[Federal Register Volume 65, Number 235 (Wednesday, December 6, 2000)]
[Rules and Regulations]
[Pages 76147-76149]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-31085]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM179; Special Conditions No. 25-168-SC]


Special Conditions: Gulfstream Aerospace Corporation Model G-
1159, G-1159A, and G-1159B Series Airplanes as Modified by Duncan 
Aviation; High Intensity Radiated Fields (HIRF)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Gulfstream Model 
G-1159, G-1159A, and G-1159B series airplanes modified by Duncan 
Aviation. These modified airplanes will have a novel or unusual design 
feature(s) associated with new avionics/electronics and electrical 
systems that will perform critical functions. The applicable 
airworthiness regulations do not contain adequate or appropriate safety 
standards for the protection of these systems from the effects of high-
intensity radiated fields (HIRF). These special conditions contain the 
additional safety standards 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 November 29, 
2000. Comments must be received on or before January 22, 2001.

ADDRESSES: Comments on these special conditions may be mailed in 
duplicate to: Federal Aviation Administration, Transport Airplane 
Directorate, Attention: Rules Docket (ANM-114), Docket No. NM179, 1601 
Lind Avenue SW., Renton, Washington 98055-4056; or delivered in 
duplicate to the Transport Airplane Directorate at that address. All 
comments must be marked: Docket No. NM179. 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: For information concerning the 
certification program for Gulfstream Model G-1159, G-1159A, and G-1159B 
series airplanes, contact: Meghan Gordon, Federal Aviation 
Administration, Transport Airplane Directorate, Standardization Branch, 
ANM-113, 1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone 
(425) 227-2138; fax (425) 227-1149.
    For information on the general subject of HIRF, contact: Massoud 
Sadeghi, Federal Aviation Administration, Transport airplane 
Directorate, Airplane and Flight Crew Interface Branch, ANM-111, 1601 
Lind Avenue SW., Renton, Washington 98055-4056; telephone (425) 227-
2117; fax (425) 227-1320.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice and 
opportunity for prior public comment hereon are impracticable because 
these procedures would significantly delay issuance of the approval 
design and thus delivery of the affected aircraft. In addition, the 
substance of these special conditions has been subject to the public 
comment process in several prior instances with no substantive comments 
received. The FAA therefore finds that good cause exists for making 
these special conditions effective upon issuance.

Comments Invited

    Although these special conditions are being issued as final special 
conditions without prior public notice, interested persons are invited 
to submit such written data, views, or arguments as they may desire. 
Communications should identify the regulatory docket 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. The special conditions may be 
changed in light of the comments received. All comments received 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. Commenters 
wishing the FAA to acknowledge receipt of their comments submitted in 
response to these special conditions must include a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to NM179.'' The postcard will be date stamped and returned to the 
commenter.

Background

    On September 13, 2000, and on September 20, 2000, Duncan Aviation, 
15745 South Airport Road, Battle Creek, Michigan 49015, submitted 
applications to the FAA for two Supplemental Type Certificates (STC). 
These STC's are for modifying Gulfstream Aerospace Model G-1159, G-
1159A, and G-1159B series airplanes to include:
    <bullet> The Collins FDS-2000 Flight Display System; and
    <bullet> Dual Collins AHS-3000A Altitude Heading Reference Systems.
    The FDS-2000 system is a replacement of the existing electro-
mechanical Attitude Directional Indicator (ADI) and Horizontal 
Situational Indicator (HSI) flight instruments. It also provides 
additional functional capability and redundancy in the system.
    The AHS-3000A system is a replacement for the existing electro-
mechanical vertical and directional gyros. It also provides additional 
functional capability and redundancy in the system.
    The avionics/electronics and electrical systems installed in the 
Gulfstream Model G-1159, G-1159A, and G-1159B airplanes have the 
potential to be vulnerable to high-intensity radiated fields (HIRF) 
external to the airplane.
    The subject Gulfstream airplanes are T-tail, low swept-wing small 
transport category airplanes. The Model G-1159 airplane is powered by 
two Rolls Royce SPEY RB (163) 511-8 series engines mounted on pylons 
extending from the aft fuselage, and it has a maximum takeoff weight of 
64,800 pounds. The Models G-1159A and G-1159B are slightly larger than 
the Model G-1159. These models are powered by two Rolls Royce SPEY RB 
(163-25) 511-8 series engines, and have a maximum takeoff

[[Page 76148]]

weight of 69,700 pounds. This series of airplanes operates with a 2-
pilot crew and can hold up to 19 passengers.

Type Certification Basis

    Under the provisions of 14 CFR Sec. 21.101, Duncan Aviation must 
show that the Gulfstream Models G-1159, G-1159A, and G-1159B airplanes, 
as modified, continue to meet the applicable provisions of the 
regulations incorporated by reference in Type Certificate No. A12EA, or 
the applicable regulations in effect on the date of application for the 
modification. 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:

1. For the Gulfstream Model G-1159 Airplane

    <bullet> CAR 4b dated December 31, 1953, including Amendments 4b-1 
through 4b-14;
    <bullet> Special Regulations SR422B and SR450A;
    <bullet> Sec. 25.1325 (effective 2/1/65);
    <bullet> Sec. 25.175 (effective 3/1/65) in lieu of 4b.155(b);
    <bullet> Sec. 36.1(c)(2) for airplane serial numbers (S/N) 1 
through 165 and 775 approved for a 62,000 lb. takeoff weight;
    <bullet> 14 CFR Part 36, Appendix C, for airplane S/N 166 through 
299, except 249, 252, and 775;
    <bullet> Special Conditions in Attachment A of FAA letter to 
Grumman, dated 9/27/65;
    <bullet> Exemption No. 695A, CAR 4b.437, ``Fuel Jettisoning 
System.''

2. For the Model G-1159A Airplane

    <bullet> 14 CFR part 25 effective February 1, 1965, and Amendments 
25-2 through 25-8, 25-10, 25-12, 25-16 through 25-22, 25-24, 25-26, 25-
27, 25-29 through 25-34, 25-37, 25-40 (as applicable to a new APU 
installation);
    <bullet> Sec. 25.329 of Part 25 dated February 1, 1965 (as applied 
to a new autopilot installation);
    <bullet> Sec. 25.581 (lightning protection) of Amendment 25-23;
    <bullet> Sec. 25.771, Amendment 25-4. (A lockable door is not 
required between the pilot and passenger compartments.);
    <bullet> Sec. 25.994 (crashworthiness fuel system components);
    <bullet> Sec. 25.1309 of Amendment 25-41;
    <bullet> Special Federal Aviation Regulation (SFAR) 27 through 
Amendment 2 (fuel venting emission);
    <bullet> 14 CFR part 36 through Amendment 36-8 (noise 
requirements);
    <bullet> Special Conditions contained in the FAA's letter to 
Grumman, dated 9/27/65, applicable to the Gulfstream Model G-1159 
airplane, are also applicable to the Gulfstream Model G-1159A airplane, 
except that reference to ``4b.450'' in the ``Cooling Systems'' special 
conditions is replaced by ``FAR 25.1043 contained in Part 25 of the 
FAR, effective 2/1/65;''
    <bullet> Special Conditions pertaining to dynamic gust loads 
contained in the enclosure to FAA AEA-212 letter, dated 7/22/80.

3. For the Model G-1159B

    <bullet> Fuselage, Empennage, Autopilot, and Noise:
--Car 4b, dated December 31, 1953, including Amendments 4b-1 through 
4b-14;
--CAR 4b.450, Cooling Systems;
--Special Regulation SR450A;
--Sec. 25.175 (effective 3/1/65) in lieu of CAR 4b.155(b);
--Sec. 25.771, Amendment 25-4. [A lockable door is not required between 
the pilot and passenger compartments.]
--Sec. 25.1325 (effective 2/1/65);
--Sec. 36.7(d)(3)(ii);
--Special Conditions in Attachment A of FAA letter to Grumman, dated 9/
27/65.
    <bullet> Wing Assembly, Landing Gear, Fuselage, and Empennage 
Modifications:
--14 CFR part 25, effective February 1, 1965, Amendments 25-2 through 
25-8, 25-10, 25-12, 25-16 through 25-22, 25-24, 25-26, except 
Sec. 25.1203(b)(3), 25-27, 25-29 through 25-31,25-34, 25-37, 25-40 (as 
applicable to a new APU installation);
--Sec. 25.581 (Lightning Protection) of Amendment 25-23;
--Sec. 25.771, Amendment 4 (A lockable door is not required between the 
pilot and passenger compartments.);
--Sec. 25.994 (Crashworthiness Fuel System Components);
--25.1309 of Amendment 25-41;
--Sec. 25.1329 (effective 2/1/65);
--SFAR 27 through Amendment 2 (Fuel Venting Emissions);
--Special Conditions contained in the FAA's letter to Grumman, dated 9/
27/65, applicable to Gulfstream Model G-1159 airplane, are also 
applicable to the Gulfstream Model G-1159B airplane;
--Special Conditions pertaining to dynamic gust loads, contained in the 
enclosure to FAA letter AEA-212, dated 7/22/80, is applicable to the 
Model G-1159B airplane.
    The special conditions approved in this document will form an 
additional part of the type certification basis for these airplanes.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25 as amended) do not contain adequate 
or appropriate safety standards for the Gulfstream Model G-1159, 11-
59A, and G-1159B airplanes modified by Duncan Aviation 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 
Sec. 11.49, 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 Duncan Aviation apply at a later date for a 
supplemental type certificate to modify any other model already 
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 Gulfstream Model G-1159, G-1159A, and G-1159B airplanes 
modified by Duncan Aviation will incorporate new avionics/electronics 
and electrical systems that will perform critical functions. These 
systems include a new flight display system and a new attitude heading 
reference system. These systems may be vulnerable to 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 avionics/electronics and electrical 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 Gulfstream Model G-1159, G-1159A, and G-
1159B airplanes modified by Duncan Aviation. These special conditions 
require that new avionics/electronics and electrical systems 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

[[Page 76149]]

the airplane, and the use of composite material in the airplane 
structure, the immunity of critical avionics/electronics and electrical 
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 paragraph 1. or, alternatively, 
paragraph 2., below:
    1. A minimum threat of 100 volts rms per meter 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.

Or

    2. A threat external to the airframe for both of the following 
field strengths for the frequency ranges indicated. Both peak and 
average field strength components from Table 1 are to be demonstrated.

                                 Table 1
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                                                          Field Strength
                                                            (volts per
                       Frequency                              meter)
                                                        ----------------
                                                          Peak   Average
------------------------------------------------------------------------
10 kHz--100 kHz........................................      50       50
100 kHz--500 kHz.......................................      50       50
500 kHz--2 MHz.........................................      50       50
2 MHz--30 MHz..........................................     100      100
30 MHz--70 MHz.........................................      50       50
70 MHz--100 MHz........................................      50       50
100 MHz--200 MHz.......................................     100      100
200 MHz--400 MHz.......................................     100      100
400 MHz--700 MHz.......................................     700       50
700 MHz--1 GHz.........................................     700      100
1 GHz--2 GHz...........................................    2000      200
2 GHz--4 GHz...........................................    3000      200
4 GHz--6 GHz...........................................    3000      200
6 GHz--8 GHz...........................................    1000      200
8 GHz--12 GHz..........................................    3000      300
12 GHz--18 GHz.........................................    2000      200
18 GHz--40 GHz.........................................     600      200
------------------------------------------------------------------------
  The field strengths are expressed in terms of peak of the root-mean-
            square (rms) over the complete modulation period.
------------------------------------------------------------------------

    The threat levels identified in Table 1 are the result of an FAA 
review of existing studies on the subject of HIRF, in light of the 
ongoing work of the Electromagnetic Effects Harmonization Working Group 
of the Aviation Rulemaking Advisory Committee.

Applicability

    As discussed above, these special conditions are applicable to the 
Gulfstream Model G-1159, G-1159A, and G-1159B 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. A12EA 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 novel or unusual design features 
on Gulfstream Model G-1159, G-1159A, and G-1159B airplanes modified by 
Duncan Aviation. 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.
    As stated previously, the substance of these special conditions has 
been subjected to the notice and comment period 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 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. 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 type certification basis for Gulfstream Aerospace Model G-1159, G-
1159A, and G-1159B airplanes modified by Duncan Aviation:
    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 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 November 29, 2000.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-31085 Filed 12-5-00; 8:45 am]
BILLING CODE 4910-13-U