[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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