[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
