[Federal Register: April 29, 2003 (Volume 68, Number 82)]
[Rules and Regulations]
[Page 22580-22582]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr29ap03-4]
-----------------------------------------------------------------------
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.
-----------------------------------------------------------------------
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