[Federal Register: October 8, 2003 (Volume 68, Number 195)]
[Rules and Regulations]
[Page 58009-58011]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08oc03-1]
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Rules and Regulations
Federal Register
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[[Page 58009]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE198, Special Condition 23-137-SC]
Special Conditions; Aero Vodochody Ae-270 Propjet; 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 for the Aero Vodochody Ae-
270 Propjet 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
system (EFIS) displays made by Chelton Flight Systems 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 the airworthiness standards applicable to these
airplanes.
DATES: The effective date of these special conditions is September 16,
2003. Comments must be received on or before November 7, 2003.
ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation
Administration, Regional Counsel, ACE-7, Attention: Rules Docket Clerk,
Docket No. CE198, Room 506, 901 Locust, Kansas City, Missouri 64106.
All comments must be marked: Docket No. CE198. 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: Wes Ryan, Aerospace Engineer,
Standards Office (ACE-110), Small Airplane Directorate, Aircraft
Certification Service, Federal Aviation Administration, 901 Locust,
Room 301, Kansas City, Missouri 64106; telephone (816) 329-4127.
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. CE198.'' The postcard will be date stamped and
returned to the commenter.
Background
On June 8, 1998, Aero Vodochody a.s. in the Czech Republic made
application for a new Type Certificate for the Ae-270 Propjet. This
application date has been extended and revised to September 10, 2002.
As part of the FAA validation process for issuance of a Type
Certificate in the United States for foreign applicants, the FAA is
issuing these special conditions to address special certification
review items for novel and unusual features of the Ae-270 Propjet. The
proposed type design incorporates a novel or unusual design feature,
the Chelton Flight Systems Synthetic Vision System (SVS) Primary Flight
Display (PFD), that is vulnerable to HIRF external to the airplane.
Type Certification Basis
Under the provisions of 14 CFR part 21, Sec. 21.17, Aero Vodochody
a.s, must show that the Ae-270 Propjet aircraft meets the following
provisions, or the applicable regulations in effect on the date of
application for the Ae-270 Propjet: 14 CFR part 23, Amendment 55,
effective March 1, 2002; exemptions, if any; and the special conditions
adopted by this rulemaking action.
Discussion
If the Administrator finds that the applicable airworthiness
standards 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.
Special conditions, as appropriate, as defined in Sec. 11.19, are
issued in accordance with Sec. 11.38 after public notice 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 applicant apply for a supplemental type
certificate to modify any other model already included on the same type
certificate 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.
Novel or Unusual Design Features
Aero Vodochody a.s. 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 EFIS, which are
susceptible to the HIRF environment, that were not envisaged
[[Page 58010]]
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 previous 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 below:
------------------------------------------------------------------------
Field strength
(volts per meter)
Frequency ---------------------
Peak Average
------------------------------------------------------------------------
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
------------------------------------------------------------------------
Note: The field strengths are expressed in terms of peak root-mean-
square (rms) values.
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,
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 either electrical 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 Aero
Vodochody a.s. in the Czech Republic. Should Aero Vodochody a.s. apply
at a later date for a supplemental type certificate to modify any other
model on the same 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.
[[Page 58011]]
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.
Citation
0
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
Sec. 21.17; and 14 CFR 11.38 and 11.19.
The Special Conditions
0
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 Aero Vodochody Ae-270 Propjet
airplane with the Chelton Flight Systems SVS PFD.
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 September 16, 2003.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 03-25425 Filed 10-7-03; 8:45 am]
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