[Federal Register Volume 60, Number 95 (Wednesday, May 17, 1995)]
[Rules and Regulations]
[Pages 26357-26359]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-12155]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. ANM-106; Special Conditions No. 25-ANM-98]


Special Conditions; Raytheon Corporate Jets, Inc., Model Hawker 
800 Airplanes, High-Intensity Radiated Fields

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final special conditions.

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SUMMARY: These special conditions are 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 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.

EFFECTIVE DATE: June 16, 1995.

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:

Background

    On February 7, 1994, Raytheon Corporate Jets, Inc., 3 Bishop 
Square, St. Albans Road West, Hatfield, Hertfordshire AL 10 9NE, 
England, applied for a revision to type certificate 
[[Page 26358]] number A3EU to add new engines and a mach system to the 
Model Hawker 800 series airplanes currently included on that TC. This 
revised Model Hawker 800 is a cruciform 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 mzx continous 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. These special conditions form an additional part of the type of 
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 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 
strength for the frequency ranges indicated.

------------------------------------------------------------------------
                                                      Peak (V/  Average 
                      Frequency                          M)      (V/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-4GHz..........................................    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, these special conditions are applicable 
initially to certain components on Model Hawker 800 airplane 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).

Discussion of Comments

    Notice of Proposed Special Conditions No. SC-95-2-NM for the 
Raytheon Corporate Jets, Inc., Model Hawker 800 Airplanes, was 
published in the Federal Register on February 8, 1995 (60 FR 7479). No 
comments were received.

Conclusion

    This action affects only certain design features on the Model 
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, [[Page 26359]] 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, the following special conditions are issued as part of 
the type certification basis for the Raytheon Corporate Jets, Inc., 
Model 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, Washington, on May 9, 1995.
Darrell M. Pederson,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service, ANM-101.
[FR Doc. 95-12155 Filed 5-16-95; 8:45 am]
BILLING CODE 4910-13-M