[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]



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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.

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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