[Federal Register Volume 69, Number 3 (Tuesday, January 6, 2004)]
[Rules and Regulations]
[Pages 490-492]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-239]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM272; Special Conditions No. 25-256-SC]


Special Conditions: Airbus Model A300 B4-600, -B4-600R, -F4-600R 
Series Airplanes; and Model A310-200 and -300 Series 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 Airbus model A300 B4-
600, -B4-600R, and -F4-600R (collectively called A300-600) series 
airplanes; and A310-200 and -300 series airplanes modified by Canard 
Aerospace Corporation. 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 Honeywell 
Air Data Inertial Reference Units (ADIRU) that perform critical 
functions. 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 December 29, 
2003. Comments must be received on or before February 5, 2004.

ADDRESSES: Comments on these special conditions may be mailed in 
duplicate to: Federal Aviation Administration, Transport Airplane 
Directorate, Attention: Rules Docket (ANM-113), Docket No. NM272, 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. NM272.

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:

Comments Invited

    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 
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; 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 preamble 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 the 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 November 14, 2003, Canard Aerospace Corporation, 13050 Pioneer 
Trail, Eden Prairie, Minnesota 55347, applied for a Supplemental Type 
Certificate (STC) to modify Airbus model A300-600 series; and A310-200, 
-300 series airplanes approved under Type Certificate No. A35EU. The 
Airbus A300 and A310 series airplanes are a large transport category 
airplane. The wide body twin-engine, twin-aisle aircraft family offers 
configurations for 220 to 360 seats or freighter versions. These 
airplanes have maximum take-off weights of up to 378,530 pounds and are 
powered by either General Electric CF6-80C2 or Pratt & Whitney JT9D/
PW4000 turbofan engines. The modification incorporates the installation 
of the Honeywell Air Data Inertial Reference Units (ADIRU) to replace 
aging Inertial Reference Units (IRU). The ADIRU provide flight critical 
functions by determining the airplane's attitude, heading, and 
position. 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, Canard Aerospace must show 
the Airbus A300 and A310 series airplanes, as changed, continue to meet 
the applicable provisions of the regulations incorporated by reference 
in Type Certificate No. A35EU, 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 certification basis for the 
Airbus A300-600 series airplanes includes 14 CFR part 25, dated 
February 1, 1965, as amended by Amendments 25-1 through 25-74; 14 CFR 
part 36 effective December 1, 1969, including Amendments 36-1 through 
36-22. The certification basis for the modified Airbus A310-200 and -
300 series airplanes includes 14 CFR part 25, dated February 1, 1965, 
as amended by Amendments 25-1 through 25-54; 14 CFR part 36 effective 
December 1, 1969, including Amendments 36-1 through 36-12. In addition 
to the basis cited for all of the above models, the certification basis 
includes special conditions, exceptions, and variations noted in Type 
Certificate Data Sheet (TCDS) A35EU.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., part 25, as amended) do not contain adequate or 
appropriate safety standards for the Airbus model A300-600 series, and 
A310-200 and -300 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

[[Page 491]]

conditions, the Airbus model A300-600 series, and A310-200 and -300 
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 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.
    Special conditions are initially applicable to the model for which 
they are issued. Should Canard Aerospace apply at a later date for a 
supplemental type certificate to modify any other model included on 
Type Certificate No. A35EU 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.

Novel or Unusual Design Features

    As noted earlier, the Airbus model A300-600 series, and A310-200 
and -300 series airplanes modified by Canard Aerospace will incorporate 
new Honeywell Air Data Inertial Reference Units (ADIRU) that will 
perform critical functions. This system 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 the Airbus model A300 and A310 series 
airplanes modified by Canard Aerospace. 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
                       Frequency                             meter)
                                                       -----------------
                                                          Peak   Average
------------------------------------------------------------------------
10 kHz-100 kHz........................................       50       50
100kHz-500 kHz........................................       50       50
500kHz-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 
Airbus model A300-600 series, and A310-200 and -300 series airplanes 
modified by Canard Aerospace Corporation. Should Canard Aerospace apply 
at a later date for a supplemental type certificate to modify any other 
model included on Type Certificate No. A35EU to incorporate the same or 
similar 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 Airbus model A300-600 series, and A310-200 and -300 series airplanes 
modified by Canard Aerospace. 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. 
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.
    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 the Airbus model A300-600 
series, A310-200 series, and A310-300 series airplanes modified by 
Canard Aerospace Corporation.
    1. Protection from Unwanted Effects of High-Intensity Radiated 
Fields

[[Page 492]]

(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 December 30, 2003.
Mike Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-239 Filed 1-5-04; 8:45 am]
BILLING CODE 4910-13-P