Special Conditions; West Star Aviation, EFIS on the Cessna 441; Protection of Systems for High Intensity Radiated Fields (HIRF), 32711-32713 [05-10907]

Download as PDF Federal Register / Vol. 70, No. 107 / Monday, June 6, 2005 / Rules and Regulations the deposit, including interest; and advise the applicant of the total amount of deposit due. (2) The agency shall establish a deposit account showing the total amount due and a payment schedule (unless deposit is made in one lump sum) to record the date and amount of each payment. (3) If an eligible individual cannot make payment in one lump sum, the agency shall accept installment payments (by allotments or otherwise). The agency, however, is not required to accept individual checks in amounts less than $50. (4) Payments received by the agency shall be remitted to OPM immediately for deposit to the Civil Service Retirement and Disability Fund. (5) Once a deposit has been paid in full or otherwise closed out, the agency shall submit the documentation pertaining to the deposit to OPM in accordance with instructions issued by OPM. (h) Effect of deposit. An individual completing a deposit under this section whose entitlement to an annuity is based on a separation from service on or after February 10, 2004, will receive air traffic controller retirement credit for such service, for annuity entitlement and computation purposes, when OPM receives certification that the deposit has been paid in full, and the deposit payment is remitted to the Civil Service Retirement and Disability Fund. [FR Doc. 05–11134 Filed 6–3–05; 8:45 am] BILLING CODE 6325–39–P DEPARTMENT OF AGRICULTURE Rural Utilities Service 7 CFR Part 1738 RIN 0572–AB81 Rural Broadband Access Loans and Loan Guarantees Rural Utilities Service, USDA. Notice of confirmation of direct final rule. AGENCY: ACTION: The Rural Utilities Service (RUS), an agency delivering the United States Department of Agriculture’s Rural Development Utilities Programs, gives notice that no adverse comments were received regarding the direct final rule amending its regulations to revise the definition for ‘‘eligible rural community’’ as it relates to the rural access broadband loans and loan guarantees program, and confirms the effective date of the direct final rule. SUMMARY: VerDate jul<14>2003 18:06 Jun 03, 2005 Jkt 205001 The direct final rule published in the Federal Register on April 4, 2005, (70 FR 16930) was effective on May 19, 2005. DATES: FOR FURTHER INFORMATION CONTACT: Jonathan Claffey, Acting Assistant Administrator, Telecommunications Program, Rural Utilities Service, U.S. Department of Agriculture, 1400 Independence Avenue, SW., STOP 1590, Room 4056, Washington, DC 20250–1590. Telephone number (202) 720–9554, Facsimile (202) 720–0810. SUPPLEMENTARY INFORMATION: Background The Rural Utilities Service (RUS) published in the Federal Register on January 30, 2003, at 68 FR 4684, a final rule amending its regulations in order to establish the Rural Broadband Access Loan and Loan Guarantee Program as authorized by the Farm Security and Rural Investment Act of 2002 (Pub. L. 101–171) (2002 Act). Section 6103 of the Farm Security and Rural Investment Act of 2002 amended the Rural Electrification Act of 1936, as amended (RE Act), to add Title VI, Rural Broadband Access, to provide loans and loan guarantees to fund the cost of construction, improvement, or acquisition of facilities and equipment for the provision of broadband service in eligible rural communities. The direct final rule amended § 1738.2, Definitions, to conform the rule to substantive changes in authority. The definition for ‘‘eligible rural community’’ in section 601(b)(2) of the Rural Electrification Act of 1936 (7 U.S.C. 950bb(b)(2)) was amended on January 23, 2004, by section 772 of Pub. L. 108–199, of the Consolidated Appropriations Act, 2004 to eliminate the requirement that a community exist outside a standard metropolitan statistical area. The rule incorporated language of the revised statute and explained RUS’’ interpretation of the language. Confirmation of Effective Date This is to confirm the effective date of May 19, 2005, for the direct final rule, 7 CFR 1738, Rural Broadband Access Loans and Loan Guarantees, published in the Federal Register on April 4, 2005. Dated: May 26, 2005. Curtis M. Anderson, Acting Administrator, Rural Utilities Service. [FR Doc. 05–11137 Filed 6–3–05; 8:45 am] BILLING CODE 3410–15–P PO 00000 Frm 00003 Fmt 4700 Sfmt 4700 32711 DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 23 [Docket No. CE224, Special Condition 23– 164–SC] Special Conditions; West Star Aviation, 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: SUMMARY: These special conditions are issued to West Star Aviation, 796 Heritage Way, Grand Junction, CO 81506, 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 Honeywell/Ametek AM–250 models, 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 May 18, 2005. Comments must be received on or before July 6, 2005. ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation Administration, Regional Counsel, ACE–7, Attention: Rules Docket Clerk, Docket No. CE224, Room 506, 901 Locust, Kansas City, Missouri 64106. All comments must be marked: Docket No. CE224. 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) 329–4127. E:\FR\FM\06JNR1.SGM 06JNR1 32712 Federal Register / Vol. 70, No. 107 / Monday, June 6, 2005 / Rules and Regulations 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. SUPPLEMENTARY INFORMATION: 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. CE224.’’ The postcard will be date stamped and returned to the commenter. Background West Star Aviation 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, West Star Aviation 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 Honeywell/ Ametek AM–250 system, exemptions, if any; and the special conditions adopted by this rulemaking action. The rules that VerDate jul<14>2003 18:06 Jun 03, 2005 Jkt 205001 were applied at the amendment appropriate for the application data for this STC are 23.1301 at Amendment 23– 20, 23.1309 at Amendment 23–49, 23.1311 at Amendment 49, 23.1321 at Amendment 49, 23.1322 at Amendment 43, 23.1325 at Amendment 50, and 23.1543 at Amendment 50. 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 West Star Aviation 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 PO 00000 Frm 00004 Fmt 4700 Sfmt 4700 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: 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 GHz0 ..... E:\FR\FM\06JNR1.SGM 06JNR1 50 50 50 100 50 50 100 100 700 700 2000 3000 3000 1000 3000 2000 Average 50 50 50 100 50 50 100 100 50 100 200 200 200 200 300 200 Federal Register / Vol. 70, No. 107 / Monday, June 6, 2005 / Rules and Regulations Field strength* (volts per meter) Conclusion This action affects only certain novel or unusual design features on one model of airplane. It is not a rule of general 18 GHz–40GHz ........ 600 200 applicability and affects only the applicant who applied to the FAA for * The field strengths are expressed in terms approval of these features on the of peak root-mean-square (rms) values. airplane. The substance of these special or, conditions has been subjected to the (2) The applicant may demonstrate by notice and comment period in several a system test and analysis that the prior instances and has been derived electrical and electronic systems that perform critical functions can withstand without substantive change from those previously issued. It is unlikely that a minimum threat of 100 volts per prior public comment would result in a meter, electrical field strength, from 10 significant change from the substance kHz to 18 GHz. When using this test to contained herein. For this reason, and show compliance with the HIRF because a delay would significantly requirements, no credit is given for affect the certification of the airplane, signal attenuation due to installation. which is imminent, the FAA has A preliminary hazard analysis must determined that prior public notice and be performed by the applicant for comment are unnecessary and approval by the FAA to identify either impracticable, and good cause exists for electrical or electronic systems that adopting these special conditions upon perform critical functions. The term issuance. The FAA is requesting ‘‘critical’’ means those functions, whose comments to allow interested persons to failure would contribute to, or cause, a submit views that may not have been failure condition that would prevent the submitted in response to the prior continued safe flight and landing of the opportunities for comment described airplane. The systems identified by the above. hazard analysis that perform critical List of Subjects in 14 CFR Part 23 functions are candidates for the application of HIRF requirements. A Aircraft, Aviation safety, Signs and system may perform both critical and symbols. non-critical functions. Primary Citation electronic flight display systems, and The authority citation for these their associated components, perform special conditions is as follows: critical functions such as attitude, altitude, and airspeed indication. The Authority: 49 U.S.C. 106(g), 40113 and HIRF requirements apply only to critical 44701; 14 CFR 21.16 and 21.101; and 14 CFR 11.38 and 11.19. functions. Compliance with HIRF requirements The Special Conditions may be demonstrated by tests, analysis, Accordingly, pursuant to the models, similarity with existing authority delegated to me by the systems, or any combination of these. Administrator, the following special Service experience alone is not conditions are issued as part of the type acceptable since normal flight certification basis for the Cessna 441 operations may not include an exposure airplane modified by West Star Aviation to the HIRF environment. Reliance on a to add two Honeywell/Ametek AM–250 system with similar design features for digital air data computers. redundancy as a means of protection 1. Protection of Electrical and against the effects of external HIRF is Electronic Systems from High Intensity generally insufficient since all elements Radiated Fields (HIRF). Each system of a redundant system are likely to be that performs critical functions must be exposed to the fields concurrently. designed and installed to ensure that the Frequency Peak Average Applicability As discussed above, these special conditions are applicable to the Cessna 441. Should West Star Aviation apply at a later date for a supplemental type certificate to modify any other model on the same type certificate 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. VerDate jul<14>2003 18:06 Jun 03, 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 PO 00000 Frm 00005 Fmt 4700 Sfmt 4700 32713 continued safe flight and landing of the airplane. Issued in Kansas City, Missouri on May 18, 2005. John R. Colomy, Acting Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 05–10907 Filed 6–3–05; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF AGRICULTURE Forest Service 36 CFR Part 228 RIN 0596–AC17 Clarification as to When a Notice of Intent To Operate and/or Plan of Operation Is Needed for Locatable Mineral Operations on National Forest System Lands Forest Service, USDA. Final rule. AGENCY: ACTION: SUMMARY: This final rule amends the regulations governing the use of National Forest System lands in connection with operations authorized by the United States mining laws. The final rule clarifies the regulations at 36 CFR 228.4(a) concerning the requirements for mining operators to submit a ‘‘notice of intent’’ to operate and requirements to submit and obtain an approved ‘‘plan of operations.’’ Clarification of the requirements in § 228.4(a) are necessary to minimize adverse environmental impacts to National Forest System lands and resources. DATES: The final rule is effective July 6, 2005. ADDRESSES: The documents used in developing this final rule are available for inspection and copying at the office of the Director, Minerals and Geology Management, Forest Service, USDA, 1601 N. Kent Street, 5th Floor, Arlington, VA 22209, during regular business hours (8:30 a.m. to 4:30 p.m.), Monday through Friday, except holidays. Those wishing to copy or inspect these documents are asked to call ahead (703) 605–4818 to facilitate access to the building. FOR FURTHER INFORMATION CONTACT: Mike Doran, Minerals and Geology Management Staff, (703) 605–4818. SUPPLEMENTARY INFORMATION: Background and Need for Final Rule For purposes of this final rule, all references to 36 CFR part 228, Subpart A, without qualifying terms ‘‘interim rule’’ or ‘‘final rule,’’ refer to language E:\FR\FM\06JNR1.SGM 06JNR1

Agencies

[Federal Register Volume 70, Number 107 (Monday, June 6, 2005)]
[Rules and Regulations]
[Pages 32711-32713]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-10907]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE224, Special Condition 23-164-SC]


Special Conditions; West Star Aviation, 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 West Star Aviation, 796 
Heritage Way, Grand Junction, CO 81506, 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 Honeywell/Ametek AM-250 models, 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 May 18, 2005. 
Comments must be received on or before July 6, 2005.

ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation 
Administration, Regional Counsel, ACE-7, Attention: Rules Docket Clerk, 
Docket No. CE224, Room 506, 901 Locust, Kansas City, Missouri 64106. 
All comments must be marked: Docket No. CE224. 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) 329-4127.

[[Page 32712]]


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. CE224.'' The postcard will be date stamped and 
returned to the commenter.

Background

    West Star Aviation 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, West Star 
Aviation 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 
Honeywell/Ametek AM-250 system, exemptions, if any; and the special 
conditions adopted by this rulemaking action. The rules that were 
applied at the amendment appropriate for the application data for this 
STC are 23.1301 at Amendment 23-20, 23.1309 at Amendment 23-49, 23.1311 
at Amendment 49, 23.1321 at Amendment 49, 23.1322 at Amendment 43, 
23.1325 at Amendment 50, and 23.1543 at Amendment 50.

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

    West Star Aviation 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 GHz0....................................       2000        200

[[Page 32713]]

 
18 GHz-40GHz......................................        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 the 
Cessna 441. Should West Star Aviation apply at a later date for a 
supplemental type certificate to modify any other model on the same 
type certificate 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

    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 the Cessna 441 airplane modified by 
West Star Aviation to add two Honeywell/Ametek AM-250 digital air data 
computers.
    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 May 18, 2005.
John R. Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-10907 Filed 6-3-05; 8:45 am]
BILLING CODE 4910-13-P