[Federal Register Volume 61, Number 65 (Wednesday, April 3, 1996)]
[Proposed Rules]
[Pages 14684-14685]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-8037]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 61, No. 65 / Wednesday, April 3, 1996 /
Proposed Rules
[[Page 14684]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM-123; Notice No. SC-96-2-NM]
Special Conditions: Embraer (Brazil) Aircraft Corporation Model
EMB-145 Airplane; High-Intensity Radiated Fields
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed special conditions.
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SUMMARY: This document proposes special conditions for the Embraer
Model EMB-145 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 proposed 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: Comments must be received on or before May 20, 1996.
ADDRESSES: Comments on this proposal may be mailed in duplicate to:
Federal Aviation Administration, Office of the Assistant Chief Counsel,
Attn: Rules Docket (ANM-7), Docket No. NM-123, 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-123. 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:
Gerry Lakin, FAA, Standardization Branch, ANM-113, Transport Airplane
Directorate, Aircraft Certification Service, 1601 Lind Avenue SW.,
Renton, Washington, 98055-4056; telephone (206) 227-1187; facsimile
(206) 227-1149.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of
these proposed special conditions by submitting such written data,
views, or arguments as they may desire. Communications should identify
the regulatory docket or notice 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
before further rulemaking action is taken on these proposals. The
proposals contained in this notice may be changed in light of 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 notice must submit with those
comments a self-addressed, stamped postcard on which the following
statement is made: ``Comments to Docket No. NM-123.'' The postcard will
be date stamped and returned to the commenter.
Background
On August 30, 1989, Embraer Aircraft Corporation, Caixa Postal 343,
12227-901 Sao Jose dos Campos, Sao Paulo SP Brasil, applied for a new
type certificate in the transport airplane category for the Model EMB-
145 airplane. The EMB-145 is a T-tail, low swept wing, small transport
airplane powered by two Allison GMA-3007A turbofan engines mounted on
pylons extending from the aft fuselage. Each engine will be capable of
delivering 7,040 pounds thrust. The flight controls will be powered and
capable of manual reversion. The airplane has a seating capacity of up
to 50 passengers, and a maximum takeoff weight of 42,328 pounds.
Type Certification Basis
Under the provisions of Sec. 21.17 of the FAR, Embraer must show,
except as provided in Sec. 25.2, that the Model EMB-145 meets the
applicable provisions of part 25, effective February 1, 1965, as
amended by Amendments 25-1 through 25-75. In addition, the proposed
certificate basis for the Model EMB-145 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. The special conditions
that may be developed as a result of this notice will form an
additional part of the type of certification basis. In addition, the
certification basis may include other special conditions that are not
relevant to these proposed special conditions.
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 Embraer Model EMB-145 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. 21.17(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, 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 EMB-145 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.
[[Page 14685]]
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 Embraer Model EMB-145, which would
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.
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 paragraphs 1 or 2 below:
1. A minimum threat of 100 volts per meter peak electric field
strength from 10KHz to 18GHz.
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)
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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
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As discussed above, the proposed special conditions would be
applicable initially to the Embraer Model EMB-145. Should Embraer apply
at a later date for a change to the type certificate to include another
model incorporating 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 design features on the Embraer
Model EMB-145 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, 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 Proposed Special Conditions
Accordingly, the Federal Aviation Administration (FAA) proposes the
following special conditions as part of the type certification basis
for the Embraer Model EMB-145 series 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 March 25, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-8037 Filed 4-2-96; 8:45 am]
BILLING CODE 4910-13-M