[Federal Register Volume 61, Number 241 (Friday, December 13, 1996)]
[Rules and Regulations]
[Pages 65460-65462]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31728]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM-136; Special Conditions No. 25-ANM-122]


Special Conditions: Gulfstream Model G1159A 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 Gulfstream Model 
G1159A airplane, modified by Chrysler Pentastar to include a Flight 
Vision Heads-Up Display (FV-2000) system, that provides critical data 
to the flightcrew. The applicable regulations do not contain adequate 
or appropriate safety standards for the protection of this system from 
the effects of high-intensity radiated fields (HIRF). 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 December 4, 
1996. Comments must be received on or before January 13, 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-136, 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-136. 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:
Connie Bean, FAA, Standardization Branch, ANM-113, Transport Airplane 
Directorate, Aircraft Certification Service, 1601 Lind Avenue SW., 
Renton, Washington, 98055-4056; telephone (206) 227-2796; facsimile 
(206) 227-1149.

[[Page 65461]]

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 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-136.'' The postcard will 
be date stamped and returned to the commenter.

Background

    Chrysler Pentastar Aviation, Inc., Waterford, Michigan, has applied 
for a supplemental type certificate in the transport airplane category 
for the Gulfstream Model G1159A, modified to include a new Flight 
Vision Heads-UP Display (FV-2000) system. The Model G1159A is a T-tail, 
low swept-wing, small transport airplane powered by two Rolls Royce 
SPEY RB (163-25) engines mounted on pylons extending from the aft 
fuselage. The airplane has a maximum takeoff weight of 69,700 pounds.

Type Certification Basis

    Under the provisions of Sec. 21.101 of 14 CFR part 21, Chrysler 
Pentastar must show that the Model G1159A, as changed, continues to 
meet the applicable provisions of the regulations incorporated by 
reference in Type Certificate A12EA, 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. A12EA are as follows:

    Part 25 of the FAR, effective February 1, 1965, as amended by 
Amendments 25-1 through 25-8, 25-10, 25-12, 25-16 through 25-22, 25-
24, 25-26, 25-27, 25-29 through 25-31, 25-34, 25-37, 25-40 (as 
applicable to a new APU installation); Sec. 25.1309, as amended by 
Amendment 25-41, and Sec. 25.329 (as applied to a new autopilot 
installation), Sec. 25.994 (crashworthiness fuel system components), 
and Sec. 25.581 (lightning protection), as amended by Amendment 25-
23; Special FAR part 27, as amended by Amendment 27-2 (fuel venting 
emission); and part 36, as amended by Amendment 36-8 (noise 
requirements). The special conditions contained in the FAA's letter 
to Grumman dated September 27, 1965, applicable to the Gulfstream 
Model G-1159 airplane, are also applicable to the Gulfstream Model 
G-11159A airplane, except that reference to Sec. 4b.450 in the 
``Cooling Systems'' special conditions is replaced by Sec. 25.1043, 
effective February 1, 1965. In addition, the certification basis 
includes special conditions pertaining to dynamic gust loads 
contained in the enclosed to FAA AEA-212 letter dated July 22, 1980.

    These special conditions 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 Gulfstream Model G1159A because of 
a novel or unusual design feature, special conditions are prescribed 
under the provisions of Sec. 21.16.
    Special conditions, as appropriate, are issued in accordance with 
14 CFR Sec. 11.49 after public notice, as required by Secs. 11.28 and 
11.29(b), 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 supplemental type 
certificate to modify any other model included on the same type 
certificate to incorporate the same novel or unusual design feature, 
these 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 G1159A is modified to incorporate a new avionic/
electronic installation, including the Flight Vision Heads-Up Display 
(FV-2000) system. This system 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, a special 
condition is needed for the Model G-1159A, as modified by Chrysler 
Pentastar, which requires that new electrical and electronic systems, 
such as the Heads-Up Display, that perform critical functions 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 (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 avionics systems, such as Heads-Up 
Display, 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) 
------------------------------------------------------------------------
10 KHz-100 KHz......................................        50        50
100 KHz-500 KHz.....................................        60        60
500 KHz-2 MHz.......................................        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-1 GHz.......................................     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

[[Page 65462]]

                                                                        
12 GHz-18 GHz.......................................     3,500       360
18 GHz-40 GHz.......................................     2,100       750
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    As discussed above, these special conditions are applicable to the 
Gulfsteam Model G-1159A, modified by Chrysler Pentastar to incorporate 
a Flight Vision Heads-Up Display. Should Chrysler Pentastar apply at a 
later date for a Supplemental Type Certificate to modify any other 
model included on Type Certificate No. A12EA to incorporate 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 Gulfstream 
Model G-1159A airplanes, modified by Chrysler Pentastar to include a 
Flight Vision Heads-Up Display. 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 this airplane has been 
subject 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 record keeping 
requirements.

    The authority citation for this special condition 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 supplemental type certification basis for the Gulfstream Model G-
1159A airplane, as modified by Chrysler Pentastar.
    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 condition, the following 
definition applied: 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 December 4, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate Aircraft Certification 
Service, ANM-100.
[FR Doc. 96-31728 Filed 12-12-96; 8:45 am]
BILLING CODE 4910-13-M