[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