[Federal Register Volume 63, Number 198 (Wednesday, October 14, 1998)]
[Rules and Regulations]
[Pages 55012-55015]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-27533]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE148, Special Condition 23-98-04-SC]
Special Conditions; Raytheon Aircraft Company Model 300 Airplane;
Protection of Systems for 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 to California Microwave,
Inc., 701 Wilson Point Road, Martin State Airport, Box 4, Baltimore,
Maryland 21220, for a Supplemental Type Certificate on the Raytheon
Model 300 airplane. This airplane will have novel and unusual design
features when compared to the state of technology envisaged in the
applicable airworthiness standards. These novel
[[Page 55013]]
and unusual design features include the installation of an electronic
flight instrument system (EFIS) for which the applicable regulations do
not contain adequate or appropriate airworthiness 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 provided by the applicable
airworthiness standards.
DATES: The effective date of these special conditions is October 2,
1998. Comments must be received on or before November 13, 1998.
ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation
Administration, Regional Counsel, ACE-7, Attention: Rules Docket Clerk,
Docket No. CE148, Room 1558, 601 East 12th Street, Kansas City,
Missouri 64106. All comments must be marked: Docket No. CE148. 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: Ervin Dvorak, Aerospace Engineer,
Standards Office (ACE-110), Small Airplane Directorate, Aircraft
Certification Service, Federal Aviation Administration, 601 East 12th
Street, Kansas City, Missouri 64106; telephone (816) 426-6941.
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
Interested persons are invited to submit 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. 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 this notice must include a self-
addressed, stamped postcard on which the following statement is made:
``Comments to Docket No. CE148.'' The postcard will be date stamped and
returned to the commenter.
Background
On April 23, 1998, California Microwave, Inc., 701 Wilson Point
Road, Martin State Airport, Box 4, Baltimore, Maryland 21220, applied
to the FAA for a Supplemental Type Certificate (STC) for a modification
on a Raytheon Model 300 airplane. The proposed modification
incorporates a novel or unusual design feature, such as digital
avionics consisting of an EFIS, that is vulnerable to HIRF external to
the airplane.
Type Certification Basis
Under the provisions of 14 CFR 21.101, California Microwave, Inc.
must show that the Raytheon Model 300 airplane meets the applicable
provisions of the following:
The type certification basis as modified by this STC to add an EFIS
on the Raytheon Model 300 airplane is given by the following:
Special Federal Aviation Regulation (SFAR) 41C, effective September
13, 1982, see NOTE 7 or 11 (300 only); 14 CFR part 23, effective
February 1, 1965, through Amendment 23-9; Amendment 23-11; Amendment
23-14, Secs. 23.143(a). 23.145(d), 23.153, 23.161(c)(3), 23.173(a),
23.175, 23.427, 23.441, and 23.445; Amendment 23-15, Sec. 23.951(c) and
Sec. 23.997(d); Amendment 23-23, Sec. 23.1545(a); Amendment 23-26,
Secs. 23.967 and 23.1305(n); Special Conditions No. 23-47-CE-5,
including Amendment Nos.. 1, 2, 3 dated November 15, 1982, and 4 dated
October 17, 1986; 14 CFR part 25, Sec. 25.929, effective February 1,
1965, Amendment 25-23, Sec. 25.1419; Amendment 25-41, Sec. 25.831(d);
14 CFR part 36, through Amendment 36-10, and SFAR 27, through Amendment
27-4; Sec. 23.1301 of Amendment 23-20; Secs. 23.1309, 23.1311, and
23.1321 of Amendment 23-49; and Sec. 23.1322 of Amendment 23-43;
exemptions, if any; and the special conditions adopted by this
rulemaking action. Compliance with ice protection has been demonstrated
in accordance with Sec. 25.1419 when ice protection equipment is
installed in accordance with the Equipment List.
If the Administrator finds that the applicable airworthiness
regulations, 14 CFR part 23, do not contain adequate or appropriate
safety standards for the Raytheon Model 300 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 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 California Microwave, Inc. modified Raytheon Model 300 airplane
will incorporate the following novel or unusual design features:
Installation of an EFIS for which the airworthiness standards do not
contain adequate or appropriate safety standards for protection from
the effects of HIRF.
Discussion
The FAA may issue and amend special conditions, as necessary, as
part of the type certification basis if the Administrator finds that
the airworthiness standards, designated according to Sec. 21.101(b), do
not contain adequate or appropriate safety standards because of novel
or unusual design features of an airplane. 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 are normally issued according to Sec. 11.49, after public
notice, as required by Secs. 11.28 and 11.29(b), effective October 14,
1980, and become a part of the type certification basis in accordance
with Sec. 21.101(b)(2).
California Microwave, Inc. plans to incorporate certain novel and
unusual design features into an airplane for which the airworthiness
standards do not contain adequate or appropriate safety standards for
protection from the effects of HIRF. These features include an EFIS,
which is susceptible to the HIRF environment, that was not envisaged by
the existing regulations for this type of airplane.
[[Page 55014]]
Protection of Systems From High Intensity Radiated Fields (HIRF)
Recent advances in technology have given rise to the application in
aircraft designs of advanced EFIS that perform functions required for
continued safe flight and landing. Due to the use of sensitive solid
state advanced components in analog and digital electronics circuits,
these advanced systems are readily responsive to the transient effects
of induced electrical current and voltage caused by the HIRF. The HIRF
can degrade EFIS performance by damaging components or upsetting system
functions.
Furthermore, the HIRF environment has undergone a transformation
that was not foreseen when the current requirements were developed.
Higher energy levels are radiated from transmitters that are used for
radar, radio, and television. Also, the number of transmitters has
increased significantly. There is also uncertainty concerning the
effectiveness of airframe shielding for HIRF. Furthermore, coupling to
cockpit-installed equipment through the cockpit window apertures is
undefined.
The combined effect of the technological advances in airplane
design and the changing environment has resulted in an increased level
of vulnerability of EFIS required for the continued safe flight and
landing of the airplane. Effective measures against the effects of
exposure to HIRF must be provided by the design and installation of
these systems. The accepted maximum energy levels in which civilian
airplane system installations must be capable of operating safely are
based on surveys and analysis of existing radio frequency emitters.
These special conditions require that the airplane be evaluated under
these energy levels for the protection of the EFIS and its associated
wiring harness. These external threat levels, which are lower than
previously required values, are believed to represent the worst case to
which an airplane would be exposed in the operating environment.
These special conditions require qualification of systems that
perform critical functions, as installed in aircraft, to the defined
HIRF environment in paragraph 1 or, as an option to a fixed value using
laboratory tests, in paragraph 2, as follows:
(1) The applicant may demonstrate that the operation and
operational capability of the installed electrical and electronic
systems that perform critical functions are not adversely affected when
the aircraft is exposed to the HIRF environment defined as follows:
------------------------------------------------------------------------
Field strength (volts per
meter)
Frequency -------------------------------
Peak Average
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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 root-mean-square
(rms) values.
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or,
(2) The applicant may demonstrate by a system test and analysis
that the electrical and electronic systems that perform critical
functions can withstand a minimum threat of 100 volts per meter, peak
electrical field strength, from 10 kHz to 18 GHz. When using this test
to show compliance with the HIRF requirements, no credit is given for
signal attenuation due to installation.
A preliminary hazard analysis must be performed by the applicant,
for approval by the FAA, to identify electrical and/or electronic
systems that perform critical functions. The term critical means those
functions whose failure would contribute to, or cause, a failure
condition that would prevent the continued safe flight and landing of
the airplane. The systems identified by the hazard analysis that
perform critical functions are candidates for the application of HIRF
requirements. A system may perform both critical and non-critical
functions. Primary EFIS, and their associated components, perform
critical functions such as attitude, altitude, and airspeed indication.
The HIRF requirements apply only to critical functions.
Compliance with HIRF requirements may be demonstrated by tests,
analysis, models, similarity with existing systems, or any combination
of these. Service experience alone is not acceptable since normal
flight operations may not include an exposure to the HIRF environment.
Reliance on a system with similar design features for redundancy as a
means of protection against the effects of external HIRF is generally
insufficient since all elements of a redundant system are likely to be
exposed to the fields concurrently.
Applicability
As discussed above, these special conditions are applicable to the
Raytheon Model 300 airplane. Should California Microwave, Inc. apply at
a later date for a supplemental type certificate to modify any other
model included on the same type certificate 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 novel or unusual design features
on one model Raytheon Model 300 airplane. It is not a rule of general
applicability and
[[Page 55015]]
affects only the applicant who 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 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 23
Aircraft, Aviation safety, Signs and symbols.
Citation
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113 and 44701; 14 CFR 21.16 and
21.101; and 14 CFR 11.28 and 11.49.
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 Raytheon Model 300 airplane modified
by California Microwave, Inc. to add an EFIS.
1. Protection of Electrical and Electronic Systems from High
Intensity Radiated Fields (HIRF). Each system that performs critical
functions must be designed and installed to ensure that the operation,
and operational capabilities of these systems to perform critical
functions, are not adversely affected when the airplane is exposed to
high intensity radiated electromagnetic fields external to the
airplane.
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 Kansas City, Missouri on October 2, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-27533 Filed 10-13-98; 8:45 am]
BILLING CODE 4910-13-P
