[Federal Register: July 19, 2007 (Volume 72, Number 138)]
[Rules and Regulations]
[Page 39555-39557]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19jy07-1]
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Rules and Regulations
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[[Page 39555]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE271, Special Condition 23-211-SC]
Special Conditions; Symphony Aircraft Industries, Inc. Model
SA160; Protection of Systems for High Intensity Radiated Fields (HIRF)
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued to Symphony Aircraft
Industries, Inc. for a type design change to the SA160 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
(Entegra Avionics Suite) manufactured by Avidyne Corporation 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 July 6, 2007.
Comments must be received on or before August 20, 2007.
ADDRESSES: Mail two copies of your comments to: Federal Aviation
Administration, Regional Counsel, ACE-7, Attention: Rules Docket Clerk,
Docket No. CE271, Room 506, 901 Locust, Kansas City, Missouri 64106.
All comments must be marked: Docket No. CE271. You may inspect comments
in the Rules Docket weekdays, except Federal holidays, between 7:30
a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT: Jim Brady, Aerospace Engineer,
Standards Office (ACE-111), Small Airplane Directorate, Aircraft
Certification Service, Federal Aviation Administration, 901 Locust,
Room 301, Kansas City, Missouri 64106; telephone (816) 329-4132.
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
We invite interested persons to take part in this rulemaking by
sending written data, views, or comments. Identify the regulatory
docket or notice number and submit two copies to the address specified
above. The most helpful comments reference a specific portion of the
special conditions, explain the reason for any recommended change, and
include supporting data.
We will file in the docket all comments we receive on or before the
closing date as well as a report summarizing each substantive public
contact with FAA personnel about these special conditions. All comments
received will be available in the Rules Docket for examination by
interested persons, both before and after the closing date for
comments.
We will consider all comments we receive by the closing date for
comments. We will consider comments filed late if it is possible to do
so without incurring expense or delay. Based on the comments we
receive, we may change these special conditions.
If you want the FAA to acknowledge receipt of your comments,
include a self-addressed, stamped postcard on which the following
statement is made: ``Comments to Docket No. CE271.'' The postcard will
be date stamped and we will mail it back to you.
Background
On November 11, 2006, Symphony Aircraft Industries, Inc. applied to
the FAA for a type design change to the SA160 airplane. The Symphony
Aircraft SA160 is currently approved under TC No. A46CE. 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 part 21, Sec. 21.101, Symphony
Aircraft Industries, Inc. must show that the SA160 aircraft design
change meets the following provisions, or the applicable regulations in
effect on the date of application for the change to the project: Cert
basis, 14 CFR part 23 effective February 1, 1965, including Amendments
23-1 through 23-53; 14 CFR part 36 effective November 18, 1969,
including Amendments 36-1 through 36-22; as applicable, and Sec.
23.1301 of Amendment 23-20; Sec. Sec. 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.
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. 21.101
(b)(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.
[[Page 39556]]
Novel or Unusual Design Features
Symphony Aircraft Industries, 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 EFIS, 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 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
------------------------------------------------------------------------
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 peak
rms, 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 the
SA160 Avidyne Entegra Avionics Suite project. Should Symphony Aircraft
Industries, Inc. 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.
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
21.101; and 14 CFR 11.38 and 11.19.
[[Page 39557]]
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 SA160 Avidyne Entegra Avionics Suite
Project airplane modified by Symphony Aircraft Industries, 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 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 July 6, 2007.
David R. Showers,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-14050 Filed 7-18-07; 8:45 am]
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