[Federal Register: April 21, 2005 (Volume 70, Number 76)]
[Rules and Regulations]
[Page 20706-20708]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21ap05-7]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE222; Special Conditions No. 23-162-SC]
Special Conditions: Garmin International Inc.; Cessna Model 182T/
T182T Airplane; Installation of Electronic Flight Instrument System and
the Protection of the System 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 for Garmin International
Inc., 1200 E. 151st St., Olathe, KS 66062, for a Supplemental Type
Certificate on the Cessna Model 182T/T182T airplanes. These airplanes,
as modified by Garmin, will have a novel or unusual design feature(s)
associated with the installation of a Garmin GFC-700 digital autopilot
system. These special conditions address the protection of these
systems from the effects of high intensity radiated field (HIRF)
environments. The applicable airworthiness regulations do not contain
adequate or appropriate safety standards for this design feature. 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.
DATES: The effective date of these special conditions is April 8, 2005.
Comments must be received on or before May 23, 2005.
ADDRESSES: Comments on these special conditions may be mailed in
duplicate to: Federal Aviation Administration, Regional Counsel, ACE-7,
Attention: Rules Docket CE222, 901 Locust, Room 506, Kansas City,
Missouri 64106; or delivered in duplicate to the Regional Counsel at
the above address. Comments must be marked: CE222. 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: Mr. Wes Ryan, Federal Aviation
Administration, Aircraft Certification Service, Small Airplane
Directorate, ACE-114, 901 Locust, Room 301, Kansas City, Missouri, 816-
329-4127, fax 816-329-4090.
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 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 special condition 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 CE222.'' The postcard will be date stamped and returned
to the commenter.
Background
On October 27, 2004, Garmin International Inc. applied for a
Supplemental Type Certificate for the Cessna Model 182T and Model T182T
to install a Garmin GFC-700 digital autopilot. The Cessna Model 182T
and T182T are single engine, high wing airplanes capable of carrying
four passengers. The proposed modification incorporates a novel or
unusual design feature, such as a digital electronic autopilot system
that may be vulnerable to HIRF external to the airplane.
Type Certification Basis
Under the provisions of 14 CFR part 21, Sec. 21.101, Garmin
International, Inc. must show that the Cessna 182T and T182T aircraft
meet the following original certification basis provisions or the
applicable regulations in effect on the date of application for the
change to the Cessna 182T and T182T:
[[Page 20707]]
For the 182 Series
Part 3 of the Civil Air Regulations dated November 1, 1949, as
amended by 3-1 through 3-12 and Paragraph 3.112, as amended October 1,
1959, for the Model 182E and on. In addition, effective S/N 18266591
through 18268586, 14 CFR, part 23, Sec. 23.1559, effective March 1,
1978; 14 CFR part 36, dated December 1, 1969, plus Amendments 36-1
through 36-6 for Model 182Q and on. In addition, effective S/N 18268435
through 18268486, 14 CFR, part 23, Sec. 23.1545(a), Amendment 23-23,
dated December 1, 1978; exemptions, if any, and the special conditions
adopted by this rulemaking action.
For the Model T182
Part 3 of the Civil Air Regulations dated November 1, 1949, as
amended by 3-1 through 3-12 and Paragraph 3.112 as amended October 1,
1959; and 14 CFR, part 23, Sec. Sec. 23.901, 23.909, 23.1041, 23.1043,
23.1143, and 23.1305, dated February 1, 1965, as amended February 14,
1975; 14 CFR, part 23, Sec. 23.1559, effective March 1, 1978; 14 CFR,
part 36, dated December 1, 1969; plus Amendments 36-1 through 36-10. In
addition, effective S/N 18268435 through 18268541, 14 CFR, part 23,
Sec. 23.1545(a); Amendment 23-23, dated December 1, 1978; exemptions,
if any, and the special conditions adopted by this rulemaking action.
For the GFC-700 Autopilot
The following certification requirements were applied to the GFC-
700 digital autopilot, so they also become part of the certification
basis of the Cessna 182T and T182T when modified with the GFC-700
autopilot system: Sec. 23.1301, Amendment 20; Sec. 23.1309, Amendment
49; Sec. 23.1311, Amendment 49; Sec. 23.1321, Amendment 49, Sec.
23.1322, Amendment 43; Sec. 23.1327, Amendment 20; Sec. 23.1329,
Amendment 49; Sec. 23.1335, Amendment 20; Sec. 23.1351, Amendment 49;
Amendment 20; Sec. 23.1353, Amendment 49; Amendment 20; Sec. 23.1357,
Amendment 43; Amendment 20; Sec. 23.1359, Amendment 49; Amendment 20;
Sec. 23.1365, Amendment 49; and Sec. 23.1431, Amendment 49;
exemptions, if any, and the special conditions adopted by this
rulemaking action.
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 23) do not contain adequate or
appropriate safety standards for the Cessna Model 182T and T182T
because of a novel or unusual design feature, 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, and become part of the type
certification basis in accordance with Sec. 21.101(b)(2).
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
Garmin International, Inc. plans to incorporate certain novel and
unusual design features into the Cessna 182T and T182T airplanes for
which the airworthiness standards do not contain adequate or
appropriate safety standards for protection from the effects of HIRF.
These features include a digital autopilot that may be susceptible to
the HIRF environment, 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 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 as follows:
------------------------------------------------------------------------
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,
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
[[Page 20708]]
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
Cessna 182T and T182T airplanes with the Garmin GFC-700 digital
autopilot. Should Garmin International Inc. apply later for a
Supplemental Type Certificate on another model on the same type
certification data sheet 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 the Cessna 182T and T182T airplanes. 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.
PART 23--AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND
COMMUTER CATEGORY AIRPLANES
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 Cessna 182T and T182T airplanes to
include a Garmin GFC-700 Autopilot system.
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 April 8, 2005.
Nancy C. Lane,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-7977 Filed 4-20-05; 8:45 am]
BILLING CODE 4910-13-P