[Federal Register: November 13, 2002 (Volume 67, Number 219)]
[Rules and Regulations]
[Page 68753-68755]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13no02-1]
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Rules and Regulations
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[[Page 68753]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM239; Special Conditions No. 25-223-SC
Special Conditions: Embraer Model 170-100 and 170-200 Airplanes;
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 Embraer Model 170-
100 and 170-200 airplanes. These airplanes will have novel or unusual
design features when compared to the state of technology envisioned in
the airworthiness standards for transport category airplanes. The
airplane design includes an electronic flight control system as well as
advanced avionics for the display and control of critical airplane
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.
Additional special conditions will be issued for other novel or unusual
design features of Embraer Model 170-100 and 170-200 airplanes.
DATES: The effective date of these special conditions is November 1,
2002. Comments must be received on or before December 13, 2002.
ADDRESSES: Comments on these special conditions may be mailed in
duplicate to: Federal Aviation Administration, Transport Airplane
Directorate, Attention: Rules Docket (ANM-113), Docket No. NM239, 1601
Lind Avenue SW., Renton, Washington 98055-4056; or delivered in
duplicate to the Transport Airplane Directorate at the above address.
All comments must be marked: Docket No. NM239. Comments may be
inspected in the Rules Docket weekdays, except Federal holidays,
between 7:30 a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT: Tom Groves, FAA, International Branch,
ANM-116, Transport Airplane Directorate, Aircraft Certification
Service, 1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone
(425) 227-1503; facsimile (425) 227-1149.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA has determined that notice and opportunity for prior public
comment hereon is unnecessary as 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; however, the FAA invites interested
persons to participate in this rulemaking by submitting such written
comments, data, or views, as they may desire. 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
concerning these special conditions. The docket is available for public
inspection 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 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 in light of 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 May 20, 1999, Embraer applied for a type certificate for its new
Model 170 airplane. Two basic versions of the Model 170 are included in
the application. The Model 170-100 airplane is a 69-78 passenger twin-
engine regional jet with a maximum takeoff weight of 81,240 pounds. The
Model 170-200 is a lengthened fuselage derivative of the 170-100.
Passenger capacity for the Model 170-200 is increased to 86, and
maximum takeoff weight is increased to 85,960 pounds. Embraer Model
170-100 and 170-200 airplanes will include an electronic flight control
system as well as advanced avionics for the display and control of
critical airplane functions. These systems may be vulnerable to high-
intensity radiated fields (HIRF) external to the airplane.
Type Certification Basis
Under the provisions of 14 CFR 21.17, Embraer must show that Model
170-100 and 170-200 airplanes meet the applicable provisions of 14 CFR
part 25, as amended by Amendments 25-1 through 25-98.
If the Administrator finds that the applicable airworthiness
regulations (i.e., part 25, as amended) do not contain adequate or
appropriate safety standards for Embraer Model 170-100 and 170-200
airplanes because of a novel or unusual design feature, special
conditions are prescribed under the provisions of Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, Embraer Model 170-100 and 170-200 airplanes 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, and the FAA
must issue a finding of regulatory adequacy pursuant to Sec. 611 of
Pub. L. 93-574, the ``Noise Control Act of 1972.''
Special conditions, as defined in 14 CFR 11.19, are issued in
accordance with Sec. 11.38, and become part of the airplane's type
certification basis in accordance with Sec. 21.101(b)(2), Amendment
21-69, effective September 16, 1991.
[[Page 68754]]
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), Amendment 21-
69, effective September 16, 1991.
Novel or Unusual Design Features
As noted earlier, Embraer Model 170-100 and 170-200 airplanes will
include an electronic flight control system as well as advanced
avionics for the display and control of critical airplane functions.
These systems may be vulnerable to high-intensity radiated fields
(HIRF) external to the airplane. The current airworthiness standards of
part 25 do not contain adequate or appropriate safety standards that
address the protection of this equipment from the adverse effects of
HIRF. Accordingly, these systems are considered to be novel or unusual
design features.
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 that is equivalent to
that intended by the regulations incorporated by reference, special
conditions are needed for the Embraer Model 170-100 and 170-200
airplanes. These special conditions require that 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 and the advent of space and satellite communications
coupled with electronic command and control of the airplane, 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 in accordance with 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. 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 field strengths
indicated in the table below for the frequency ranges indicated. Both
peak and average field strength components from the table are to be
demonstrated.
------------------------------------------------------------------------
Field strength
(volts per meter)
Frequency ---------------------
Peak Average
------------------------------------------------------------------------
10 kHz-100kHz..................................... 50 50
100 kHz-500 kHz................................... 50 50
500 kHz-2 MHz..................................... 50 50
2 MHz 2-30 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 above 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
Embraer Model 170-100 and 170-200 airplanes. 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, these
special conditions would apply to that model as well, under the
provisions of Sec. 21.101(a)(2), Amendment 21-69, effective September
16, 1991.
Conclusion
This action affects only certain novel or unusual design features
of the Embraer Model 170-100 and 170-200 airplanes. It is not a rule of
general applicability, and it affects only the applicant which applied
to the FAA for approval of these features on the airplane.
The substance of these special conditions has been subjected to the
notice and comment procedure in several prior instances and has been
derived without substantive change from those previously issued. The
FAA has determined that prior public notice and comment are
unnecessary, and that 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 Embraer Model 170-100 and 170-200
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.
[[Page 68755]]
Issued in Renton, Washington, on November 1, 2002.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 02-28824 Filed 11-12-02; 8:45 am]
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