[Federal Register Volume 67, Number 46 (Friday, March 8, 2002)]
[Rules and Regulations]
[Pages 10601-10603]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-5626]



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  Federal Register / Vol. 67, No. 46 / Friday, March 8, 2002 / Rules 
and Regulations  

[[Page 10601]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM211, Special Conditions No. 25-197-SC]


Special Conditions: Boeing Model 737-300, -400, and -500 Series 
Airplanes; 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 Boeing Model 737-300, 
-400, and -500 series airplanes modified by Hollingsead International. 
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 modification 
incorporates the installation of Rockwell Collins Global Navigation 
Landing Unit (GNLU-920) Multi-Mode Receiver (MMR) system. 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 provided by the existing airworthiness standards.

DATES: The effective date of these special conditions is February 25, 
2002. Comments must be received on or before March 29, 2002.

ADDRESSES: Comments on these special conditions may be mailed in 
duplicate to: Federal Aviation Administration, Transport Airplane 
Directorate, Attn: Rules Docket (ANM-113), Docket No. NM211, 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. NM211. Comments may be inspected in 
the Rules Docket weekdays, except Federal holidays, between 7:30 a.m. 
and 4 p.m.

FOR FURTHER INFORMATION CONTACT: Gregory 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-
1320.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites interested persons to participate in this 
rulemaking by submitting written comments, data, or views. The most 
helpful comments reference a specific portion of the special 
conditions, explain the reason for any recommended change, and include 
supporting data. We ask that you send us two copies of written 
comments.
    We will file in the docket all comments we receive, as well as a 
report summarizing each substantive public contact with FAA personnel 
concerning these special conditions. The docket is available for public 
inspection before and after the comment closing date. If you wish to 
review the docket in person, go to the address in the ADDRESSES section 
of this preamble between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays.
    We will consider all comments we receive on or before the closing 
date for comments. We will consider comments filed late if it is 
possible to do so without incurring expense or delay. We may change 
these special conditions in light of the comments we receive.
    If you want the FAA to acknowledge receipt of your comments on this 
proposal, include with your comments a pre-addressed, stamped postcard 
on which the docket number appears. We will stamp the date on the 
postcard and mail it to you.

Background

    On January 8, 2002, Hollingsead International, 7416 Hollister 
Avenue, Goleta, California 93117, applied for a supplemental type 
certificate (STC) to modify Boeing Model 737-300, -400, and -500 series 
airplanes approved under Type Certificate No. A16WE. The Model 737 
series airplanes range from 101 feet, 9 inches long to 119 feet 7 
inches in length and have a wingspan of 94 feet, 9 inches. The height 
at vertical stabilizer to ground is 36 feet, 6 inches. The passenger 
load is from 140 to 188 passengers, and the range is from 2785 to 3910 
statute miles. The modification incorporates the installation of a dual 
Rockwell Collins GNLU-920 Multi-Mode Receiver (MMR) system. Each system 
consists of a Rockwell Collins GNLU-920 MMR and a Gables Engineering 
MMR Control Panel. The Rockwell Collins GNLU-920 MMR is a single 
integrated unit that enables approaches using instrument landing 
systems, microwave systems and global navigation satellite system 
functions. These functions can be susceptible to disruption to both 
command and response signals as a result of electrical and magnetic 
interference caused by high-intensity radiated fields (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 
must show that the Boeing Model 737-300, -400, and -500 series 
airplanes, as changed, continue to meet the applicable provisions of 
the regulations incorporated by reference in Type Certificate No. 
A16WE, 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 737-300, -400, and -500 series airplanes includes 14 CFR part 25, 
dated November 14, 1984, as amended by amendments 25-1 through 25-51, 
except for special conditions and exceptions noted in Type Certificate 
Data Sheet (TCDS) A16WE.
    If the Administrator finds that the applicable airworthiness 
regulations (that is, 14 CFR part 25, as amended) do not contain 
adequate or appropriate safety standards for the Boeing Model 737-300, 
-400, and -500 series airplanes because of novel or unusual design 
features, special conditions are

[[Page 10602]]

prescribed under the provisions of 14 CFR 21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the Boeing Model 737-300, -400, and -500 series airplanes 
must comply with the fuel vent and exhaust emission requirement of 14 
CFR part 34 and the noise certification requirement of part 36.
    Special conditions, as defined in 14 CFR 11.19, are issued in 
accordance with Sec. 11.38, and become part of the type certification 
basis in accordance with 14 CFR 21.101(b)(2).
    Special conditions are initially applicable to the model for which 
they are issued. Should Hollingsead International 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 features, these special conditions would also apply to 
the other model under the provisions of 14 CFR 21.101(a)(1).

Novel or Unusual Design Features

    The modified Boeing Model 737-300, -400, and -500 series airplanes 
will incorporate the Rockwell Collins GNLU-920 MMR system, which 
perform critical functions. The MMR 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. 
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 equivalent to that 
intended by the regulations incorporated by reference, special 
conditions are needed for the Boeing Model 737-300, -400 and -500 
series airplanes modified to include Rockwell Collins GNLU-920 MMR 
System. These special conditions will require that this new system, 
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 digital avionic/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 (root-mean-square) 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 field strengths 
indicated in Table 1 for the frequency ranges indicated. Both peak and 
average field strength components from Table 1 are to be demonstrated.

                                 Table 1
------------------------------------------------------------------------
                                                 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 
Boeing Model 737-300, -400 and -500 series airplanes modified by 
Hollingsead International to include the Rockwell Collins GNLU-920 MMR. 
Should Hollingsead International apply at a later date for a 
supplemental type certificate to modify any other model already 
included on Type Certificate A16WE to incorporate the same novel or 
unusual design features, these special conditions would apply to that 
model as well under the provisions of 14 CFR 21.101(a)(1).

Conclusion

    This action affects only certain design features on Boeing Model 
737-300, -400 and -500 series airplanes modified by Hollingsead 
International. 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. 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.


[[Page 10603]]


    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 Boeing Model 737-300, -
400 and -500 series airplanes modified by Hollingsead International.
    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 25, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-5626 Filed 3-7-02; 8:45 am]
BILLING CODE 4910-13-P