[Federal Register Volume 59, Number 106 (Friday, June 3, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-13521]
[[Page Unknown]]
[Federal Register: June 3, 1994]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM-96; Special Conditions No. 25-ANM-85]
Special Conditions: Modified AMD/BA Falcon 50 Series Airplanes,
High Intensity Radiated Fields (HIRF)
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for AMD/BA Falcon 50
series airplanes modified by Duncan Aviation, Inc., of Lincoln,
Nebraska. These airplanes are equipped with digital electronic flight
instrument systems (EFIS) that perform critical functions. The
applicable regulations do not contain adequate or appropriate safety
standards for the protection of the EFIS from the effects of high-
intensity radiated fields (HIRF). These special conditions provide the
additional safety standards that the Administrator considers necessary
to ensure that the critical functions performed by these systems are
maintained when the airplane is exposed to HIRF.
DATES: The effective date of these special conditions is May 24, 1994.
Comments must be received on or before July 18, 1994.
ADDRESSES: Comments on these final special conditions; request for
comments, may be mailed in duplicate to: Federal Aviation
Administration, Office of the Assistant Chief Counsel, Attn.: Rules
Docket (ANM-7), Docket No. NM-96, 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-96.'' 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:
Mark Quam, FAA, Standardization Branch, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind Avenue SW., Renton,
Washington 98055-4056; telephone (206) 227-2145.
SUPPLEMENTARY INFORMATION:
Comments 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 conditions 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-96.'' The postcard will
be date stamped and returned to the commenter.
Background
On April 15, 1994, Duncan Aviation, Inc., of Lincoln, Nebraska,
applied for a supplemental type certificate to modify the AMD/BA Falcon
50 series airplanes. The AMD/BA Falcon 50 is a business jet with three
aft-mounted turbojet engines. The airplane can carry two pilots and 8
to 19 passengers, depending on the exit and interior configuration, and
is capable of operating to an altitude of 45,000 feet. The proposed
modification incorporates the installation of digital avionics
consisting of an electronic flight instrument system (EFIS) that is
potentially vulnerable to high-intensity radiated fields (HIRF)
external to the airplane.
Supplemental Type Certification Basis
Under the provisions of Sec. 21.101 of the Federal Aviation
Regulations (FAR), Duncan Aviation, Inc., must show that the altered
AMD/BA Falcon 50 series airplanes continue to meet the applicable
provisions of the regulations incorporated by reference in Type
Certificate No. A46EU, 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 regulations incorporated by reference in Type Certificate No.
A46EU include the following for the AMD/BA Falcon 50 series: Sec. 21.29
of part 21, and 14 CFR part 25, dated February 1, 1965, as amended by
Amendments 25-1 through 25-34. In addition the following regulations
apply to the EFIS installation: Secs. 25.1303(b) and 25.1322, as
amended through Amendment 25-38; and Secs. 25.1309, 25.1321(a), (b),
(d), and (e), 25.1331, 25.1333, and 25.1335, as amended by Amendment
25-41. These special conditions will form an additional part of the
supplemental type certification basis.
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 AMD/BA Falcon 50 series airplanes
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 applicant apply for a supplemental type
certificate to modify any other model included on the same type
certificate 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).
Discussion
There is no specific regulation that addresses protection
requirements for electrical and electronic systems from high-intensity
radiated fields (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 modified AMD/BA Falcon 50 series
airplanes that would require that the EFIS be designed and installed to
preclude component damage and interruption of function due to the
effects of HIRF.
High-Intensity Radiated Fields (HIRF)
When 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, such as the EFIS, 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 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-70 MHz....................................... 30 30
70 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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The envelope given in paragraph 2 above is a revision to the
envelope used in previously issued special conditions in other
certification projects. It is based on new data and SAE AE4R
subcommittee recommendations. This revised envelope includes data from
Western Europe and the U.S.
As discussed above, these special conditions are applicable to the
AMD/BA Falcon 50 series airplanes, modified by Duncan Aviation. Should
Duncan Aviation apply at a later date for a supplemental type
certificate to modify any other model included on Type Certificate No.
A46EU to incorporate the same novel or unusual design feature, the
special conditions would apply to that model as well, under the
provisions of Sec. 21.101(a)(1).
Conclusion
This action affects only certain unusual or novel design features
on the AMD/BA Falcon 50 series 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 the special conditions for these airplanes has
been subjected 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 special conditions is as follows:
Authority: 49 U.S.C. app. 1344, 1348(c), 1352, 1354(a), 1355,
1421 through 1431, 1502, 1651(b)(2), 42 U.S.C. 1857f-10, 4321 et
seq.; E.O. 11514; and 49 U.S.C. 106(g).
The Special Conditions
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 modified AMD/BA
Falcon 50 series 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 external to the airplane.
2. The following definition applies with respect to this special
condition: Critical Function. 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
May 24, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service, ANM-100.
[FR Doc. 94-13521 Filed 6-2-94; 8:45 am]
BILLING CODE 4910-13-M
