Special Conditions; Premier Avionics Design Ltd., EFIS on the Cessna 441; Protection of Systems for High Intensity Radiated Fields (HIRF), 56564-56566 [05-19289]

Download as PDF 56564 Federal Register / Vol. 70, No. 187 / Wednesday, September 28, 2005 / Rules and Regulations Administrative Procedure Act The Board did not follow the provisions of 5 U.S.C. 553(b) relating to notice and public participation in connection with the adoption of these amendments because the Board for good cause determined that delaying implementation of the new primary and secondary credit rates in order to allow notice and public comment would be unnecessary and contrary to the public interest in fostering price stability and sustainable economic growth. For these same reasons, the Board also has not provided 30 days prior notice of the effective date of the rule under section 553(d). List of Subjects in 12 CFR Part 201 Banks, Banking, Federal Reserve System, Reporting and recordkeeping. Federal Reserve Bank Rate Boston ............ New York ....... Philadelphia ... Cleveland ....... Richmond ....... Atlanta ............ Chicago .......... St. Louis ......... Minneapolis .... Kansas City ... Dallas ............. San Francisco 5.25 5.25 5.25 5.25 5.25 5.25 5.25 5.25 5.25 5.25 5.25 5.25 September September September September September September September September September September September September * * * * * 20, 20, 20, 22, 20, 22, 20, 21, 20, 20, 22, 20, 2005. 2005. 2005. 2005. 2005. 2005. 2005. 2005. 2005. 2005. 2005. 2005. By order of the Board of Governors of the Federal Reserve System, September 22, 2005. Jennifer J. Johnson, Secretary of the Board. [FR Doc. 05–19395 Filed 9–27–05; 8:45 am] BILLING CODE 6210–01–P Authority and Issuance For the reasons set forth in the preamble, the Board is amending 12 CFR chapter II as follows: DEPARTMENT OF TRANSPORTATION PART 201—EXTENSIONS OF CREDIT BY FEDERAL RESERVE BANKS (REGULATION A) 14 CFR Part 23 I Federal Aviation Administration 1. The authority citation for part 201 continues to read as follows: I Authority: 12 U.S.C. 248(i)–(j), 343 et seq., 347a, 347b, 347c, 348 et seq., 357, 374, 374a, and 461. 2. In § 201.51, paragraphs (a) and (b) are revised to read as follows: I (a) Primary credit. The interest rates for primary credit provided to depository institutions under § 201.4(a) are: Federal Reserve Bank Rate Boston ............ New York ....... Philadelphia ... Cleveland ....... Richmond ....... Atlanta ............ Chicago .......... St. Louis ......... Minneapolis .... Kansas City ... Dallas ............. San Francisco 4.75 4.75 4.75 4.75 4.75 4.75 4.75 4.75 4.75 4.75 4.75 4.75 Effective September September September September September September September September September September September September 20, 20, 20, 22, 20, 22, 20, 21, 20, 20, 22, 20, 2005. 2005. 2005. 2005. 2005. 2005. 2005. 2005. 2005. 2005. 2005. 2005. (b) Secondary credit. The interest rates for secondary credit provided to depository institutions under 201.4(b) are: 1 The primary, secondary, and seasonal credit rates described in this section apply to both advances and discounts made under the primary, secondary, and seasonal credit programs, respectively. VerDate Aug<31>2005 15:14 Sep 27, 2005 Jkt 205001 [Docket No. CE231, Special Condition 23– 171–SC] Special Conditions; Premier Avionics Design Ltd., EFIS on the Cessna 441; Protection of Systems for High Intensity Radiated Fields (HIRF) Federal Aviation Administration (FAA), DOT. ACTION: Final special conditions; request for comments. AGENCY: § 201.51 Interest rates applicable to credit extended by a Federal Reserve Bank.1 SUMMARY: These special conditions are issued to Premier Avionics Design Ltd., 12002 Warfield, Suite 250, San Antonio, TX 78216, for a Supplemental Type Certificate for the Cessna 441 Conquest. This airplane will have novel and unusual design features when compared to the state of technology envisaged in the applicable airworthiness standards. These novel and unusual design features include the installation of an electronic flight instrument system (EFIS) in the form of two digital altimeters. The digital altimeters will be Thommen Model AD32E, one on the pilot side and one on the copilot side, for which the applicable regulations do not contain adequate or appropriate airworthiness standards for the protection of these systems from the effects of high intensity radiated fields (HIRF). These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to the airworthiness standards applicable to these airplanes. PO 00000 Frm 00004 Fmt 4700 Sfmt 4700 The effective date of these special conditions is September 13, 2005. Comments must be received on or before October 28, 2005. ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation Administration, Regional Counsel, ACE–7, Attention: Rules Docket Clerk, Docket No. CE231, Room 506, 901 Locust, Kansas City, Missouri 64106. All comments must be marked: Docket No. CE231. 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: Wes Ryan, Aerospace Engineer, Standards Office (ACE–110), Small Airplane Directorate, Aircraft Certification Service, Federal Aviation Administration, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone (816) 32-4127. 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 design 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. DATES: Effective 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 notice 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 Docket No. CE231.’’ The postcard will be date stamped and returned to the commenter. E:\FR\FM\28SER1.SGM 28SER1 Federal Register / Vol. 70, No. 187 / Wednesday, September 28, 2005 / Rules and Regulations Background Premier Avionics made application to the FAA for a new Supplemental Type Certificate for the Cessna 441. The Cessna 441 is currently approved under TC No. A28CE. The proposed modification incorporates a novel or unusual design features, such as digital avionics consisting of digital air data computers that are vulnerable to HIRF external to the airplane. Type Certification Basis Under the provisions of 14 CFR part 21, § 21.101, Premier Avionics must show that the Cessna 441 aircraft meets the original certification basis for the airplane, as listed on Type Data Sheet A28CE, the additional certification requirements added for the Thommen AD32E systems, exemptions, if any; and the special conditions adopted by this rulemaking action. The rules that were applied at the amendment appropriate for the application date for this STC include 23.1301, 23.1309, 23.1311, 23.1321, and 23.1322. 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. 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 Premier Avionics plans to incorporate certain novel and unusual design features into the Cessna 441 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 VerDate Aug<31>2005 15:14 Sep 27, 2005 Jkt 205001 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 the 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 below: PO 00000 Frm 00005 Fmt 4700 Sfmt 4700 Frequency Field strength (volts per meter) Peak 10 kHz–100 kHz ........... 100 kHz–500 kHz ......... 500 kHz–2 MHz ............ 2 MHz–30 MHz ............. 30 MHz–70 MHz ........... 70 MHz–100 MHz ......... 100 MHz–200 MHz ....... 200 MHz–400 MHz ....... 400 MHz–700 MHz ....... 700 MHz–1 GHz ........... 1 GHz–2 GHz ............... 2 GHz–4 GHz ............... 4 GHz–6 GHz ............... 6 GHz–8 GHz ............... 8 GHz–12 GHz ............. 12 GHz–18 GHz ........... 18 GHz–40 GHz ........... 56565 50 50 50 100 50 50 100 100 700 700 2000 3000 3000 1000 3000 2000 600 Average 50 50 50 100 50 50 100 100 50 100 200 200 200 200 300 200 200 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. E:\FR\FM\28SER1.SGM 28SER1 56566 Federal Register / Vol. 70, No. 187 / Wednesday, September 28, 2005 / Rules and Regulations Applicability As discussed above, these special conditions are applicable to the Cessna 441. Should Premier Avionics apply at a later date for a supplemental type certificate to modify any other model on the same type certificate 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 § 21.101. Conclusion This action affects only certain novel or unusual design features on one model of airplane. 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 The authority citation for these special conditions is as follows: I 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 the Cessna 441 airplane modified by Premier Avionics Design Ltd. to add two Thommen AD32E Air Data Display Units. 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 I VerDate Aug<31>2005 15:14 Sep 27, 2005 Jkt 205001 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 September 13, 2005. James E. Jackson, Acting Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 05–19289 Filed 9–27–05; 8:45 am] BILLING CODE 4910–13–P ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [R06–OAR–2005–TX–0016; FRL–7975–9] Approval and Promulgation of Air Quality Implementation Plans; Texas; Permits by Rule Environmental Protection Agency (EPA). ACTION: Direct final rule. AGENCY: SUMMARY: EPA is taking direct final action to approve a State Implementation Plan (SIP) revision for the State of Texas. This action removes a provision from the Texas SIP which provided public notice for concrete batch plants which were constructed under a permit by rule (PBR). On September 1, 2000, Texas replaced the PBR for concrete batch plants with a standard permit for concrete batch plants. The standard permit for concrete batch plants also requires public notice for concrete batch plants subject to the standard permit. Texas maintained the public notice requirements of its PBR to assure that proper procedures were followed for concrete batch plants that were permitted under the PBR prior to the effective date of the standard permit. All authorization requests for concrete batch plants which were constructed under the PBR have now been resolved and the public notice and comment provisions under the PBR are no longer needed. DATES: This rule is effective on November 28, 2005 without further notice, unless EPA receives adverse comment by October 28, 2005. If EPA receives such comment, EPA will publish a timely withdrawal in the PO 00000 Frm 00006 Fmt 4700 Sfmt 4700 Federal Register informing the public that this rule will not take effect. ADDRESSES: Submit your comments, identified by Regional Material in DOCKET (RME) ID No. R06–OAR– 2005–TX–0016, by one of the following methods: • Federal rulemaking Portal: http:// www.regulations.gov. Follow the on-line instructions for submitting comments. • Agency Web site: http:// docket.epa.gov/rmepub/. Regional Material in DOCKET (RME), EPA’s electronic public docket and comment system, is EPA’s preferred method for receiving comments. Once in the system, select ‘‘quick search,’’ then key in the appropriate RME Docket identification number. Follow the online instructions for submitting comments. • U.S. EPA Region 6 ‘‘Contact Us’’ Web site: http://epa.gov/region6/ r6coment.htm. Please click on ‘‘6PD’’ (Multimedia) and select ‘‘Air’’ before submitting comments. • E-mail: Mr. David Neleigh at neleigh.david@epa.gov. Please also cc the person listed in the FOR FURTHER INFORMATION CONTACT section below. • Fax: Mr. David Neleigh, Chief, Air Permits Section (6PD–R), at fax number 214–665–7263. • Mail: Mr. David Neleigh, Chief, Air Permits Section (6PD–R), Environmental Protection Agency, 1445 Ross Avenue, Suite 1200, Dallas, Texas 75202–2733. • Hand or Courier Delivery: Mr. David Neleigh, Chief, Air Permits Section (6PD–R), Environmental Protection Agency, 1445 Ross Avenue, Suite 1200, Dallas, Texas 75202–2733. Such deliveries are accepted only between the hours of 8 a.m. and 4 p.m. weekdays except for legal holidays. Special arrangements should be made for deliveries of boxed information. Instructions: Direct your comments to Regional Material in DOCKET (RME) ID No. R06–OAR–2005–TX–0016. EPA’s policy is that all comments received will be included in the public file without change, and may be made available online at http:// docket.epa.gov/rmepub/, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information the disclosure of which is restricted by statute. Do not submit information through Regional Material in DOCKET (RME), Regulations.gov, or e-mail if you believe that it is CBI or otherwise protected from disclosure. The EPA RME Web site and the federal regulations.gov are ‘‘anonymous access’’ systems, which means EPA will not E:\FR\FM\28SER1.SGM 28SER1

Agencies

[Federal Register Volume 70, Number 187 (Wednesday, September 28, 2005)]
[Rules and Regulations]
[Pages 56564-56566]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-19289]


=======================================================================
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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE231, Special Condition 23-171-SC]


Special Conditions; Premier Avionics Design Ltd., EFIS on the 
Cessna 441; Protection of Systems for High Intensity Radiated Fields 
(HIRF)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

-----------------------------------------------------------------------

SUMMARY: These special conditions are issued to Premier Avionics Design 
Ltd., 12002 Warfield, Suite 250, San Antonio, TX 78216, for a 
Supplemental Type Certificate for the Cessna 441 Conquest. This 
airplane will have novel and unusual design features when compared to 
the state of technology envisaged in the applicable airworthiness 
standards. These novel and unusual design features include the 
installation of an electronic flight instrument system (EFIS) in the 
form of two digital altimeters. The digital altimeters will be Thommen 
Model AD32E, one on the pilot side and one on the copilot side, for 
which the applicable regulations do not contain adequate or appropriate 
airworthiness standards for the protection of these systems from the 
effects of high intensity radiated fields (HIRF). These special 
conditions contain the additional safety standards that the 
Administrator considers necessary to establish a level of safety 
equivalent to the airworthiness standards applicable to these 
airplanes.

DATES: The effective date of these special conditions is September 13, 
2005. Comments must be received on or before October 28, 2005.

ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation 
Administration, Regional Counsel, ACE-7, Attention: Rules Docket Clerk, 
Docket No. CE231, Room 506, 901 Locust, Kansas City, Missouri 64106. 
All comments must be marked: Docket No. CE231. 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: Wes Ryan, Aerospace Engineer, 
Standards Office (ACE-110), Small Airplane Directorate, Aircraft 
Certification Service, Federal Aviation Administration, 901 Locust, 
Room 301, Kansas City, Missouri 64106; telephone (816) 32-4127.

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 design 
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 notice 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 Docket No. CE231.'' The postcard will be date stamped and 
returned to the commenter.

[[Page 56565]]

Background

    Premier Avionics made application to the FAA for a new Supplemental 
Type Certificate for the Cessna 441. The Cessna 441 is currently 
approved under TC No. A28CE. The proposed modification incorporates a 
novel or unusual design features, such as digital avionics consisting 
of digital air data computers that are vulnerable to HIRF external to 
the airplane.

Type Certification Basis

    Under the provisions of 14 CFR part 21, Sec.  21.101, Premier 
Avionics must show that the Cessna 441 aircraft meets the original 
certification basis for the airplane, as listed on Type Data Sheet 
A28CE, the additional certification requirements added for the Thommen 
AD32E systems, exemptions, if any; and the special conditions adopted 
by this rulemaking action. The rules that were applied at the amendment 
appropriate for the application date for this STC include 23.1301, 
23.1309, 23.1311, 23.1321, and 23.1322.

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.
    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

    Premier Avionics plans to incorporate certain novel and unusual 
design features into the Cessna 441 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 the 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 below:

------------------------------------------------------------------------
                                                        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.

[[Page 56566]]

Applicability

    As discussed above, these special conditions are applicable to the 
Cessna 441. Should Premier Avionics apply at a later date for a 
supplemental type certificate to modify any other model on the same 
type certificate 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 one model of airplane. 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.

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 441 airplane modified by 
Premier Avionics Design Ltd. to add two Thommen AD32E Air Data Display 
Units.
    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 September 13, 2005.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-19289 Filed 9-27-05; 8:45 am]
BILLING CODE 4910-13-P