[Federal Register Volume 60, Number 167 (Tuesday, August 29, 1995)]
[Rules and Regulations]
[Pages 44748-44749]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-21333]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM-109; Special Conditions No. 25-NM-105]
Special Condition: Gulfstream Aerospace Corporation, Model
Gulfstream V, High-Intensity Radiated Fields
agency: Federal Aviation Administration, DOT.
action: Final special conditions.
-----------------------------------------------------------------------
summary: These special conditions are for the Gulfstream Model
Gulfstream V airplane. This new airplane will utilize new avionics/
electronic systems that provide critical data to the flightcrew. 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: September 28, 1995.
for further information contact: Gerald Lakin, FAA, Standardization
Branch, ANM-113, Transport Airplane Directorate, Aircraft Certification
Service, 1601 Lind Avenue SW., Renton, Washington 98055-4056, (206)
227-1187.
SUPPLEMENTARY INFORMATION:
Background
On February 26, 1992, Gulfstream Aerospace Corporation, P.O. Box
2206, Savannah, GA 31402-2206, applied for an amended type certificate
in the transport airplane category for the Model Gulfstream V airplane.
The Gulfstream V is a T-tail, low swept wing, business jet airplane
powered by two Rolls-Royce BR710-48 turbofan engines mounted on pylons
extending from the aft fuselage. Each engine will be capable of
delivering 14,750 pounds thrust. The flight controls will be powered
and capable of manual reversion. The airplane has a seating capacity of
up to nineteen passengers, and a maximum takeoff weight of 89,000
pounds.
Type Certification Basis
Under the provisions of Sec. 21.101 of the FAR, Gulfstream must
show, except as provided in Sec. 25.2, that the Model Gulfstream V
meets the applicable provisions of part 25, effective February 1, 1965,
as amended by Amendments 25-1 through 25-81. In addition, the proposed
certification basis for the Model Gulfstream V includes part 34,
effective September 10, 1990, plus any amendments in effect at the time
of certification; and part 36, effective December 1, 1969, as amended
by Amendment 36-1 through the amendment in effect at the time of
certification. No exemptions are anticipated. These special conditions
form an additional part of the type certification basis. In addition,
the certification basis may include other special conditions that are
not relevant to these special conditions.
[[Page 44749]]
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 V 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. 21.101(b)(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 Gulfstream V incorporates new avionic/electronic
installations, including a digital Electronic Flight Instrument System
(EFIS), Air Data System, Attitude and Heading Reference System (AHRS),
Navigation and Communication System, Autopilot System, and a Full
Authority Digital Engine Control (FADEC) system that controls critical
engine parameters. These systems 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, special
conditions are issued for the Gulfstream V which require that new
technology electrical and electronic systems, such as the EFIS, FADEC,
AHRS, etc., 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
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 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 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-2000 KHz.................................. 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-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, these special conditions would be applicable
initially to the Model Gulfstream V. Should Gulfstream apply at a later
date for a change to the type certificate 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 95-3-NM for the
Gulfstream Aerospace Corporation, Model Gulfstream V, was published in
the Federal Register on June 1, 1995 (60 FR 28550). One comment was
received. The commenter states that the presently proposed
certification basis for the Gulfstream V is part 25 of the FAR as
amended by Amendments 25-1 through 25-81 instead of through 25-75 as
stated in the notice. The FAA agrees with the commenter and has
incorporated the change in this document.
Conclusion
This action affects certain design features only on the Gulfstream
V 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 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 Special Conditions
Accordingly, the following special conditions are issued as part of
the type certification basis for the Gulfstream Aerospace Corporation
Model Gulfstream V airplanes.
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 August 18, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service, ANM-100.
[FR Doc. 95-21333 Filed 8-28-95; 8:45 am]
BILLING CODE 4910-13-M
