, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service, ANM-100.
[FR Doc. 97-9244 Filed 4-9-97; 8:45 am]
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