[Federal Register Volume 70, Number 76 (Thursday, April 21, 2005)]
[Rules and Regulations]
[Pages 20706-20708]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-7977]


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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