Special Conditions: Avcon Industries, Inc.; Learjet Model 23 Series Airplanes; High-Intensity Radiated Fields (HIRF), 49987-49989 [E6-13995]

Download as PDF Federal Register / Vol. 71, No. 164 / Thursday, August 24, 2006 / Rules and Regulations for conducting producer referenda and 7 CFR part 717 is obsolete. Executive Order 12866 This rule related to internal agency management. Therefore, pursuant to 5 U.S.C. 553, notice of proposed rulemaking and opportunity for comment are not required, and this rule may be made effective less than 30 days after publication in the Federal Register. Further, because this rule relates to internal agency management, it is exempt from the provisions of Executive Order Nos. 12291 and 12866. Finally, this action is not a rule as defined by the Regulatory Flexibility Act, 5 U.S.C. 601, et seq., and is therefore exempt from the provisions of that Act. Accordingly, as authorized by section 808 of the Small Business Regulatory Enforcement Fairness Act of 1996, 5 U.S.C. 808, this rule may be made effective upon publication. Paperwork Reduction Act This rule does not affect any information collections. List of Subjects in 7 CFR Part 717 Agricultural Commodities, Allotments, Price support programs, Quotas, Tobacco. PART 717—[REMOVED] Accordingly, under the authority of 5 U.S.C. 301, 7 CFR Chapter VII is amended by removing part 717. I Signed at Washington, DC on August 9, 2006. Teresa C. Lasseter, Administrator, Farm Service Agency. [FR Doc. 06–7159 Filed 8–23–06; 8:45 am] BILLING CODE 3410–05–M DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 23 [Docket No. CE258; Special Conditions No. 23–198–SC] Special Conditions: Avcon Industries, Inc.; Learjet Model 23 Series Airplanes; High-Intensity Radiated Fields (HIRF) Federal Aviation Administration (FAA), DOT. ACTION: Final special conditions; request for comments. rmajette on PROD1PC67 with RULES1 AGENCY: SUMMARY: These special conditions are issued to Avcon Industries, Inc., for the Learjet Model 23 series airplanes modified by Avcon Industries, Inc. This airplane as modified by Avcon VerDate Aug<31>2005 15:14 Aug 23, 2006 Jkt 208001 Industries, Inc., will have a novel or unusual design feature associated with the installation of a new Reduced Vertical Separation Minimum (RVSM) air data system. The applicable airworthiness regulations do not contain adequate or appropriate safety 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 that established by the existing airworthiness standards. DATES: The effective date of these special conditions is August 17, 2006. Comments must be received on or before September 25, 2006. ADDRESSES: Comments on these special conditions may be mailed in duplicate to: Federal Aviation Administration, Regional Counsel, ACE–7, Attention: Rules Docket CE258, 901 Locust, Room 506, Kansas City, Missouri 64106 or delivered in duplicate to the Regional Counsel at the above address. Comments must be marked: CE258. 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: Ervin Dvorak, Federal Aviation Administration, Aircraft Certification Service, Small Airplane Directorate, ACE–111, 901 Locust, Room 301, Kansas City, Missouri 64106; 816–329– 4123; fax 816–329–4090. SUPPLEMENTARY INFORMATION: The FAA has determined that notice and opportunity for prior public comment hereon are impracticable because these procedures would significantly delay issuance of the approval design and thus delivery of the affected aircraft. In addition, the substance of these special conditions has been subject to the public comment process in several prior instances with no substantive comments received. The FAA therefore finds that good cause exists for making these special conditions effective on 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 PO 00000 Frm 00009 Fmt 4700 Sfmt 4700 49987 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 CE258.’’ The postcard will be date stamped and returned to the commenter. Background On June 26, 2006, Avcon Industries, Inc.; P.O. Box 748; Newton, Kansas 67114, applied for a supplemental type certificate (STC) to modify Learjet Model 23 series airplanes currently approved under Type Certificate (TC) No. A5CE. The Learjet 23 series airplanes are normal category airplanes powered by two turbojet engines, with a maximum takeoff weight of 12,500 pounds. These airplanes operate with a 2-person crew and can seat up to 8 passengers. The proposed modification is the installation of an Innovative Solutions & Support Air Data Display Units and Analog Interface Unit. The avionics/electronics and electrical systems installed in this airplane have the potential to be vulnerable to HIRF external to the airplane. Type Certification Basis Under the provisions of § 21.101, Avcon Industries, Inc., must show that the Learjet Model 23 series airplanes, as changed, continue to meet the applicable provisions of the regulations incorporated by reference in Type Certificate No. A5CE, 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.’’ The regulations incorporated by reference in the Type Certificate No. A5CE for the Learjet Model 23 series airplanes includes Civil Air Regulations (CAR), part 3, effective May 15, 1956, as amended by Amendments 3–1 through 3–8, plus special conditions set forth in FAA letter to Learjet, dated November 12, 1963, and Amendment No. 1, dated July 31, 1964, and No. 2, dated March 14, 1966, and Exception No. 352 from compliance with CAR 3.74(a)(2) and (3) for ground operation at a maximum weight of 12,750 pounds. If the Administrator finds that the applicable airworthiness regulations (i.e., part 23, as amended) do not E:\FR\FM\24AUR1.SGM 24AUR1 49988 Federal Register / Vol. 71, No. 164 / Thursday, August 24, 2006 / Rules and Regulations contain adequate or appropriate safety standards for the Learjet Model 23 series airplanes because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16. In addition to the applicable airworthiness regulations and special conditions, the Learjet Model 23 series airplanes must comply with the fuel vent and exhaust emission requirements of 14 CFR part 34 and the noise certification requirements of 14 CFR part 36. Special conditions, as appropriate, as defined in § 11.19, are issued in accordance with § 11.38, 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 Avcon Industries, Inc., apply for a supplemental type certificate to modify any other model included on TC No. A5CE to incorporate the same or a similar novel or unusual design feature, these special conditions would also apply to the other model under the provisions of § 21.101. rmajette on PROD1PC67 with RULES1 Novel or Unusual Design Features The Learjet Model 23 series airplanes, as modified by Avcon Industries, Inc., will incorporate an Innovative Solutions & Support Air Data Display Units and Analog Interface Unit. The Innovative Solutions & Support Air Data Display Units and Analog Interface Unit perform critical functions. These systems may be vulnerable to HIRF external to the airplane. The current airworthiness standards of part 23 do not contain adequate or appropriate safety standards for the protection of this equipment from the adverse effects of HIRF. Therefore, we consider this system to be a novel or unusual design feature. Discussion There is no specific regulation that addresses protection requirements for electrical and electronic systems from HIRF. Increased power levels from ground-based radio transmitters and the growing use of sensitive avionics/ electronics and electrical systems to command and control airplanes have made it necessary to provide adequate protection. To ensure that a level of safety is achieved equivalent to that intended by the regulations incorporated by reference, special conditions are needed for the Learjet Model 23 series airplanes as modified by Avcon Industries, Inc. These special conditions require that new avionics/electronics and electrical systems that perform critical functions be designed and installed to preclude VerDate Aug<31>2005 15:14 Aug 23, 2006 Jkt 208001 component damage and interruption of function due to both the direct and indirect effects of HIRF. Frequency Field strength (volts per meter) Peak Average High-Intensity Radiated Fields (HIRF) With the trend toward increased power levels from ground-based transmitters, and the advent of space and satellite communications, coupled with electronic command and control of the airplane, the immunity of critical avionics/electronics and electrical systems to HIRF must be established. It is not possible to precisely define the HIRF to which the airplane will be exposed in service. There is also uncertainty concerning the effectiveness of airframe shielding for HIRF. Furthermore, coupling of electromagnetic energy to cockpitinstalled equipment through the cockpit window apertures is undefined. Based on surveys and analysis of existing HIRF emitters, an adequate level of protection exists when compliance with the HIRF protection special condition is shown with either paragraph 1 or 2 below: 1. A minimum threat of 100 volts rms (root-mean-square) per meter electric field strength from 10 KHz to 18 GHz. a. The threat must be applied to the system elements and their associated wiring harnesses without the benefit of airframe shielding. b. Demonstration of this level of protection is established through system tests and analysis. 2. A threat external to the airframe of the field strengths identified in the table below for the frequency ranges indicated. Both peak and average field strength components from the table are to be demonstrated. Field strength (volts per meter) Frequency 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 PO 00000 Frm 00010 Fmt 4700 Average 18 GHz–40 GHz 600 200 The field strengths are expressed in terms of peak of the root-mean-square (rms) over the complete modulation period. The threat levels identified above are the result of an FAA review of existing studies on the subject of HIRF, in light of the ongoing work of the Electromagnetic Effects Harmonization Working Group of the Aviation Rulemaking Advisory Committee. Applicability As discussed above, these special conditions are applicable to Learjet Model 23 series airplanes modified by Avcon Industries, Inc. Should Avcon Industries, Inc., apply later for an STC to modify any other model included on TC No. A5CE to incorporate the same novel or unusual design feature, these 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 the Learjet 23 series airplanes modified by Avcon Industries, Inc. 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 procedure 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. 50 50 50 50 100 50 50 50 100 50 50 50 100 100 100 100 700 700 2000 3000 3000 1000 3000 2000 50 100 200 200 200 200 300 200 Sfmt 4700 E:\FR\FM\24AUR1.SGM 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: 24AUR1 Federal Register / Vol. 71, No. 164 / Thursday, August 24, 2006 / Rules and Regulations 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 Learjet Model 23 series airplanes modified by Avcon Industries, Inc. 1. Protection from Unwanted Effects of High-Intensity Radiated Fields (HIRF). Each electrical and electronic system that performs critical functions must be designed and installed to ensure that the operation and operational capability of these systems to perform critical functions are not adversely affected when the airplane is exposed to high-intensity radiated fields. 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 August 17, 2006. David R. Showers, Acting Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. E6–13995 Filed 8–23–06; 8:45 am] BILLING CODE 4910–13–P NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 14 CFR Part 1213 Notice: (06–060) RIN 2700–AD25 Release of Information to News and Information Media rmajette on PROD1PC67 with RULES1 Effective Date: August 24, 2006. R. Andrew Falcon, Associate General Counsel, General Law Practice Group, Office of the General Counsel, NASA VerDate Aug<31>2005 15:14 Aug 23, 2006 Jkt 208001 PART 1213—RELEASE OF INFORMATION TO NEWS AND INFORMATION MEDIA Sec. 1213.100 Scope. 1213.101 Applicability. 1213.102 Policy. 1213.103 Responsibilities. 1213.104 Public information coordination and concurrence. 1213.105 Interviews. 1213.106 Preventing release of classified information to the media. 1213.107 Preventing unauthorized release of sensitive but unclassified (SBU) information/material to the news media. 1213.108 Multimedia materials. 1213.109 News releases concerning international activities. § 1213.100 SUMMARY: The National Aeronautics and Space Administration (NASA) is amending NASA regulations on release of information to news and information media. These amendments will establish NASA policy, responsibility, and procedure for providing information to news media on NASA activities. FOR FURTHER INFORMATION CONTACT: List of Subjects in 14 CFR Part 1213 Administrative practice and procedure, News media. I For the reasons set out in the preamble, NASA revises part 1213 of title 14 of the Code of Federal Regulations to read as follows: Authority: 42 U.S.C. 2473(a)(3). National Aeronautics and Space Administration. ACTION: Final rule. AGENCY: DATES: Headquarters, telephone (202) 358– 2465, fax (202) 358–4355. SUPPLEMENTARY INFORMATION: These amendments set forth procedures for internal review of public information, updates the designations of officials responsible for the accuracy of information contained in press releases and other forms of public information, and provides guidance to employees on authorities governing the release of information. Since this action concerns matters of internal Agency organization, practice, and procedure, no public comment period is required, and this rule becomes effective on the date of publication. This rule is not subject to the Regulatory Flexibility Act (5 U.S.C. chapter 6) since it will not have a significant impact on a substantial number of small entities. Finally, this rule is not a major Federal action as defined in Executive Order 12866. Scope. This part sets forth policy governing the release of public information, which is defined as information in any form provided to news and information media, especially information that has the potential to generate significant media or public interest or inquiry. Examples include, but are not limited to, press releases, media advisories, news features, and Web postings. Not included under this definition are scientific and technical reports, Web postings designed for technical or scientific interchange, and technical information presented at professional meetings or in professional journals. PO 00000 Frm 00011 Fmt 4700 Sfmt 4700 § 1213.101 49989 Applicability. (a) This policy applies to NASA Headquarters, NASA Centers, and Component Facilities. (b) In the event of any conflict between this policy and any other NASA policy, directive, or regulation, this policy shall govern and supersede any previous issuance or directive. (c) The requirements of this part do not apply to the Office of Inspector General regarding its activities. § 1213.102 Policy. (a) NASA, a scientific and technical Agency, is committed to a culture of openness with the media and public that values the free exchange of ideas, data, and information as part of scientific and technical inquiry. Scientific and technical information from or about Agency programs and projects will be accurate and unfiltered. (b) Consistent with NASA statutory responsibility, NASA will ‘‘provide for the widest practicable and appropriate dissemination of information concerning its activities and the results thereof.’’ Release of public information concerning NASA activities and the results of NASA activities will be made in a timely, equitable, accurate, and complete manner. (c) To ensure timely release of information, NASA will endeavor to ensure cooperation and coordination among the Agency’s scientific, engineering, and public affairs communities. (d) In keeping with the desire for a culture of openness, NASA employees may, consistent with this policy, speak to the press and the public about their work. (e) This policy does not authorize or require disclosure of information that is exempt from disclosure under the Freedom of Information Act (5 U.S.C. 552) or otherwise restricted by statute, regulation, Executive Order, or other Executive Branch policy or NASA policy (e.g., OMB Circulars, NASA Policy Directives). Examples of information not releasable under this policy include, without limitation, information that is, or is marked as, classified information, procurement sensitive information, information subject to the Privacy Act, other sensitive but unclassified information, and information subject to privilege, such as pre-decisional information or attorney-client communications. § 1213.103 Responsibilities. (a) The Assistant Administrator for Public Affairs is responsible for developing and administering an integrated Agency-wide E:\FR\FM\24AUR1.SGM 24AUR1

Agencies

[Federal Register Volume 71, Number 164 (Thursday, August 24, 2006)]
[Rules and Regulations]
[Pages 49987-49989]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-13995]


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

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE258; Special Conditions No. 23-198-SC]


Special Conditions: Avcon Industries, Inc.; Learjet Model 23 
Series Airplanes; 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 Avcon Industries, Inc., 
for the Learjet Model 23 series airplanes modified by Avcon Industries, 
Inc. This airplane as modified by Avcon Industries, Inc., will have a 
novel or unusual design feature associated with the installation of a 
new Reduced Vertical Separation Minimum (RVSM) air data system. The 
applicable airworthiness regulations do not contain adequate or 
appropriate safety 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 that established by the existing airworthiness standards.

DATES: The effective date of these special conditions is August 17, 
2006. Comments must be received on or before September 25, 2006.

ADDRESSES: Comments on these special conditions may be mailed in 
duplicate to: Federal Aviation Administration, Regional Counsel, ACE-7, 
Attention: Rules Docket CE258, 901 Locust, Room 506, Kansas City, 
Missouri 64106 or delivered in duplicate to the Regional Counsel at the 
above address. Comments must be marked: CE258. 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: Ervin Dvorak, Federal Aviation 
Administration, Aircraft Certification Service, Small Airplane 
Directorate, ACE-111, 901 Locust, Room 301, Kansas City, Missouri 
64106; 816-329-4123; fax 816-329-4090.

SUPPLEMENTARY INFORMATION:
    The FAA has determined that notice and opportunity for prior public 
comment hereon are impracticable because these procedures would 
significantly delay issuance of the approval design and thus delivery 
of the affected aircraft. In addition, the substance of these special 
conditions has been subject to the public comment process in several 
prior instances with no substantive comments received. The FAA 
therefore finds that good cause exists for making these special 
conditions effective on 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 CE258.'' The postcard will be date stamped and returned 
to the commenter.

Background

    On June 26, 2006, Avcon Industries, Inc.; P.O. Box 748; Newton, 
Kansas 67114, applied for a supplemental type certificate (STC) to 
modify Learjet Model 23 series airplanes currently approved under Type 
Certificate (TC) No. A5CE. The Learjet 23 series airplanes are normal 
category airplanes powered by two turbojet engines, with a maximum 
takeoff weight of 12,500 pounds. These airplanes operate with a 2-
person crew and can seat up to 8 passengers. The proposed modification 
is the installation of an Innovative Solutions & Support Air Data 
Display Units and Analog Interface Unit. The avionics/electronics and 
electrical systems installed in this airplane have the potential to be 
vulnerable to HIRF external to the airplane.

Type Certification Basis

    Under the provisions of Sec.  21.101, Avcon Industries, Inc., must 
show that the Learjet Model 23 series airplanes, as changed, continue 
to meet the applicable provisions of the regulations incorporated by 
reference in Type Certificate No. A5CE, 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.'' The regulations 
incorporated by reference in the Type Certificate No. A5CE for the 
Learjet Model 23 series airplanes includes Civil Air Regulations (CAR), 
part 3, effective May 15, 1956, as amended by Amendments 3-1 through 3-
8, plus special conditions set forth in FAA letter to Learjet, dated 
November 12, 1963, and Amendment No. 1, dated July 31, 1964, and No. 2, 
dated March 14, 1966, and Exception No. 352 from compliance with CAR 
3.74(a)(2) and (3) for ground operation at a maximum weight of 12,750 
pounds.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., part 23, as amended) do not

[[Page 49988]]

contain adequate or appropriate safety standards for the Learjet Model 
23 series airplanes because of a novel or unusual design feature, 
special conditions are prescribed under the provisions of Sec.  21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the Learjet Model 23 series airplanes must comply with the 
fuel vent and exhaust emission requirements of 14 CFR part 34 and the 
noise certification requirements of 14 CFR part 36.
    Special conditions, as appropriate, as defined in Sec.  11.19, are 
issued in accordance with Sec.  11.38, 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 Avcon Industries, Inc., apply for a 
supplemental type certificate to modify any other model included on TC 
No. A5CE to incorporate the same or a similar novel or unusual design 
feature, these special conditions would also apply to the other model 
under the provisions of Sec.  21.101.

Novel or Unusual Design Features

    The Learjet Model 23 series airplanes, as modified by Avcon 
Industries, Inc., will incorporate an Innovative Solutions & Support 
Air Data Display Units and Analog Interface Unit. The Innovative 
Solutions & Support Air Data Display Units and Analog Interface Unit 
perform critical functions. These systems may be vulnerable to HIRF 
external to the airplane. The current airworthiness standards of part 
23 do not contain adequate or appropriate safety standards for the 
protection of this equipment from the adverse effects of HIRF. 
Therefore, we consider this system to be a novel or unusual design 
feature.

Discussion

    There is no specific regulation that addresses protection 
requirements for electrical and electronic systems from HIRF. Increased 
power levels from ground-based radio transmitters and the growing use 
of sensitive avionics/electronics and electrical systems to command and 
control airplanes have made it necessary to provide adequate 
protection.
    To ensure that a level of safety is achieved equivalent to that 
intended by the regulations incorporated by reference, special 
conditions are needed for the Learjet Model 23 series airplanes as 
modified by Avcon Industries, Inc. These special conditions require 
that new avionics/electronics and electrical systems that perform 
critical functions be designed and installed to preclude component 
damage and interruption of function due to both the direct and indirect 
effects of HIRF.

High-Intensity Radiated Fields (HIRF)

    With the trend toward increased power levels from ground-based 
transmitters, and the advent of space and satellite communications, 
coupled with electronic command and control of the airplane, the 
immunity of critical avionics/electronics and electrical systems to 
HIRF must be established.
    It is not possible to precisely define the HIRF to which the 
airplane will be exposed in service. There is also uncertainty 
concerning the effectiveness of airframe shielding for HIRF. 
Furthermore, coupling of electromagnetic energy to cockpit-installed 
equipment through the cockpit window apertures is undefined. Based on 
surveys and analysis of existing HIRF emitters, an adequate level of 
protection exists when compliance with the HIRF protection special 
condition is shown with either paragraph 1 or 2 below:
    1. A minimum threat of 100 volts rms (root-mean-square) per meter 
electric field strength from 10 KHz to 18 GHz.
    a. The threat must be applied to the system elements and their 
associated wiring harnesses without the benefit of airframe shielding.
    b. Demonstration of this level of protection is established through 
system tests and analysis.
    2. A threat external to the airframe of the field strengths 
identified in the table below for the frequency ranges indicated. Both 
peak and average field strength components from the table are to be 
demonstrated.

------------------------------------------------------------------------
                                                 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 of the root-mean-
  square (rms) over the complete modulation period.

    The threat levels identified above are the result of an FAA review 
of existing studies on the subject of HIRF, in light of the ongoing 
work of the Electromagnetic Effects Harmonization Working Group of the 
Aviation Rulemaking Advisory Committee.

Applicability

    As discussed above, these special conditions are applicable to 
Learjet Model 23 series airplanes modified by Avcon Industries, Inc. 
Should Avcon Industries, Inc., apply later for an STC to modify any 
other model included on TC No. A5CE to incorporate the same novel or 
unusual design feature, these 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 the Learjet 23 series airplanes modified by Avcon Industries, Inc. 
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 procedure 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:


[[Page 49989]]


    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 Learjet Model 23 series airplanes 
modified by Avcon Industries, Inc.
    1. Protection from Unwanted Effects of High-Intensity Radiated 
Fields (HIRF). Each electrical and electronic system that performs 
critical functions must be designed and installed to ensure that the 
operation and operational capability of these systems to perform 
critical functions are not adversely affected when the airplane is 
exposed to high-intensity radiated fields.
    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 August 17, 2006.
David R. Showers,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-13995 Filed 8-23-06; 8:45 am]
BILLING CODE 4910-13-P