Airworthiness Directives; Boeing Model 777 Series Airplanes

[Federal Register Volume 64, Number 161 (Friday, August 20, 1999)]
[Proposed Rules]
[Pages 45476-45477]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-21688]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-58-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 777 series 
airplanes. This proposal would require the replacement of fuse pins in 
the attachment fittings and support fittings of the main landing gear 
with new, improved fuse pins. This proposal is prompted by a report of 
corrosion of a fuse pin of a similar design on the main landing gear of 
a Boeing Model 767 series airplane. The actions specified by the 
proposed AD are intended to prevent corrosion and subsequent fracture 
of the fuse pins, which could result in collapse of the main landing 
gear and the loss of the inboard flap and outboard spoilers.

DATES: Comments must be received by October 4, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-58-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207.
    This information may be examined at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Stan Wood, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2772; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-58-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 99-NM-58-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report of corrosion of a fuse pin on the 
main landing gear of a Boeing Model 767 series airplane. Such corrosion 
could lead to fracture of the fuse pins. Fracture of the fuse pins for 
the outboard end of the main landing gear beam and upper stabilizer 
braces for the main landing gear could result in the separation of the 
main landing gear beam. This condition, if not corrected, could result 
in collapse of the main landing gear and the loss of the inboard flap 
and outboard spoilers.
    The design of the fuse pins on the Boeing Model 767 series airplane 
and those on the Model 777 series airplane is very similar. Therefore, 
the Model 777 series may be subject to the same unsafe condition 
revealed on the Model 767 series airplane.

[[Page 45477]]

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
777-57A0029, dated December 22, 1998, which describes procedures for 
the replacement of fuse pins in the attachment fittings and support 
fittings of the main landing gear with new, improved fuse pins made of 
a more corrosion resistant material. Accomplishment of the actions 
specified in the alert service bulletin is intended to adequately 
address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the alert service bulletin described previously.

Cost Impact

    There are approximately 163 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 34 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take between 5 and 
39 work hours per airplane to accomplish the proposed replacement, and 
that the average labor rate is $60 per work hour. Required parts would 
cost between $3,090 and $8,710 per airplane. Based on these figures, 
the cost impact of the proposed AD on U.S. operators is estimated to be 
between $3,390 and $11,050 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this AD were not adopted.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Boeing: Docket 99-NM-58-AD.
    Applicability: Model 777 series airplanes, as listed in Boeing 
Alert Service Bulletin 777-57A0029, dated December 22, 1998; 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent corrosion and subsequent fracture of the fuse pins in 
the main landing gear attachment and support fittings, which could 
result in collapse of the main landing gear and the loss of the 
inboard flap and outboard spoilers, accomplish the following:

Replacement

    (a) Within 48 months since date of manufacture, or 18 months 
after the effective date of this AD, whichever occurs later, replace 
the main landing gear fuse pins with new, improved fuse pins in 
accordance with Boeing Alert Service Bulletin 777-57A0029, dated 
December 22, 1998.

Spares

    (b) As of the effective date of this AD, no person shall install 
a main landing gear fuse pin having part number 112W1728-1, 
112W1728-3, or 115W1670-1 on any airplane.

Alternative Methods of Compliance

    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Seattle ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on August 16, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-21688 Filed 8-19-99; 8:45 am]
BILLING CODE 4910-13-U