[Federal Register Volume 66, Number 216 (Wednesday, November 7, 2001)]
[Rules and Regulations]
[Pages 56197-56199]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-27986]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM199; Special Conditions No. 25-188-SC]


Special Conditions: Boeing 747-200/-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 747-200/-
300 series airplanes modified by Hollingsead International, Inc. 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 new Liquid Crystal Flight Instruments 
as Attitude Directional Indicators (ADI), the Horizontal Situation 
Indicators (HSI) and Engine Display Interface System (EDIS). The liquid 
crystal flight instruments will utilize 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 October 25, 
2001. Comments must be received on or before December 24, 2001.

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. NM199, 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. NM199. 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: 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-
1149.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice and 
opportunity for prior public comment hereon are impracticable because 
these procedures would significantly delay certification of the 
airplane and thus delivery of the affected aircraft. The FAA therefore 
finds that good cause exists for making these special conditions 
effective upon issuance.

Comments Invited

    Interested persons are invited to submit such written data, views, 
or arguments as they may desire. Communications should identify the 
rules docket number and be submitted in duplicate to the address 
specified above. The Administrator will consider all communications 
received on or before the closing date for comments. 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. 
Persons wishing the FAA to acknowledge receipt of their comments 
submitted in response to these special conditions must include with 
those comments a self-addressed, stamped postcard on which the 
following statement is made: ``Comments to Docket No. NM199.'' The 
postcard will be date stamped and returned to the commenter.

Background

    On October 13, 1997, Hollingsead International, Inc., 7416 
Hollister Avenue, Goleta, California 93117-2538, applied for a 
Supplemental Type Certificate (STC) for the Boeing Model 747-200/-300 
series airplanes. The Boeing Model 747-200/-300 series airplanes are 
equipped with four CF650E2 turbofan engines. The aircraft have a crew 
of three with additional seating for one, consisting of a jump seat in 
the cockpit. The aircraft are operated by KLM Royal Dutch airlines in 
``freighter,'' ``combi,'' and ``full

[[Page 56198]]

passenger'' configurations. The Boeing 747-200/-300 airplanes will 
incorporate Smiths Industries 5-ATI liquid crystal flight instruments. 
The modified airplanes are scheduled for certification in November 
2001.
    The functions of the liquid crystal flight instruments 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.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Hollingsead International, 
Inc, must show that the Boeing 747-200/-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 regulations included in the certification 
basis for the Boeing Model 747-200/-300 series airplanes include 14 CFR 
part 25, as amended by Amendment 25-1 through Amendment 25-91.
    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 Boeing Model 747-200/300 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 
conditions, the Boeing Model 747-200/-300 series airplanes must comply 
with the fuel vent and exhaust emission requirement of 14 CFR part 34 
and the noise certification requirement of 14 CFR part 36.
    Special conditions, as defined in Sec. 11.19, are issued in 
accordance with Sec. 11.38 and become part of the airplane's 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 the applicant 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 747-200/-300 series airplanes will incorporate the 
Smiths Industries 5-ATI liquid crystal flight instruments as ADI, HSI 
and EDIS, which perform critical functions. The liquid crystal flight 
instruments contain 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. These instruments may be vulnerable 
to HIRF external to the airplane. Accordingly, these instruments are 
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 Boeing Model 747-200/-300 airplanes 
modified to include the Smiths Industries 5-ATI liquid crystal flight 
instruments as ADI, HSI and EDIS. These special conditions will require 
that these instruments, which 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 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 in accordance 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.

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                                                 Field strength  (volts
                                                       per meter)
                   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

[[Page 56199]]

 
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.

    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 the 
Boeing Model 747-200/-300 series airplanes modified by Hollingsead 
International, Inc. to include the Smiths Industries 5-ATI liquid 
crystal flight instruments, as ADI, HSI and EDIS. Should Hollingsead 
International apply at a later date for a supplemental type certificate 
to modify any other model included on Type Certificate No. 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 747-200/-300 series airplanes modified by 
Hollingsead 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.
    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. 
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 747-200/
-300 series airplanes modified by Hollingsead 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 October 25, 2001.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-27986 Filed 11-6-01; 8:45 am]
BILLING CODE 4910-13-P