[Federal Register Volume 65, Number 70 (Tuesday, April 11, 2000)]
[Rules and Regulations]
[Pages 19294-19296]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-8849]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM171, Special Conditions No. 25-160-SC]


Special Conditions: Airbus A300 Model B2-1A, B2-1C, B4-2C, B2K-
3C, B4-103, B2-203, B4-203 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 A300 Model B2-
1A, B2-1C, B4-2C, B2K-3C, B4-103, B2-203, B4-203 airplanes modified by 
Electronic Cable Specialists. These airplanes will have novel and 
unusual design features when compared to the state of technology 
envisioned in the airworthiness standards for transport category 
airplanes. The installation of Honeywell Classic Navigator Systems will 
use advanced electronics when compared to the Inertial Navigation 
Systems. The applicable type certification regulations do not contain 
adequate or appropriate safety standards for the protection of this 
system 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 provided by the existing airworthiness standards.

DATES: The effective date of these special conditions is March 31, 
2000. Comments must be received on or before May 26, 2000.

ADDRESSES: Comments on these special conditions may be mailed in 
duplicate to: Federal Aviation Administration, Transport Airplane 
Directorate, Attn: Rules Docket (ANM-114), Docket No. NM171, 1601 Lind 
Avenue SW., Renton, Washington, 98055-4056; or delivered in duplicate 
to the Transport Airplane Directorate at the above address. Comments 
must be marked: Docket No. NM171. Comments may be inspected in the 
Rules Docket weekdays, except Federal holidays, between 7:30 a.m. and 
4:00 p.m.

FOR FURTHER INFORMATION CONTACT: Connie Beane, FAA, Standardization 
Branch, ANM-113, Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue SW., Renton, Washington, 98055-4056; 
telephone (425) 227-2796; facsimile (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA has determined that good cause exists for making these 
special conditions effective upon issuance; however, interested persons 
are invited to submit such written data, views, or arguments as they 
may desire. Communications should identify the docket and special 
conditions 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. These 
special conditions may be changed in light of the comments received. 
All comments submitted 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. Persons wishing the FAA to acknowledge receipt of their 
comments submitted in response to this request must submit with those 
comments a self-addressed, stamped postcard on which the following 
statement is made: ``Comments to Docket No. NM171.'' The postcard will 
be date stamped and returned to the commenter.

Background

    On November 29, 1999, Electronic Cable Specialists, 5300 West 
Franklin Drive, Franklin, Wisconsin 53132, applied for a Supplemental 
Type Certificate (STC) to modify Airbus A300 Model B2-1A, B2-1C, B4-2C, 
B2K-3C, B4-103, B2-203, B4-203 airplanes approved under Type 
Certificate No. A35EU. These are transport category airplanes with twin 
engines, and a seating capacity of up to 267 passengers. The 
modification incorporates the installation of Honeywell Classic 
Navigator Systems. Each system consists of a Honeywell HT-9100 
Navigation Management System, a Super Attitude Heading Reference 
System, and a Digital to Analog Adapter. These advanced systems use 
electronics to a far greater extent than the original Inertial 
Navigation Systems and may be more susceptible to electrical and 
magnetic interference. This disruption of signals could result in loss 
of attitude or present misleading information to the pilot.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Electronic Cable Specialists 
must show that Airbus A300 Model B2-1A, B2-1C, B4-2C, B2K-3C, B4-103, 
B2-203, B4-203 airplanes, as changed, continue to meet the applicable

[[Page 19295]]

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 
modified Airbus A300 Model B2-1A, B2-1C, B4-2C, B2K-3C, B4-103, B2-203, 
B4-203 airplanes includes 14 CFR part 25, dated February 1, 1965, as 
amended by Amendments 25-1 through 25-21.
    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 A300 Model B2-1A, B2-1C, 
B4-2C, B2K-3C, B4-103, B2-203, B4-203 airplanes because of novel or 
unusual design features, special conditions are prescribed under the 
provisions of Sec. 21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the Airbus A300 Model B2-1A, B2-1C, B4-2C, B2K-3C, B4-103, 
B2-203, B4-203 airplanes must comply with the part 25 fuel vent and 
exhaust emission requirements of 14 CFR part 34 and the part 25 noise 
certification requirements of 14 CFR part 36.
    Special conditions, as appropriate, are issued in accordance with 
Sec. 11.49, as required by Secs. 11.28 and 11.29(b), and become part of 
the type certification basis in accordance with Sec. 21.101(b)(2).
    Special conditions are initially applicable to the model for which 
they are issued. Should Electronic Cable Specialists apply at a later 
date 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, these special conditions would also 
apply to the other model under the provisions of Sec. 21.101(a)(1).

Novel or Unusual Design Features

    The Airbus A300 Model B2-1A, B2-1C, B4-2C, B2K-3C, B4-103, B2-203, 
B4-203 airplanes will incorporate a new navigation system, which was 
not available at the time of certification of these airplanes, that 
performs critical functions. This system may be vulnerable to high 
intensity radiated fields (HIRF) external to the airplane.

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 electrical and electronic 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 A300 Model B2-1A, B2-1C, B4-2C, 
B2K-3C, B4-103, B2-203, B4-203 airplanes, which require that new 
electrical and electronic systems, such as the Honeywell Navigator 
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

    With the trend toward increased power levels from ground-based 
transmitters, plus the advent of space and satellite communications 
coupled with electronic command and control of the airplane, the 
immunity of critical digital avionics 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 per meter root-mean-square (rms) 
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 following field 
strengths for the frequency ranges indicated. Both peak and average 
field strength components from the table are to be demonstrated.

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                    Field Strength (volts per meter)
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                   Frequency                        Peak       Average
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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
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 The field strengths are expressed in terms of peak of the root-mean-
  square (rms) over the complete modulation period.

Applicability

    As discussed above, these special conditions are applicable Airbus 
A300 Model B2-1A, B2-1C, B4-2C, B2K-3C, B4-103, B2-203, B4-203 
airplanes modified by Electronic Cable Specialists. Should Electronic 
Cable Specialists apply at a later date for a supplemental type 
certificate to modify any other model included on the same type 
certificate 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(a)(1).

Conclusion

    This action affects only certain design features on Airbus A300 
Model B2-1A, B2-1C, B4-2C, B2K-3C, B4-103, B2-203, B4-203 airplanes 
modified by Electronic Cable Specialists. 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 the special conditions for this airplane 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.

[[Page 19296]]

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 type certification basis Airbus A300 Model B2-1A, B2-1C, B4-2C, 
B2K-3C, B4-103, B2-203, B4-203 airplanes modified by Electronic Cable 
Specialists.
    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, March 31, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service, ANM-100.
[FR Doc. 00-8849 Filed 4-10-00; 8:45 am]
BILLING CODE 4910-13-P