Airworthiness Directives; Boeing 777-200 Series Airplanes

[Federal Register Volume 64, Number 161 (Friday, August 20, 1999)]
[Proposed Rules]
[Pages 45472-45474]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-21690]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-03-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing 777-200 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to revise an existing airworthiness 
directive (AD), applicable to certain Boeing 777-200 series airplanes, 
that currently requires repetitive visual inspections to determine the 
presence and condition of the nut and cotter pin of the lock link 
mechanism on the side struts and drag struts on the main landing gear 
(MLG); and corrective action, if necessary. That AD was prompted by 
reports of missing or damaged components on the lock link mechanism. 
The actions specified by that AD are intended to prevent failure of the 
lock link mechanism to lock the MLG in the down position, and 
consequent collapse of the MLG during ground operation. This action 
would provide for an optional terminating action for the repetitive 
inspections.

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-03-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00

[[Page 45473]]

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, 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-03-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-03-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On January 15, 1998, the FAA issued AD 98-02-06, amendment 39-10288 
(63 FR 3458, January 23, 1998), applicable to certain Boeing 777-200 
series airplanes, to require repetitive visual inspections to determine 
the presence and condition of the nut and cotter pin of the lock link 
mechanism on the side struts and drag struts on the main landing gear 
(MLG); and corrective action, if necessary. That action was prompted by 
reports of missing or damaged components on the lock link mechanism. 
The requirements of that AD are intended to prevent failure of the lock 
link mechanism to lock the MLG in the down position, and consequent 
collapse of the MLG during ground operation.

Actions Since Issuance of Previous Rule

    Since the issuance of that AD, the FAA has reviewed and approved 
Boeing Service Bulletin 777-32-0016, dated January 14, 1999. The 
service bulletin describes procedures for replacement of the existing 
retention bolt, end caps, washer, and nut of the lock link mechanism on 
the side struts and drag struts on the MLG with a new lock link 
assembly that incorporates a new bolt, washer, nut, and end-caps. 
Accomplishment of this action would eliminate the need for the 
repetitive inspections required by AD 98-02-06 and would positively 
address the unsafe condition addressed by that AD.

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 revise AD 98-02-06 to continue to require repetitive 
visual inspections to determine the presence and condition of the nut 
and cotter pin of the lock link mechanism on the side struts and drag 
struts on the MLG; and corrective action, if necessary. This proposed 
AD also would provide for an optional terminating action for the 
repetitive inspections. The optional terminating action, if 
accomplished, would be required to be accomplished in accordance with 
the service bulletin described previously.
    The FAA is not proposing to mandate the replacement of the existing 
retention bolt of the lock link mechanism on the side struts and drag 
struts on the MLG for several reasons:
    1. Accessing the lock link mechanism area on the MLG for inspection 
is easily accomplished.
    2. The failed retention system of the bolt is easily detectable by 
means of a visual inspection.
    3. The loss of a bolt may adversely affect the MLG during ground 
operations; however, the visual inspections will preclude the failure 
of the bolt retention system, which could result in collapse of the MLG 
during ground operations.

Cost Impact

    There are approximately 40 Model 777-200 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 17 
airplanes of U.S. registry would be affected by this proposed AD.
    The inspection that is currently required by AD 98-02-06, and 
retained in this AD, takes approximately 2 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $2,040, or $120 per airplane, per inspection cycle.
    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.
    Should an operator elect to accomplish the optional terminating 
action rather than continue the repetitive inspections, it would take 
approximately 1 work hour per airplane to accomplish the replacement, 
at an average labor rate of $60 per work hour. Required parts would 
cost approximately $5,094 per airplane. Based on these figures, the 
cost impact of this optional terminating action is estimated to be 
$5,154 per airplane.

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

[[Page 45474]]

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 removing amendment 39-10288 (63 FR 
3458, January 23, 1998), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 99-NM-03-AD. Revises AD 98-02-06, amendment 39-10288.

    Applicability: Model 777-200 series airplanes, line positions 1 
through 40 inclusive, 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 failure of the lock link mechanism to lock the main 
landing gear (MLG) in the down position, and consequent collapse of 
the MLG during ground operation, accomplish the following:

Restatement of the Requirements of AD 98-02-06

Repetitive Inspections and Corrective Actions

    (a) Within 30 days after February 9, 1998 (the effective date of 
AD 98-02-06, amendment 39-10288), perform a visual inspection to 
determine the presence and condition of the cotter pin and nut of 
the lock link mechanism on the side struts and drag struts on the 
left- and right-hand MLG, in accordance with Boeing Alert Service 
Bulletin 777-32A0015, dated September 4, 1997. If any discrepancy is 
found, prior to further flight, correct the discrepancy in 
accordance with the service bulletin. Repeat the inspection 
thereafter at intervals not to exceed 75 days or 400 flight cycles, 
whichever occurs first.

New Actions Proposed by This AD

Optional Terminating Action

    (b) Replacement of the existing retention bolt, end caps, 
washer, and nut of the lock link mechanism on the side struts and 
drag struts on the MLG with a new lock link assembly that 
incorporates a new bolt, washer, nut, and end-caps, in accordance 
with Boeing Service Bulletin 777-32-0016, dated January 14, 1999, 
constitutes terminating action for the requirements of this AD.

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 
Secs. 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. 99-21690 Filed 8-19-99; 8:45 am]
BILLING CODE 4910-13-U