[Federal Register: January 10, 2007 (Volume 72, Number 6)]
[Rules and Regulations]
[Page 1137-1139]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr10ja07-3]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM363; Special Conditions No. 25-344-SC]
Special Conditions: Gulfstream Aerospace Corporation Model G-
1159A Airplanes; High-Intensity Radiated Fields (HIRF)
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
-----------------------------------------------------------------------
SUMMARY: The FAA issues these special conditions for a Gulfstream
Aerospace Corporation Model G-1159A airplane modified by AeroMech
Incorporated. This modified airplane will have a novel or unusual
design feature when compared to the state of technology envisioned in
the airworthiness standards for transport category airplanes. The
modification incorporates the installation of Innovative Solutions and
Support integrated air data display units (ADDU). These systems 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 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 29,
2006. We must receive your comments on or before February 9, 2007.
ADDRESSES: You may mail or deliver comments on these special conditions
in duplicate to: Federal Aviation Administration, Transport Airplane
Directorate, Attention: Rules Docket (ANM-113), Docket No. NM363, 1601
Lind Avenue, SW., Renton, Washington 98057-3356. You must mark your
comments Docket No. NM363.
FOR FURTHER INFORMATION CONTACT: Greg Dunn, FAA, Airplane and Flight
Crew Interface Branch, ANM-111, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind Avenue, SW., Renton,
Washington 98057-3356; telephone (425) 227-2799; facsimile (425) 227-
1320.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA has determined that notice and opportunity for prior public
comment for these special conditions is impracticable because these
procedures would significantly delay certification and 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. We therefore
find that good cause exists for making these special conditions
effective upon issuance. However, we invite interested persons to take
part in this rulemaking by submitting written comments. The most
helpful comments reference a specific portion of the special
conditions, explain the reason for any recommended change, and include
supporting data. We ask that you send us two copies of written
comments.
We will file in the docket all comments we receive, as well as a
report summarizing each substantive public contact with FAA personnel
about these special conditions. You may inspect the docket before and
after the comment closing date. If you wish to review the docket in
person, go to the address in the ADDRESSES section of this preamble
between 7:30 a.m. and 4 p.m., Monday through Friday, except Federal
holidays.
We will consider all comments we receive on or before the closing
date for
[[Page 1138]]
comments. We will consider comments filed late if it is possible to do
so without incurring expense or delay. We may change these special
conditions based on the comments we receive.
If you want the FAA to acknowledge receipt of your comments on
these special conditions, include with your comments a pre-addressed,
stamped postcard on which the docket number appears. We will stamp the
date on the postcard and mail it back to you.
Background
On September 29, 2006, AeroMech Incorporated, 1616 Hewitt Avenue,
Suite 312, Everett, Washington 98201, applied for a supplemental type
certificate (STC) to modify a Gulfstream Aerospace Corporation model G-
1159A airplane. The Gulfstream Aerospace Corporation Model G-1159A
airplane is a small transport category airplane powered by two turbine
engines. It operates with a 2-pilot crew and can seat up to 15
passengers. The modification incorporates the installation of
Innovative Solutions and Support integrated air data display units.
These systems have a potential to be vulnerable to high-intensity
radiated fields (HIRF) external to the airplane.
Type Certification Basis
Under the provisions of 14 CFR 21.101, AeroMech Incorporated must
show that Gulfstream Aerospace Corporation Model G-1159A airplane, as
changed, continues 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
change. The regulations incorporated by reference in the type
certificate are commonly referred to as the ``original type
certification basis.'' The specific regulations are 14 CFR part 25 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 25-34, 25-37, 25-40 (as
applicable to a new APU installation); Sec. 25.1309 as amended by
Amendment 25-41, and Sec. 25.1329 (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;
and Special part 27, as amended by Amendment 27-2 (fuel venting
emission). 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-1159A
airplane, except that reference to Civil Air Regulations 4b.450 in the
``Cooling Systems'' special conditions is replaced by Sec. 25.1043,
effective February 1, 1965. In addition, the special conditions
pertaining to dynamic gust loads contained in the FAA AEA-212 letter
dated July 22, 1980.
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 Aerospace Corporation
Model G-1159A airplane because of a novel or unusual design feature,
special conditions are prescribed under Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, Gulfstream Aerospace Corporation Model G-1159A airplane
must comply with the fuel vent and exhaust emission requirements of 14
CFR part 34 and the noise certification requirements of 14 CFR part 36.
The FAA issues special conditions, as defined in Sec. 11.19, under
Sec. 11.38, and they become part of the type certification basis under
the provisions of Sec. 21.101.
Novel or Unusual Design Features
As noted earlier, Gulfstream Aerospace Corporation G-1159A airplane
modified by AeroMech Incorporated will incorporate Innovative Solutions
and Support integrated air data display units that will perform
critical functions. These systems may be vulnerable to high-intensity
radiated fields external to the airplane. Current airworthiness
standards of part 25 do not contain adequate or appropriate safety
standards for protecting this equipment from adverse effects of HIRF.
So this system is considered to be a novel or unusual design feature.
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 Aerospace Corporation G-1159A
airplane modified by AeroMech Incorporated. 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 because of HIRF.
High-Intensity Radiated Fields (HIRF)
High-power radio frequency transmitters for radio, radar,
television, and satellite communications can adversely affect operation
of airplane electric and electronic systems. Therefore, the immunity of
critical avionics/electronics and electrical systems to HIRF must be
established.
Based on surveys and analysis of existing HIRF emitters, an
adequate level of protection exists when airplane system immunity is
demonstrated when exposed to the HIRF environments in either paragraph
1 OR 2 below:
1. A minimum threat of 100 volts rms (root-mean-square) per meter
electric field strength from 10 KHz to 18 GHz.
a. System elements and their associated wiring harnesses must be
exposed to the environment without benefit of airframe shielding.
b. Demonstration of this level of protection is established through
system tests and analysis.
2. An environment external to the airframe of the field strengths
shown in the table below for the frequency ranges indicated. Immunity
to both peak and average field strength components from the table must
be demonstrated.
------------------------------------------------------------------------
Field strength
(volts per meter)
Frequency --------------------
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 environmental levels identified above are the result of an FAA
review of existing studies on the subject of HIRF and of the work of
the Electromagnetic Effects Harmonization Working Group of the Aviation
Rulemaking Advisory Committee.
Applicability
These special conditions are applicable to a Gulfstream Aerospace
[[Page 1139]]
Corporation Model G-1159A airplane modified by AeroMech Incorporated.
Should AeroMech Incorporated apply at a later date for a supplemental
type certificate to modify any other similar model included on Type
Certificate No. A12EA to incorporate the same or similar novel or
unusual design feature, these special conditions would apply to that
model as well under Sec. 21.101.
Conclusion
This action affects only certain novel or unusual design features
on a Gulfstream Aerospace Corporation Model G-1159A airplane modified
by AeroMech Incorporated. 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.
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
Therefore, under 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 Aerospace
Corporation Model G-1159A airplane modified by AeroMech Incorporated.
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 December 29, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-197 Filed 1-9-07; 8:45 am]
BILLING CODE 4910-13-P