[Federal Register Volume 60, Number 26 (Wednesday, February 8, 1995)]
[Proposed Rules]
[Pages 7479-7480]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-3123]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. ANM-106; Notice No. SC-95-2-NM]
Special Conditions: Raytheon Corporate Jets, Inc., Model Hawker
800 Airplanes, High-Intensity Radiated Fields
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed special conditions.
-----------------------------------------------------------------------
SUMMARY: This notice proposes special conditions for the Raytheon
Corporate Jets, Inc., Model Hawker 800 airplanes equipped with
modifications that install Garrett TFE731-5BR-1H engines and a mach
trim system. The configuration of these airplanes will utilize new and
revised electronic systems that perform functions critical to the
safety of the airplane. 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
proposed 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: Comments must be received on or before March 27, 1995.
ADDRESSES: Comments on this proposal may be mailed in duplicate to:
Federal Aviation Administration, Transport Airplane Directorate (ANM-
100), Attn: Docket No. NM-106, 1601 Lind Avenue SW., Renton,
Washington, 98055-4056; or delivered in duplicate to the Transport
Airplane Directorate at the above address. Comments must be marked:
Docket No. NM-106. Comments may be inspected in the Rules Docket
weekdays, except Federal holidays, between 7:30 a.m. and 4:00 p.m.
FOR FURTHER INFORMATION CONTACT:
William Schroeder, FAA, Standardization Branch, ANM-113, Transport
Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue
SW., Renton, Washington, 98055-4056.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of
these proposed special conditions by submitting such written data,
views, or arguments as they may desire. Communications should identify
the regulatory docket or notice 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
before further rulemaking action is taken on these proposals. The
proposals contained in this notice may be changed in light of 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 notice must submit with those
comments a self-addressed, stamped postcard on which the following
statement is made: ``Comments to Docket No. NM-106.'' The postcard will
be date stamped and returned to the commenter.
Background
On February 7, 1994, Raytheon Corporate Jets, Inc., 3 Bishop
Square, St. Albans Road West, Hatfield, Hertfordshire AL10 9NE,
England, applied for a revision to type certificate number A3EU to add
new engines and a mach trim system to the model Hawker 800 series
airplanes currently included on that TC. This revised model Hawker 800
is a crusifix tail, low wing, 15 passenger business jet powered by two
Garrett TFE 731-5BR-1H turbofan engines mounted on pylons extending
from the aft fuselage. The engines will be capable of delivering 4,634
lbs. of max continuous thrust each and 4750 pounds of thrust on the
operating engine for up to 5 minutes at automatic power reserve (APR)
power.
Type Certification Basis
Under the provisions of Sec. 21.29 of the FAR, Raytheon must show,
except as provided in Sec. 25.2, that the revised Model Hawker 800
complies with the certification basis of record shown on TC Data Sheet
A3EU for model Hawker 800 airplanes plus, for the engine and mach trim
system installations, Sec. 25.1316 as amended by Amendment 25-80,
Sec. 25.933 as amended by Amendment 25-40, Sec. 25.934 as amended
through Amendment 25-23, Sec. 25.1309 as amended through Amendment 25-
23, parts 34 and 36 of the FAR as amended through the latest amendment
in effect at the time of certification of this revision to the TC and
any additional equivalent safety findings made for this revision of the
TC. The special conditions that may be developed as a result of this
notice will form an additional part of the 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 model Hawker 800 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. 21.29(a)(1)(ii) and Sec. 21.17(a)(2).
Special conditions are initially applicable to the model for which
they [[Page 7480]] 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 Hawker 800 airplanes with TFE731-5BR-1H engines
incorporate a revised engine electronic control system and an
electronic controlled mach trim system. These systems perform critical
to safety of flight functions and may be vulnerable to high-intensity
radiated fields 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 proposed for the model Hawker 800 with TFE731-5BR-1H
engines and a mach trim system. These special conditions require that
electrical and electronic components that perform critical functions
and are embodied in the mach trim system or TFE731-5BR-1H engine
electronic control system be designed and installed to ensure that
operation and operational capabilities of these systems to perform
critical functions are not adversely affected when the airplane is
exposed to HIRF.
High-Intensity Radiated Fields (HIRF)
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 electronic 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(V/
Frequency M) M)
------------------------------------------------------------------------
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
------------------------------------------------------------------------
As discussed above, the proposed special conditions would be
applicable initially to certain components on Hawker 800 airplanes with
TFE731-5BR engines and a mach trim system. Should Raytheon Corporate
Jets, Inc. apply at a later date for a change to the type certificate
to add or revise electrical or electronic equipment that performs
critical functions or 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 Hawker 800
airplane. It is not a rule of general applicability and affects only
the manufacturer who applied to the FAA for approval of these features
on the airplane.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Federal Aviation Administration,
Reporting and recordkeeping requirements.
The authority citation for these proposed 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 Proposed Special Conditions
Accordingly, the Federal Aviation Administration (FAA) proposes the
following special conditions as part of the type certification basis
for Raytheon Hawker 800 series airplanes equipped with Garrett TFE731-
5BR-1H turbo fan engines and electronically controlled mach trim
system. These special conditions would apply only to electrical and
electronic components that perform critical functions and are embodied
in the mach trim system or TFE731-5BR-1H engine electronic control
system.
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, Wash., on January 31, 1995.
Darrell M. Pederson,
Assistant Manager, Transport Airplane Directorate, Aircraft
Certification Service, ANM-101.
[FR Doc. 95-3123 Filed 2-7-95; 8:45 am]
BILLING CODE 4910-13-M