[Federal Register Volume 66, Number 38 (Monday, February 26, 2001)]
[Rules and Regulations]
[Pages 11527-11529]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-4676]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM184; Special Conditions No. 25-174-SC]


Special Conditions: Airbus Industrie A300; 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 Airbus Industrie A300 
airplanes modified to an Electronic Cable Specialists design. 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

[[Page 11528]]

modification incorporates the installation of dual Electronic 
Horizontal Situation Indicators 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.

EFFECTIVE DATE: The effective date of these special conditions is 
February 16, 2001. Comments must be received on or before March 28, 
2001.

ADDRESSES: Comments on these special conditions may be mailed in 
duplicate to: Federal Aviation Administration, Transport Airplane 
Directorate, Attention: Rules Docket (ANM-114), Docket No. NM184, 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. NM184. 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: Meghan Gordon, FAA, Standardization 
Branch, ANM-113, Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone 
(425) 227-2138; 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 regulatory docket number 
and be submitted in duplicate to the address specified above. All 
communications recieved 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 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 these special conditions must include a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. NM184.'' The postcard will be date stamped and returned 
to the commenter.

Background

    On September 18, 2000, Electronic Cable Specialists, 5300 West 
Franklin Drive, Franklin WI, applied for a Supplemental Type 
Certificate (STC) to modify Airbus Industrie A300 airplanes. The Model 
A300 is a large transport category airplane. The Airbus A300 airplanes 
are powered by two General Electric Model CF6-50 turbofans with a 
maximum takeoff weight of 363,760 pounds. This aircraft operates with a 
pilot, copilot, and flight engineer and can hold up to 345 passengers. 
The modification incorporates the Universal Avionics Systems 
Corporation (UASC) EFI-550 Electronic Flight Instrument System. Dual 
EFI-550 flat panel displays will be installed, replacing existing 
electro-mechanical horizontal situation indicators (HSI's), as the 
primary navigation Display/HSI. 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, Electronic Cable Specialists 
must show that the Airbus Industrie A300 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 regulations included in the certification 
basis for the Airbus Industrie A300 airplanes include Title 14, Code of 
Federal Regulations (14 CFR) 21.29(a)(1), based upon France/German 
requirements of part 25 effective February 1, 1965, plus additional 
requirements listed in the type certificate data sheet that are not 
relevant to these special conditions.
    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 Industrie A300 airplanes 
modified to Electronic Cable Specialists design 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, these Airbus Industrie A300 airplanes must comply with the 
fuel vent and exhaust emission requirements of part 34 and the noise 
certification requirements of part 36.
    Special conditions, 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(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 
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

    As noted earlier, the Airbus Industrie A300 airplanes modified to 
Electronic Cable Specialists design will incorporate a new Electronic 
Horizontal Situation Indicator 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 that is equivalent to 
that intended by the regulations incorporated by reference, special 
conditions are needed for the Airbus Industrie A300 airplanes modified 
to Electronic Cable Specialists design. 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.

[[Page 11529]]

High-Intensity Radiated Fields (HIRF)

    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 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 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 following field 
strengths 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 
Airbus Industrie A300 airplanes modified to Electronic Cable 
Specialists design. 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 novel or unusual design features 
on the Airbus Industrie A300 airplanes modified to Electronic Cable 
Specialists design. 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. 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 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 Airbus Industrie A300 
airplanes modified to Electronic Cable Specialists design.
    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 February 16, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-4676 Filed 2-23-01; 8:45 am]
BILLING CODE 4910-13-M