[Federal Register Volume 63, Number 149 (Tuesday, August 4, 1998)]
[Proposed Rules]
[Pages 41481-41483]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20677]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-241-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 767-200, -300, and -300F
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 767-200, -
300, and -300F series airplanes. This proposal would require
replacement of the hydraulic reducer fitting in the return port of the
alternate brake selector valve with a new restrictor fitting. This
proposal is prompted by a report indicating that a brake housing had
fractured due to high loads associated with brake vibration during
landing gear retraction, which allowed the torque rod to swing free.
The actions specified by the proposed AD are intended to prevent
failure of the brake housing in the torque rod region, which could
reduce the braking capability of the airplane and/or prevent the
extension of a main landing gear by any method.
DATES: Comments must be received by September 18, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 97-NM-241-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: David Herron, Aerospace Engineer,
Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue,
SW., Renton, Washington 98055-4056; telephone (425) 227-2672; 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 97-NM-241-AD.'' The postcard will be date stamped and
returned to the commenter.
[[Page 41482]]
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. 97-NM-241-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received several reports of brake vibration during
landing gear retraction on Boeing Model 767 series airplanes, including
one report indicating that a brake housing had fractured during landing
gear retraction, allowing the torque rod to swing free. The
unrestrained torque rod caused minor damage to components located in
the wheel well. Failure of the brake housing would result in loss of
one of the eight brakes installed on a main landing gear. Furthermore,
the unrestrained torque rod could jam in the wheel well, which could
damage components located in the wheel well and/or prevent the
extension of a main landing gear. Failure of the brake housing has been
attributed to high loads associated with brake vibration during landing
gear retraction. The brake vibration is caused by excessive flow of
hydraulic fluid into the alternate system metering valves during gear
retract braking.
Excessive brake vibration could result in failure of the brake
housing in the torque rod region. This condition, if not corrected,
could reduce the braking capability of the airplane and/or prevent the
extension of a main landing gear by any method.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Service Bulletin 767-32-
0152, dated June 6, 1996; Revision 1, dated June 27, 1996; and Revision
2, dated July 10, 1997. These service bulletins describe procedures for
replacement of the hydraulic reducer fitting in the return port of the
alternate brake selector valve with a new restrictor fitting.
Accomplishment of the replacement specified in the service bulletins 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 service bulletins described previously.
Cost Impact
There are approximately 373 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 86 airplanes of U.S. registry
would be affected by this proposed AD, and that it would take
approximately 4 work hours per airplane to accomplish the proposed
replacement at an average labor rate of $60 per work hour. Required
parts would cost approximately $104 per airplane. Based on these
figures, the cost impact of the replacement proposed by this AD on U.S.
operators is estimated to be $29,584, or $344 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 97-NM-241-AD.
Applicability: Model 767-200, -300, and -300F series airplanes,
line positions 1 through 607 inclusive; equipped with carbon brakes;
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 (b) 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 brake housing in the torque rod
region, which could reduce the braking capability of the airplane
and/or prevent the extension of a main landing gear, accomplish the
following:
(a) Within 360 days after the effective date of this AD, replace
the hydraulic reducer fitting in the return port of the alternate
brake selector valve with a new restrictor fitting, in accordance
with Boeing Service Bulletin 767-32-0152, dated June 6, 1996;
Revision 1, dated June 27, 1996; or Revision 2, dated July 10, 1997.
(b) 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.
(c) 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.
[[Page 41483]]
Issued in Renton, Washington, on July 27, 1998.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-20677 Filed 8-3-98; 8:45 am]
BILLING CODE 4910-13-U
