[Federal Register Volume 64, Number 195 (Friday, October 8, 1999)]
[Rules and Regulations]
[Pages 54761-54763]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-26372]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM164, Special Conditions No. 25-150-SC]


Special Conditions: Boeing 747-100, -100B, -100B SUD, -200B, -
200C, -200F, 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 Boeing Model 747-100, 
-100B, -100B SUD, -200B, -200C, -200F, and -300 series airplanes 
modified by Canard Aerospace Corporation. 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. 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 September 30, 
1999. Comments must be received on or before November 22, 1999.

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. NM164, 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. NM164. Comments may be inspected in the 
Rules Docket

[[Page 54762]]

weekdays, except Federal holidays, between 7:30 a.m. and 4 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. NM164.'' The postcard will 
be date stamped and returned to the commenter.

Background

    On April 2, 1999, Canard Aerospace Corporation, 13050 Pioneer 
Trail, Minneapolis, MN 55347, applied for a supplemental type 
certificate (STC) to modify Boeing Model 747-100, -100B, -100B SUD, -
200B, -200C, -200F, and -300 series airplanes approved under Type 
Certificate No. A20WE. The 747 series airplanes are 231 feet, 4 inches 
long and 195 feet, 8 inches wide. The height at vertical stabilizer to 
ground is 63 feet, 5 inches. The passenger load is 374 to 420 
passengers, and the range is from 5,290 to 6,600 miles. 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, Canard Aerospace must show 
that the Boeing Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, 
and -300 series airplanes, as changed, continue to meet the applicable 
provisions of the regulations incorporated by reference in Type 
Certificate No. A20WE, 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 Boeing Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, 
and -300 series airplanes include 14 CFR part 25, dated February 1, 
1965, with Amendments 1 through 40, as amended by Type Certificate Data 
Sheet (TCDS) A20WE.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25, as amended) do not contain adequate 
or appropriate safety standards for the Boeing Model 747-100, -100B, -
100B SUD, -200B, -200C, -200F, and -300 series airplanes because of 
novel or unusual design features, special conditions are prescribed 
under the provisions of Sec. 21.16.
    Special conditions, as appropriate, are issued in accordance with 
14 CFR 11.49, as required by Secs. 11.28 and 11.29, 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 Canard Aerospace apply at a later date for 
design change approval 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 Boeing Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, 
and -300 series 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 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 Boeing Model 747-100, -100B, -100B SUD, -
200B, -200C, -200F, and -300 series airplanes, which require that new 
electrical and electronic systems, such as the Honeywell Navigator 
System, 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, 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.

------------------------------------------------------------------------
                                                       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

[[Page 54763]]

 
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
2GHz-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 root-mean-square
  (rms) values.

Applicability

    As discussed above, these special conditions are applicable to 
Boeing 747-100, -100B, -100B SUD, -200B, -200C, -200F, and -300 series 
airplanes modified by Canard Aerospace. Should Canard Aerospace apply 
at a later date for design change approval 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 Boeing 747-100, 
-100B, -100B SUD, -200B, -200C, -200F, and -300 series airplanes 
modified by Canard Aerospace Corporation. 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 immediately. Therefore, these special conditions are being 
made effective 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 type certification basis for Boeing 747-100, -100B, -100B SUD, -
200B, -200C, -200F, and -300 series airplanes modified by Canard 
Aerospace Corporation.
    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.
    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, September 30, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service, ANM-100.
[FR Doc. 99-26372 Filed 10-7-99; 8:45 am]
BILLING CODE 4910-13-U