06-253. 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.

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 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 [phone].

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, § 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 § 23.1301 of Amendment 23-20; §§ 23.1309, 23.1311, and 23.1321 of Amendment 23-49; and § 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, Rev. 13, 9/18/97	A4EA, 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/B36TC/E33/A/C/F33/A/C/G33/H35/J35/K35/M35/N35/P35/S35/V35/V35A/V35B	3A15, Rev. 88, 1/15/00
Beechcraft Models 3N/3NM/3TM/C-45G/H/D18C/D18S/E18S/-9700/G18S/H18/JRB-6/RC-45J/TC-45G/TC-45H/TC-45J	A-765, Rev. 74, 4/15/96
Beechcraft Models 45, A45, D45	5A3, Rev. 25, 4/15/96
Beechcraft Models 50/B50/C50/D50/D50A/B/C/E/E-5990/E50/F50/G50/H50/J50	5A4, Rev. 60, 4/15/96
Beechcraft Models 56TC/58/58A/95/95-55/95-A55/A56TC/95-B55/95-B55A/95-B55B/95-C55/95-C55A/B95/B95A/D55/D55A/D95A/E55/E55A/E95	3A16, Rev. 80, 1/15/00
Beechcraft Models 58P/PA/TC/TCA	A23CE, Rev. 14, 4/15/96
Beechcraft Models 65/-80/-88/-90/-A80/-A80-8800/-A90/-A90-1/-A90-2/-A90-3/-A90-4/-B80/70/A65/-8200/B90/C90/A/E90/H90	3A20, Rev. 60, 9/10/01
Britten-Norman Models BN-2/A/2A-2/2A-20/2A-21/2A-26/2A-27/2A-3/2A-6/2A-8/2A-9/2B-20/2B-21/2B-26/2B-27/2T//2T-4R	A17EU, Rev. 15, 1/3/96
Beechcraft Models 200, 200C, 200CT, 200T, B200, B200C, 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)	A24CE, Rev. 89, 1/17/05
Britten-Norman Models BN2A MK. 111/-2/-3	A29EU, Rev. 3, 6/21/78
British Aerospace Models HP.137 Jetstream Mk.1, Jetstream Series 200, Jetstream Series 3101	A21EU, Rev. 16, 10/6/03
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/C/D/E/F/G/U206/A/B/C/D/E/F/G	A4CE, Rev. 40, 6/19/02
Cessna 207/A/T207/A	A16CE, Rev. 20, 10/15/94
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, 172G, 172H, 172I, 172K, 172L, 172M, 172N, 172P, 172Q, 172R, 172S	3A12, Rev. 69, 3/31/03
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/R182/T182/T/TR182	3A13, Rev. 59, 12/12/01
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/TU206A/B/C/D/E/F/G/U206/A/B/C/D/E/F/G	A4CE, Rev. 41, 3/31/03
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/J/K/L/M/N/R/P210N/R/T210F/G/H/J/K/L/M/N/R	3A21, Rev. 45, 8/15/96
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/E310H/E310J/T310P/Q/R	3A10, Rev. 61, 11/15/97
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/D/E/F/G/H/H-SP	A6CE, Rev. 38, 10/11/01
Cessna Models 401/A/B/402/A/B/C/411/A/414/A/421/A/B/C/425	A7CE, Rev. 44, 5/15/99
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/681/685/690/A/B/C/D/695/A/B/720	2A4, Rev. 46 04/03/2000
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, Dornier 228-101, Dornier 228-200, Dornier 228-201, Dornier 228-202, Dornier 228-212	A16EU, Rev. 8, 10/23/90
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, SA226-T(B), SA227-AT, SA227-TT	A5SW, Rev. 26, 8/24/04
Fairchild Models SA226-TC, SA227-AC (C-26A), SA227-PC, SA227-BC (C-26A)	A8SW, Rev. 22, 8/24/04
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/700/800/T-295	1A8, Rev. 33, 9/18/97
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-7-160, MX-7-180A, MX-7-180B, MX-7-180C, M-7-260C, M-7-420AC, MX-7-160C, MX-7-180AC	3A23, Rev. 29, 3/06/03
Maule Models Bee Dee M-4/M-4/-180C/S/T/-210/C/S/T/-220/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	3A23, Rev. 28, 4/6/00
Mitsubishi Models MU-2B/-10/-15/-20/-25/-26/-30/-35/-36	A2PC, Rev. 16, 6/30/75
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 II)/M.S. 760.A (Paris IA)	7A3, Rev. 3, 3/17/98
Partenavia/Vulcanair Models P68/B/C/C- TC/“OBSERVER”/AP68TP300“SPARTACUS”/P68TC “OBSERVER”/AP68TP“VIATOR”/P68“OBSERVER 2”	A31EU, Rev. 14, 5/30/00
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/-H1/-H2/B-H2/B1-H2/B2-H2/B2-H4/C-H2/C1-H2	7A15, Rev. 11, 8/9/99
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/AS-135/AS-150/S/S-105/S-125/S-135/S-150	1A2, Rev. 37, 9/4/96
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, PA-E23-250	1A10, Rev. 50, 9/10/03
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/235/236/R-180/RT-201T/S-160/S-180/R-200/R-201/R-201T//RT-201	2A13, Rev. 45, 12/12/01
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/-301T/PA-32RT-300/-300T/PA-32S-300	A3SO, Rev. 26, 7/23/97
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 § 21.16.

Special conditions, as appropriate, as defined in § 11.19, are issued in accordance with § 11.38 after public notice and become part of the type certification basis in accordance with § 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 § 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:

Frequency	Field strength (volts per meter)
	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 § 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

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.

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.