Federal Register, Volume 71 Issue 8 (Thursday, January 12, 2006)

[Federal Register Volume 71, Number 8 (Thursday, January 12, 2006)]
[Rules and Regulations]
[Pages 1926-1930]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-253]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE187; Special Conditions No. 23-127A-SC]

Special Conditions: Chelton Flight Systems, Inc.; Various
Airplane Models; Protection of Systems for High Intensity Radiated
Fields (HIRF)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions: amendment.

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SUMMARY: The FAA published a document in the Federal Register on August
30, 2002 (Volume 67, Number 169) regarding Special Condition 23-127-SC
for Chelton Flight Systems, Various Airplane Models; Protection of
Systems for High Intensity Radiated Fields (HIRF). This amendment is
being published to add several airplane models to the existing special
condition to cover current and future amendments to the Approved Model
List (AML) STC. These special conditions address HIRF certification
requirements for digital systems not addressed by the current
regulations. See the attached AML for the airplanes that are added by
this amendment.
These airplanes, as modified by Chelton Flight Systems, will have a
novel or unusual design feature(s) associated with the installation of
an electronic flight instrument 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 amended special conditions is
December 22, 2005. Comments must be received on or before February 13,
2006.

ADDRESSES: Comments on these amended special conditions may be mailed
in duplicate to: Federal Aviation Administration, Regional Counsel,
ACE-7, Attention: Rules Docket CE187, 901 Locust, Room 506, Kansas
City, Missouri 64106; or delivered in duplicate to the Regional Counsel
at the above address. Comments must be marked: CE187. Comments may be
inspected in the Rules Docket

[[Page 1927]]

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-111, 901 Locust, Room 301, Kansas City, Missouri
64106, 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
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 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 CE187.'' The postcard will be date stamped and returned
to the commenter.

Background

On April 25, 2002, Chelton Flight Systems, Incorporated, 1109 Main
Street, Suite 560, Boise, ID 83702 made application to the FAA for a
new Supplemental Type Certificate for the airplane models listed in the
``Type Certification Basis'' Section of this Special Condition. The
proposed modification incorporates a new and novel feature, such as an
electronic flight instrument 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, Chelton
Flight Systems, Inc., must show that affected airplane models, as
changed, continue to meet the applicable provisions, of the regulations
incorporated by reference in Type Certificate Numbers listed below or
the applicable regulations in effect on the date of application for the
change. The regulations incorporated by reference in the type
certificate are commonly referred to as the original ``type
certification basis'' and can be found in the Type Certificate Numbers
listed below. In addition, the type certification basis of airplane
models that embody this modification will include 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. The following
models are covered by this special condition:

----------------------------------------------------------------------------------------------------------------
Models Type certificate number
----------------------------------------------------------------------------------------------------------------
Aero Planes, LLC: Models G-21C, G-21D, G-21E, G-21G 4A24, Rev. 7, 8/22/05
4A24, Rev. 7, 8/22/05.
Aerostar Models 360/400............................... A11WE, Rev. 4, 10/22/92
Aerostar Models PA-60-600/-601/-601P/-602P/-700P...... A17WE, Rev. 22
Alliance Aircraft Helio 550, 550A (USAF AU-24A) A4EA, A4EA, Rev. 13, 9/18/97
Rev. 13, 9/18/97.
American Champion Models 8GCBC/8KCAB.................. A21CE, Rev. 11, 8/25/97
Aviat A-1/-1A/-1B..................................... A22NM, Rev. 12, 6/15/00
Beechcraft 60/A60/B60................................. A12CE, Rev. 23, 4/15/96
Beechcraft Model 2000................................. A38CE, Rev. 10, 8/23/01
Beechcraft Model 3000................................. A00009WI, Rev. 8, 11/29/01
Beechcraft Model 76................................... A29CE, Rev. 5, 4/15/96
Beechcraft Model F90.................................. A31CE, Rev. 7, 4/15/96
Beechcraft Models 100/99/A/A100/A/C/A99/A/100B9/C99... A14CE, Rev. 35, 5/18/00
Beechcraft Models 18D/A18A/D/S18D/SA18A/D............. A-684, Rev. 2, 4/15/96
Beechcraft Models 35/R/A35/B35/C35/D35/E35/F35/G35.... A-777, Rev. 57, 4/15/96
Beechcraft Models 35-33/A33/B33/C33/C33A/36/A36/A36TC/ 3A15, Rev. 88, 1/15/00
B36TC/E33/A/C/F33/A/C/G33/H35/J35/K35/M35/N35/P35/S35/
V35/V35A/V35B.
Beechcraft Models 3N/3NM/3TM/C-45G/H/D18C/D18S/E18S/- A-765, Rev. 74, 4/15/96
9700/G18S/H18/JRB-6/RC-45J/TC-45G/TC-45H/TC-45J.
Beechcraft Models 45, A45, D45........................ 5A3, Rev. 25, 4/15/96
Beechcraft Models 50/B50/C50/D50/D50A/B/C/E/E-5990/E50/ 5A4, Rev. 60, 4/15/96
F50/G50/H50/J50.
Beechcraft Models 56TC/58/58A/95/95-55/95-A55/A56TC/95- 3A16, Rev. 80, 1/15/00
B55/95-B55A/95-B55B/95-C55/95-C55A/B95/B95A/D55/D55A/
D95A/E55/E55A/E95.
Beechcraft Models 58P/PA/TC/TCA....................... A23CE, Rev. 14, 4/15/96
Beechcraft Models 65/-80/-88/-90/-A80/-A80-8800/-A90/- 3A20, Rev. 60, 9/10/01
A90-1/-A90-2/-A90-3/-A90-4/-B80/70/A65/-8200/B90/C90/
A/E90/H90.
Britten-Norman Models BN-2/A/2A-2/2A-20/2A-21/2A-26/2A- A17EU, Rev. 15, 1/3/96
27/2A-3/2A-6/2A-8/2A-9/2B-20/2B-21/2B-26/2B-27/2T//2T-
4R.
Beechcraft Models 200, 200C, 200CT, 200T, B200, B200C, A24CE, Rev. 89, 1/17/05
B200CT, B200T, 300, 300LW, B300, B300C, 1900, 1900C,
1900D, A100-1 (U-21J), A200 (C-12A), A200 (C-12C),
A200C (UC-12B), A200CT (C-12D), A200CT (FWC-12D),
A200CT (C-12F), A200CT (RC-12D), A200CT (RC-12G),
A200CT (RC-12H), A200CT (RC-12K), A200CT (RC-12P),
A200CT (RC-12Q), B200C (C-12F), B200C (UC-12M), B200C
(C-12R), B200C (UC-12F), 1900C (UC-12J).
Britten-Norman Models BN2A MK. 111/-2/-3.............. A29EU, Rev. 3, 6/21/78
British Aerospace Models HP.137 Jetstream Mk.1, A21EU, Rev. 16, 10/6/03
Jetstream Series 200, Jetstream Series 3101.
British Aerospace Model Jetstream 3201................ A56EU, Rev. 5, 10/6/03
Cessna 206/H/P206/A/B/C/D/E/H/TP206A/B/C/D/E/TU206A/B/ A4CE, Rev. 40, 6/19/02
C/D/E/F/G/U206/A/B/C/D/E/F/G.
Cessna 207/A/T207/A................................... A16CE, Rev. 20, 10/15/94

[[Page 1928]]

Cessna Model 177RG.................................... A20CE, Rev. 18, 10/15/94
Cessna Model 336...................................... A2CE, Rev. 6, 6/15/99
Cessna Model 441...................................... A28CE, Rev. 11, 8/15/99
Cessna Model T303..................................... A34CE, Rev. 5, 10/15/94
Cessna Models 170/A/B................................. A-799, Rev. 51, 7/15/98
Cessna Models 172, 172A, 172B, 172C, 172D, 172E, 172F, 3A12, Rev. 69, 3/31/03
172G, 172H, 172I, 172K, 172L, 172M, 172N, 172P, 172Q,
172R, 172S.
Cessna Models 172RG/175/A/B/C/P172D/R172E/F/G/H/J/K... 3A17, Rev. 45, 3/31/03
Cessna Models 177/A/B................................. A13CE, Rev. 23, 10/15/94
Cessna Model 177RG.................................... A19SO, Rev. 9, 2/5/03
Cessna Models 180A/B/C/D/E/F/G/H/J/K.................. 5A6, Rev. 64, 10/11/01
Cessna Models 182/A/B/C/D/E/F/G/H/J/K/L/M/N/P/Q/R/S/T/ 3A13, Rev. 59, 12/12/01
R182/T182/T/TR182.
Cessna Models 185/A/B/C/D/E/A185E/F................... 3A24, Rev. 36, 11/15/99
Cessna 190, (LC-126A, B, C) 195, 195A, 195B........... A-790, Rev. 36, 3/15/03
Cessna Models 206/H/P206/A/B/C/D/E/H/TP206A/B/C/D/E/ A4CE, Rev. 41, 3/31/03
TU206A/B/C/D/E/F/G/U206/A/B/C/D/E/F/G.
Cessna Models 207/207A/T207/T207A..................... A16CE, Rev. 21, 3/31/03
Cessna Models 208/A/B................................. A37CE, Rev. 12, 6/15/99
Cessna Models 210/-5 (205)/-5A (205A)/A/B/C/D/E/F/G/H/ 3A21, Rev. 45, 8/15/96
J/K/L/M/N/R/P210N/R/T210F/G/H/J/K/L/M/N/R.
Cessna Model T303..................................... A34CE, Rev. 6, 3/31/03
Cessna Models 310/A/B/C/D/E/F/G/H/I/J/J-1/K/L/N/P/Q/R/ 3A10, Rev. 61, 11/15/97
E310H/E310J/T310P/Q/R.
Cessna Models 320/-1/A/B/C/D/E/F/335/340/A............ 3A25, Rev. 25, 8/15/94
Cessna Model 336...................................... A2CE, Rev. 7, 3/31/03
Cessna Models 337/A/B/C/D/E/F/G/H/M337B/P337H/T337B/C/ A6CE, Rev. 38, 10/11/01
D/E/F/G/H/H-SP.
Cessna Models 401/A/B/402/A/B/C/411/A/414/A/421/A/B/C/ A7CE, Rev. 44, 5/15/99
425.
Cessna Models 404/406................................. A25CE, Rev. 11, 6/15/95
Cessna Model 441...................................... A28CE, Rev. 12, 9/22/03
Cessna Models 501/551................................. A27CE, Rev. 15, 2/25/02
Cessna Models 525/A................................... A1WI, Rev. 11, 7/9/01
Cirrus Models SR20/22................................. A00009CH, Rev. 3, 9/28/01
Commander Model 700................................... A12SW, Rev. 10, 1/1/90
Commander Models 112/B/TC/TCA/114/A/B/TC.............. A12SO, Rev. 21, 8/4/95
Commander Models 500/-A/-B/-S/-U/520/560/A/-E......... 6A1, Rev. 45, 1/1/90
Commander Models 560-F/680/E/F/FL/FL(P)/F(P)/T/V/W/681/ 2A4, Rev. 46 04/03/2000
685/690/A/B/C/D/695/A/B/720.
de Havilland Model DHC-3.............................. A-815, Rev. 4, 6/26/98
de Havilland Models DHC-2 Mk.I/II/III................. A-806, Rev. 21, 1/21/94
de Havilland Models DHC-6-1/-100/-200/-300............ A9EA, Rev. 11, 6/20/00
Diamond Model DA-40................................... A47CE, Rev. 2, 4/8/02
Dornier Models Do 28 D, Do 28 D-1, Dornier 228-100, A16EU, Rev. 8, 10/23/90
Dornier 228-101, Dornier 228-200, Dornier 228-201,
Dornier 228-202, Dornier 228-212.
EMBRAER Models EMB-110P1, EMB-110P2................... A21SO, Rev. 6, 10/16/96
Extra Models EA-200/300/L/S........................... A67EU, Rev. 5, 06/03/99
Extra Model EA-400.................................... A43CE, Rev. 5, 3/5/02
Fairchild Models SA26-T, SA26-AT, SA226-T, SA226-AT, A5SW, Rev. 26, 8/24/04
SA226-T(B), SA227-AT, SA227-TT.
Fairchild Models SA226-TC, SA227-AC (C-26A), SA227-PC, A8SW, Rev. 22, 8/24/04
SA227-BC (C-26A).
Fairchild Models SA227-CC, SA227-DC (C-26B)........... A18SW, Rev. 4, 8/24/04
Found Aircraft Models FBA-2C, FBA-2C1................. A7EA, Rev. 2, 4/9/01
Found Brothers Model FBA Centennial ``100''........... A13EA, Rev. 0, 1/1/70
Grob Models G115EG/G115/A/B/C/C2/D/D2................. A57EU, Rev. 10, 2/6/01
Harbin Aircraft Manufacturing (HAMC): Model Y 12 IV... A00006WI, Rev. 3, 7/16/96
Helio Courier Models 15A/20........................... 3A3, Rev. 7, 3/1/91
Helio Courier Models H-250/295/391/391B/395/395A/700/ 1A8, Rev. 33, 9/18/97
800/T-295.
Israel Aircraft Models ARAVA 101, ARAVA 101B.......... A32EU, Rev. 3, 7/26/88
KWAD (Mitchell) Super-V............................... A5IN, Rev. 1, 10/13/78
Lancair Model LC40-550FG.............................. A00003SE, Rev.8, 2/26/02
Learjet Model 23...................................... A5CE, Rev. 10, 7/15/90
LET Model L-420....................................... A42CE, Rev. 3, 1/20/05
Maule Models MX-7-235, MX-7-180, MX-7-420, M-8-235, MX- 3A23, Rev. 29, 3/06/03
7-160, MX-7-180A, MX-7-180B, MX-7-180C, M-7-260C, M-7-
420AC, MX-7-160C, MX-7-180AC.
Maule Models Bee Dee M-4/M-4/-180C/S/T/-210/C/S/T/-220/ 3A23, Rev. 28, 4/6/00
C/S/T/M-4C/S/T/M-5-180C/-200/-210C/-210TC/-220C/-235C/
M-6-180/6-235/M-7-235/A/B/C/-260MT-7-235/-260/-160/-
160C/-180/A/AC/B/C/-235/-420 MXT-7-160/-180/A/-420/C/-
420AC/M-8-235.
Mitsubishi Models MU-2B/-10/-15/-20/-25/-26/-30/-35/- A2PC, Rev. 16, 6/30/75
36.
Mitsubishi Models MU-2B-25/-26/A/-35/-36/A/-40/-60.... A10SW, Rev. 13, 4/2/98
Mooney Models M20/A/B/C/D/E/F/G/J/K/L/M/R/S........... 2A3, Rev. 46, 8/10/99
Mooney Model M22...................................... A6SW, Rev. 6, 12/1/73
ParisJet Models M.S. 760 (Paris I)/M.S. 760B (Paris 7A3, Rev. 3, 3/17/98
II)/M.S. 760.A (Paris IA).
Partenavia/Vulcanair Models P68/B/C/C- TC/``OBSERVER''/ A31EU, Rev. 14, 5/30/00
AP68TP300``SPARTACUS''/P68TC ``OBSERVER''/
AP68TP``VIATOR''/P68``OBSERVER 2''.
Piaggio Model P-180................................... A59EU, Rev. 9, 10/25/00
Piaggio Models P.166, P.166B, P.166C, P.166DL3........ 7A4, Rev. 7, 10/31/78
Pilatus Model PC-7.................................... A50EU, Rev. 2, 7/1/96
Pilatus Models PC-12/-12/45........................... A78EU, Rev. 9, 3/30/01
Pilatus Models PC-6/-H1/-H2/PC-6/350/-H1/-H2 PC-6/A/- 7A15, Rev. 11, 8/9/99
H1/-H2/B-H2/B1-H2/B2-H2/B2-H4/C-H2/C1-H2.

[[Page 1929]]

Piper Models PA-12/S.................................. A-780, Rev. 13, 3/30/01
FS 2002/Piper PA-14................................... A-797, Rev. 11, 3/30/01
Piper Models PA-18/105/125/135/A/A-135/A-150/AS/AS-125/ 1A2, Rev. 37, 9/4/96
AS-135/AS-150/S/S-105/S-125/S-135/S-150.
Piper Models PA-18 ``150'', PA-19 (Army L-18C), PA-19S 1A2, Rev. 37, 9/4/96
Piper Models PA-23, PA-23-160, PA-23-235, PA-23-250, 1A10, Rev. 50, 9/10/03
PA-E23-250.
Piper Models PA-24/250/260/400........................ 1A15, Rev. 33, 10/1/97
Piper Models PA-28-140/150/151/160/161/180/181/201T/ 2A13, Rev. 45, 12/12/01
235/236/R-180/RT-201T/S-160/S-180/R-200/R-201/R-201T//
RT-201.
Piper Models PA-28R-200, PA-28R-201, PA-28R-201T...... 2A13, Rev. 45, 12/12/01
Piper Models PA-30/-39/-40............................ A1EA, Rev. 15, 10/1/97
Piper Models PA-31/-300/-325/-350..................... A20SO, Rev.9, 3/19/01
Piper Models PA-31P/-350/PA-31T/1/2/3................. A8EA, Rev. 21, 4/8/98
Piper Models PA-32-301FT, PA-32-301XTC................ A3SO, Rev. 27, 11/25/03
Piper Models PA-32-260/-300/-301/T/PA-32R-300/ -301/- A3SO, Rev. 26, 7/23/97
301T/PA-32RT-300/-300T/PA-32S-300.
Piper Models PA-34-200/-200T/-220T.................... A7SO, Rev. 14, 6/1/01
Piper Models PA-42/-42-1000/-42-720 A23SO, Rev. 14, 11/
16/01.
Piper Models PA-44-180/T.............................. A19SO, Rev. 8, 11/14/01
Piper Models PA-46-310P/-350P/-500TP.................. A25SO, Rev. 10, 1/2/02
Polskie Zaklady Lotnicze Model PZL M28 05............. A56CE, Original, 3/19/04
Revo Models Colonial C-1/-2, Lake LA-4/A/P/-200/250... 1A13, Rev. 25, 11/8/99
Ruschmeyer Model R90-230RG............................ A77EU, Rev. 0, 6/24/94
SIAI Marchetti: Models SF600, SF600A.................. A61EU, Rev. 2, 6/05/96
Shorts Models SC-7 Series 2/SC-7 Series 3............. A15EU, Rev. 9, 8/1/90
Slingsby Models T67M260/-T3A.......................... A73EU, Rev. 4, 7/27/00
Socata Model TBM-700.................................. A60EU, Rev. 8, 11/6/01
Socata Models TB 10/20/200/21/9....................... A51EU, Rev. 14, 4/6/01
Thurston/Teal Models TSC-1A, TSC-1A1, TSC-1A2......... A15EA, Rev. 11, 2/10/93
----------------------------------------------------------------------------------------------------------------

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) of Amendment 21-69.
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

Chelton Flight Systems, 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 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:

[[Page 1930]]

------------------------------------------------------------------------
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 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 one
modification to the airplane models listed under the heading ``Type
Certification Basis.'' Should Chelton Flight Systems, Inc., apply to
extend this modification to include additional airplane models, the
special conditions would extend to these models as well under the
provisions of Sec. 21.101.

Conclusion

This action affects only certain novel or unusual design features
of one modification to several models of 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 some airplane
models, 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. 21.101; and 14 CFR 11.38 and 11.19.

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 airplane models listed under the
``Type Certification Basis'' heading modified by Chelton Flight
Systems, 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 December 22, 2005.
Kim Smith,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 06-253 Filed 1-11-06; 8:45 am]
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