[Federal Register Volume 68, Number 82 (Tuesday, April 29, 2003)]
[Rules and Regulations]
[Pages 22580-22582]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-10446]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM250; Special Conditions No. 25-233-SC]


Special Conditions: Israel Aircraft Industries Ltd. Model 1124 
Airplanes; High-Intensity Radiated Fields (HIRF)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for Israel Aircraft 
Industries Ltd. Model 1124 airplanes modified by Alternative Aviation 
Services. These modified airplanes will have a novel or unusual design 
feature when compared to the state of technology envisioned in the 
airworthiness standards for transport category airplanes. The 
modification incorporates the installation of dual Innovative Solutions 
& Support Air Data Display Units. 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 April 18, 
2003.
    Comments must be received on or before May 29, 2003.

ADDRESSES: Comments on these special conditions may be mailed in 
duplicate to: Federal Aviation Administration, Transport Airplane 
Directorate, Attn: Rules Docket (ANM-113), Docket No. NM250, 1601 Lind 
Avenue SW., Renton Washington, 98055-4056; or delivered in duplicate to 
the Transport Airplane Directorate at the above address. All comments 
must be marked: Docket No. NM250.

FOR FURTHER INFORMATION CONTACT: Greg Dunn, FAA, Airplane and Flight 
Crew Interface Branch, ANM-111, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056; telephone (425) 227-2799; facsimile (425) 227-
1320.

SUPPLEMENTARY INFORMATION:

FAA Determination as to Need for Public Process

    The FAA has determined that notice and opportunity for prior public 
comment is impracticable because these procedures would significantly 
delay certification of the airplane and thus delivery of the affected 
airplane. The FAA therefore finds that good cause exists for making 
these special conditions effective upon issuance; however the FAA 
invites interested persons to participate in this rulemaking by 
submitting written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data. We ask 
that you send us two copies of written comments.
    We will file in the docket all comments we receive, as well as a 
report summarizing each substantive public contact with FAA personnel 
concerning these special conditions. The docket is available for public 
inspection before and after the comment closing date. If you wish to 
review the docket in person, go to the address in the ADDRESSES section 
of this document between 7:30 a.m. and 4 p.m., Monday through Friday, 
except Federal holidays.
    We will consider all comments we receive on or before the closing 
date for comments. We will consider comments filed late if it is 
possible to do so without incurring expense or delay. We may change 
these special conditions based on comments we receive.
    If you want the FAA to acknowledge receipt of your comments on 
these special conditions, include with your comments a pre-addressed, 
stamped postcard on which the docket number appears. We will stamp the 
date on the postcard and mail it back to you.

Background

    On September 25, 2002, Alternative Aviation Services, 1661 Airport 
Road, Waterford, MI 48327, applied for a supplemental type certificate 
(STC) to modify Israel Aircraft Industries Ltd. Model 1124 airplanes 
approved under Type Certificate No. A2SW. The Model 1124 is a small 
transport category airplane powered by two Airesearch Manufacturing 
Company TFE-731-3-1G turbofan engines and has a maximum takeoff weight 
of 23,500 pounds. This airplane operates with a 2-pilot crew and can 
hold up to 10

[[Page 22581]]

passengers. The modification incorporates the installation of 
Innovative Solutions & Support Air Data Display Units (ADDU). The ADDU 
replaces the existing analog flight instrumentation and provides 
additional functional capability and redundancy in the system. The 
avionics/electronics and electrical systems installed in this airplane 
have the potential to be vulnerable to high-intensity radiated fields 
(HIRF) external to the airplane.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Amendment 21-69, effective 
September 16, 1991, Alternative Aviation Services must show that the 
Israel Aircraft Industries Ltd. Model 1124 airplane, as changed, 
continues to meet the applicable provisions of the regulations 
incorporated by reference in Type Certificate No. A2SW, or the 
applicable regulations in effect on the date of application for the 
change. [Subsequent changes have been made to Sec.  21.101 as part of 
Amendment 21-77, but those changes do not become effective until June 
10, 2003.] The regulations incorporated by reference in the type 
certificate are commonly referred to as the ``original type 
certification basis.'' The original type certification basis for the 
modified Israel Aircraft Industries Ltd. Model 1124 airplanes includes 
14 CFR part 25 as amended by Amendments 25-1 through 25-20, dated 
February 1, 1964, except for special conditions and exceptions noted in 
Type Certificate Data Sheet A2SW.
    If the Administrator finds that the applicable airworthiness 
regulations (that is, part 25, as amended) do not contain adequate or 
appropriate safety standards for the Israel Aircraft Industries Ltd. 
Model 1124 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 Israel Aircraft Industries Ltd. Model 1124 airplanes 
must comply with the fuel vent and exhaust emission requirements of 14 
CFR part 34 and the noise certification requirement of 14 CFR part 36.
    Special conditions, as defined in 14 CFR 11.19, are issued in 
accordance with Sec.  11.38 and become part of the type certification 
basis in accordance with Sec.  21.101(b)(2), Amendment 21-69, effective 
September 16, 1991.
    Special conditions are initially applicable to the model for which 
they are issued. Should Alternative Aviation Services apply at a later 
date for a supplemental type certificate to modify any other model 
included on Type Certificate No. A2SW to incorporate the same or 
similar novel or unusual design feature, these special conditions would 
also apply to the other model under the provisions of Sec.  
21.101(a)(1), Amendment 21-69, effective September 16, 1991.

Novel or Unusual Design Features

    As noted earlier, Israel Aircraft Industries Ltd. Model 1124 
airplanes modified by Alternative Aviation Services will incorporate 
systems comprised of dual Innovative Solutions & Support Air Data 
Display Units that will perform critical functions. These systems may 
be vulnerable to high-intensity radiated fields external to the 
airplane. The current airworthiness standards of part 25 do not contain 
adequate or appropriate safety standards for the protection of this 
equipment from the adverse effects of HIRF. Accordingly, this system is 
considered 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 Israel Aircraft Industries Ltd. Model 1124 
airplanes modified by Alternative Aviation Services. 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 
Israel Aircraft Industries Ltd. Model 1124 airplanes modified by 
Alternative Aviation Services. Should Alternative Aviation Services 
apply at a later date for a supplemental type certificate to modify any 
other model included on Type Certificate A2SW to incorporate the same 
or similar novel or unusual design feature, these special conditions 
would apply to that model as well

[[Page 22582]]

under the provisions of Sec.  21.101(a)(1), Amendment 21-69, effective 
September 16, 1991.

Conclusion

    This action affects only certain novel or unusual design features 
on Israel Aircraft Industries Ltd. Model 1124 airplanes modified by 
Alternative Aviation Services. 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. 
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 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

0
The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the supplemental type certification basis for Israel Aircraft 
Industries Ltd. Model 1124 airplanes modified by Alternative Aviation 
Services.
    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 Renton, Washington, on April 18, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-10446 Filed 4-28-03; 8:45 am]
BILLING CODE 4910-13-P