[Federal Register Volume 63, Number 248 (Monday, December 28, 1998)]
[Rules and Regulations]
[Pages 71369-71371]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-34162]
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Rules and Regulations
Federal Register
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Federal Register / Vol. 63, No. 248 / Monday, December 28, 1998 /
Rules and Regulations
[[Page 71369]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE150, Special Condition 23-094-SC]
Special Conditions; Raytheon Aircraft Company, Raytheon Model 390
Airplane: Protection of Systems From 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 Raytheon Aircraft
Company, 9709 East Central, Wichita, Kansas 67201-0085 for a type
certificate on the Raytheon Model 390 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 and unusual design features include the installation of
electronic flight instrument systems (EFIS) displays 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 December 28,
1998. Comments must be received on or before January 27, 1999.
ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation
Administration, Office of the Assistant Chief Counsel, ACE-7,
Attention: Rules Docket Clerk, Docket No. CE150, Room 1558, 601 East
12th Street, Kansas City, Missouri 64106. All comments must be marked:
Docket No. CE150. 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 CE150.'' The postcard will be date stamped and returned
to the commenter.
Background
On August 1, 1995, Raytheon Aircraft Company (then Beech Aircraft
Corporation) made application to the FAA for a type certificate for the
Raytheon Model 390 airplane. The proposed configuration 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 part 21, Sec. 21.17, Raytheon
Aircraft Company must show that the Raytheon Model 390 meets the
applicable provisions of the following type certification basis for the
Raytheon Model 390 airplane:
Federal Aviation Regulations part 23 effective February 1, 1965, as
amended by Amendments 23-1 through 23-52, with Special Conditions to
replace much of Subparts B and G; Federal Aviation Regulations part 34
effective September 10, 1990, as amended by the amendment in effect on
the date of certification; Federal Aviation Regulations part 36
effective December 1, 1969, as amended by amendment 36-1 through the
amendment in effect on the day of certification; The Noise Control Act
of 1972; Special Conditions for such items as Protection from High
Intensity Radiated Fields (HIRF), Takeoff Out of Trim Warning, and
Engine Fire Extinguishing System; and Exemption No. 6558, which was
granted December 12, 1996, pertaining to airplane landing gear loads.
Novel or Unusual Design Features
The Raytheon Model 390 will incorporate the following novel or
unusual design features: Installation of EFIS for which the
airworthiness standards do not contain adequate or appropriate safety
standards for protection from the effects of HIRF.
Discussion
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 390 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. 21.17(a)(2).
Special conditions are initially applicable to the model for which
they
[[Page 71370]]
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).
Raytheon Aircraft Company 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 electronic
systems, which are susceptible to the HIRF environment, that were not
envisaged by the existing regulations for this type of airplane.
Protection of Systems From High Intensity Radiated Fields (HIRF)
Recent advances in technology have given rise to the application in
aircraft designs of advanced electrical and electronic systems 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 electronic systems
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 electrical and electronic systems 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
electronic system 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/Meter
------------------------------------------------------------------------
Frequency Peak Average
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10-100 KHz.......................................... 50 50
100-500 KHz......................................... 60 60
500-2000 KHz........................................ 70 70
2-30 MHz............................................ 200 200
30-70 MHz........................................... 30 30
70-100 MHz.......................................... 30 30
100-200 MHz......................................... 150 33
200-400 MHz......................................... 70 70
400-700 MHz......................................... 4020 935
700-1000 MHz........................................ 1700 170
1-2 GHz............................................. 5000 990
2-4 GHz............................................. 6680 840
4-6 GHz............................................. 6850 310
6-8 GHz............................................. 3600 670
8-12 GHz............................................ 3500 1270
12-18 GHz........................................... 3500 360
18-40 GHz........................................... 2100 750
------------------------------------------------------------------------
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 electronic flight display systems, 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 390. Should Raytheon Aircraft Company apply at a later
date for a supplemental type certificate or amended type certificate to
modify any other model that may be included on this type certificate to
incorporate 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 of airplane. 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.
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
[[Page 71371]]
Citation
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113 and 44701; 14 CFR part 21,
Secs. 21.16 and 21.17; and 14 CFR part 11, Secs. 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 the Raytheon Aircraft Company Model
390 airplane.
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 operations,
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 December 11, 1998.
Michael K. Dahl,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-34162 Filed 12-24-98; 8:45 am]
BILLING CODE 4910-13-P