[Federal Register Volume 66, Number 20 (Tuesday, January 30, 2001)]
[Rules and Regulations]
[Pages 8162-8165]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-2037]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM182; Special Conditions No. 25-172-SC]


Special Conditions: Honeywell International, Inc.; Boeing Model 
747-300 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 747-300 
series airplanes modified by Honeywell

[[Page 8163]]

International, Inc. These modified airplanes will have novel or unusual 
design features associated with the installation of new navigation 
management system that includes electronic flight instrument system 
(EFIS) displays. The EFIS displays will use electrical and electronic 
systems 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 January 16, 
2001. Comments must be received on or before March 1, 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. NM182, 1601 
Lind Avenue SW., Renton, Washington 98055-4056; or delivered in 
duplicate to the Transport Airplane Directorate at that address. All 
comments must be marked: ``Docket No. NM182.'' 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: For information concerning the 
certification program for the Boeing Model 747-300 series airplanes 
modified by Honeywell International, Inc., contact: Ross Landes, 
Standardization Branch, ANM-113, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056; telephone (425) 227-145; fax (425) 227-1149.
    For information on the general subject of HIRF, contact: Massoud 
Sadeghi, Federal Aviation Administration, Transport Airplane 
Directorate, Airplane and Flight Crew Interface Branch, ANM-111, 1601 
Lind Avenue SW., Renton, Washington 98055-4056; telephone (425) 227-
2117; fax (425) 227-1320.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice and 
opportunity for prior public comment hereon are impracticable because 
these procedures would significantly delay issuance of the approval 
design 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.

Comments Invited

    Although these special conditions are being issued as final special 
conditions without prior public notice, 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 received on or before the closing date for comments will 
be considered by the Administrator. The 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 NM182.'' The postcard will be date stamped and returned to the 
commenter.

Background

    On October 20, 2000, Honeywell International Inc., 15001 N.E. 36th 
Street, P.O. Box 97001, Redmond, Washington 98073-9701, applied for a 
Supplemental Type Certificate (STC) for the Boeing Model 747-300 series 
airplanes operated by South African Airways (SAA). Honeywell plans to 
install upgraded avionics equipment on these airplanes. This equipment 
includes an electronic flight instrument system (EFIS) that displays 
attitude and heading information, and is manufactured by Astronautics. 
The modified airplanes are scheduled for certification in January 2001.
    The Astronautics EFIS provides a critical function that displays 
attitude and heading information. The EFIS must be designed and 
installed to ensure that its operation is not adversely affected by 
high intensity radiated fields (HIRF). These functions can be 
susceptible to disruption of both command and response signals as a 
result of electrical and magnetic interference caused by HIRF external 
to the airplane. This disruption of signals could result in loss of 
critical flight displays and annunciations, or could present misleading 
information to the pilot.
    The subject Boeing Model 747-300 series airplanes are four-engine 
transport category airplanes with a wingspan of 195 ft. 8 in. (59.6 m) 
and an overall length of 231 ft. 10.2 in. (70.6 m). They are 
essentially identical to the earlier Model 747-200 series, but have a 
stretched upper deck. Their maximum takeoff weight is 833,000 lbs. 
(374,850 kg) and typical cruise speed at 35,000 feet is Mach 0.85/565 
mph (910 km/h)

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Honeywell must show that the 
Boeing Model 747-300 series airplanes, as modified, 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 modification. The regulations 
incorporated by reference in the type certificate are commonly referred 
to as the ``original type certification basis.''
    The regulations incorporated by reference in Type Certificate No. 
A20WE for the Boeing Model 747-300 series airplanes are as follows:

1. Regulations

     14 CFR parts 1, 21, 34 (fuel vent and exhaust emission 
requirements), and 36 (noise certification requirements).
     14 CFR part 25, effective February 1, 1965.
     Amendments 25-1 through 25-8, plus 25-15, 25-17, 25-18, 
25-20, and 25-39 (transmitted by FAA letter dated February 4, 1977).
     Amendment 25-36, re: RB211 engine oil filter system 
compliance with Sec. 25.1019 and Sec. 25.1305(c)(7).
     Amendment 25-46, Sec. 25.803(d) (Transmitted by FAA letter 
to The Boeing Company, dated September 2, 1983. This is limited to all 
passenger configurations and 6/7 palet combi configurations.)

2. Special Conditions

     Special conditions summarized for record purposes as 
enclosed with FAA letter to The Boeing Company dated February 20, 1970.
     Special Conditions 4A, revised to apply to airplanes with 
the landing gear load evener system deleted (recorded as attachment to 
an FAA letter to The Boeing Company dated May 12, 1971).
     Special Conditions No. 25-61-NW-1 for occupancy not to 
exceed 32 passengers on the upper deck of airplanes with spiral 
staircase

[[Page 8164]]

(transmitted to The Boeing Company by FAA letter dated February 26, 
1975).
     Special Conditions No. 25-71-NW-3 for occupancy not to 
exceed 45 passengers on the upper deck of airplanes with straight 
segmented stairway (transmitted to The Boeing Company by FAA letter 
dated September 8, 1976).
     Modification of Special Conditions No. 25-71-NW-3 for 
occupancy not to exceed 110 passengers on the upper deck of airplanes 
with segmented stairway (transmitted to The Boeing Company by FAA 
letter dated August 3, 1981).
     Special Conditions No. 25-77-NW-4--modification of the 
autopilot system to approve the airplane for use of the system under 
category IIIb landing conditions (transmitted to The Boeing Company by 
FAA letter dated July 8, 1977).
     Special Condition No. 25-ANM-16 for installation of an 
overhead crew rest area, occupancy not to exceed 10 crewmembers. (The 
FAA-approved procedures required for compliance with paragraph 13 of 
the Special Condition are located in Boeing Document D926U303, Appendix 
D.)

3. Exemptions From 14 CFR Part 25

      Exemption No. 1013A, dated December 24, 1969.
      Exemption No. 1870D, dated April 3, 1991.
      Exemption No. 3035 dated September 9, 1980.

4. Compliance With the Following Optional Requirements

      Sec. 25.801, ``Ditching.''
      Sec. 25.1419, ``Ice protection.''

5. Equivalent Safety Findings With Respect to the Following Regulations

      Sec. 25.773(b)(2)(i), amendments 25-1 through 25-67, 
``Pilot compartment view.''
      Sec. 25.811(f), ``Emergency exit marking.''
      Sec. 25.812(k)(2), ``Emergency lighting.''
      Sec. 25.815, ``Width of aisle.''
      Sec. 25.1415(d) ``Ditching equipment'' [re: Emergency 
Locator Transmitter (ELT)].
    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 747-300 series 
airplanes modified by Honeywell because of a novel or unusual design 
feature, special conditions are prescribed under the provisions of 
Sec. 21.16.
    Special conditions, as appropriate, are issued in accordance with 
Sec. 11.19, as required by Sec. 11.38, and become part of the 
airplane's type certification basis in accordance with 
Sec. 21.101(b)(2).
    The special conditions approved in this new document will form an 
additional part of the type certification basis for these airplanes.
    Special conditions are initially applicable to the model for which 
they are issued. Should Honeywell apply for a supplemental type 
certificate to modify any other model included on the same type 
certificate to incorporate the same novel or unusual design features, 
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 747-300 series airplanes modified by Honeywell 
will incorporate the Astronautics EFIS system, which performs critical 
functions. The EFIS system contains electronic equipment for which the 
current airworthiness standards (14 CFR part 25) do not contain 
adequate or appropriate safety standards that address protecting this 
equipment from the adverse effects of HIRF. This system may be 
vulnerable to HIRF external to the airplane. Accordingly, this system 
is considered to be a novel or unusual design feature.

Discussion

    There is no specific regulation that addresses the requirements for 
protection of 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 that is equivalent to 
that intended by the regulations incorporated by reference, special 
conditions are needed for the Boeing Model 747-300 airplanes modified 
by Honeywell to include the Astronautics EFIS system. These special 
conditions will require that this system, which performs 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, and the 
use of composite material in the airplane structure, 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, alternatively, 
paragraph 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.

Or

    2. A threat external to the airframe for both of the following 
field strengths for the frequency ranges indicated. Both peak and 
average field strength components from Table 1 are to be demonstrated.

                                 Table 1
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                                                       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 in Table 1 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.

[[Page 8165]]

Applicability

    As discussed above, these special conditions are applicable to the 
Boeing Model 747-300 series airplanes modified by Honeywell 
International, Inc., to include the Astronautics EFIS system. Should 
Honeywell apply at a later date for a supplemental type certificate to 
modify any other model included on Type Certificate A20WE to 
incorporate the same novel or unusual design features, 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 Boeing Model 747-300 series airplanes modified by Honeywell 
International, Inc. 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 airplanes.
    As stated previously, the substance of the 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 the Boeing Model 747-300 
series airplanes modified by Honeywell International, Inc.
    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 January 16, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-2037 Filed 1-29-01; 8:45 am]
BILLING CODE 4910-13-U