[Federal Register Volume 59, Number 50 (Tuesday, March 15, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-5935]


[[Page Unknown]]

[Federal Register: March 15, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-218-AD]

 

Airworthiness Directives; Boeing Model 767 Series Airplanes 
Equipped With Carbon Brakes

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 series 
airplanes. This proposal would require inspections to detect cracking, 
corrosion, and wear of various components of the main landing gear 
(MLG) brake assembly, and correction of discrepancies. This proposal is 
prompted by reports indicating that components in the MLG assembly have 
been damaged due to the consequences of vibration. The actions 
specified by the proposed AD are intended to prevent failure of 
components of the MLG, which could severely affect the braking 
capability of the airplane while on the ground.

DATES: Comments must be received by May 9, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 93-NM-218-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 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: Kristin Larson, Aerospace Engineer, 
Systems & Equipment Branch, ANM-130S, FAA, Transport Airplane 
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056; telephone (206) 227-1760; fax (206) 
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 93-NM-218-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-103, Attention: Rules 
Docket No. 93-NM-218-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received several reports indicating that Boeing Model 
767 series airplanes equipped with carbon brakes have experienced 
certain vibratory conditions that have resulted in damage to or failure 
of components of the main landing gear (MLG) assembly. Such damage has 
included cracked and worn bushings on the brake load path, deformation 
of the brake rod lugs, and missing chrome or heat damage of the brake 
attach pins. Failure of these components due to the damage caused by 
the vibratory phenomenon could result in the loss of one or two brakes, 
depending upon the location of the failure. In fact, there have been 
reports of at least 14 incidents of single brake failure and 2 
incidents of two-brake failure related to these problems. This 
condition, if not corrected, could severely affect the braking 
capability of the airplane.
    The FAA has reviewed and approved Boeing Service Bulletin 767-32-
0128, dated November 11, 1993, that describes procedures for conducting 
repetitive visual, fluorescent magnetic particle, and fluorescent 
penetrant inspections to detect cracks and corrosion of the pin that 
attaches the brake rod to the brake housing, and replacement of the 
pin, if necessary. It also contains procedures for conducting visual 
inspections to detect cracking and wear of the brake torque arm 
bushing, and to detect cracking of the brake rod bushings; and repair 
or replacement of parts, if necessary. Also included are procedures for 
conducting repetitive visual inspections to detect corrosion or damage 
of the bulkhead, keeper pin, and the bore and face of the brake 
attachment pin; and replacement of parts, if necessary.
    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 repetitive inspections to detect corrosion 
and cracking of the pin that attaches the brake rod to the brake 
housing, the brake torque arm bushing, the brake rod bushings, the 
keeper pin, and the bore and face of the brake attach pin. Any 
discrepant parts would be required to be replaced or repaired, as 
applicable. The actions would be required to be accomplished in 
accordance with the service bulletin described previously.
    There are approximately 289 Model 767 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 71 
airplanes of U.S. registry would be affected by this proposed AD, that 
it would take approximately 10 work hours per airplane to accomplish 
the proposed actions, and that the average labor rate
 is $55 per work hour. Based on these figures, the total cost impact of 
the proposed AD on U.S. operators is estimated to be $39,050, or $550 
per airplane, per inspection cycle.
    The total 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. -
    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 14 
CFR part 39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES -

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

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 9.13  [Amended]

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

Boeing: Docket 93-NM-218-AD.

    Applicability: Model 767 series airplanes equipped with carbon 
brakes, certificated in any category. -
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent the failure of components of the main landing gear, 
which could severely affect the braking capability of the airplane 
while on the ground, accomplish the following: -
    (a) Within 1,500 hours time-in-service after the effective date 
of this AD, and thereafter at intervals not to exceed 1,500 hours 
time-in-service, conduct inspections to detect cracking and 
corrosion of the pin that attaches the brake rod to the brake 
housing; to detect cracking of the brake torque arm bushings; and to 
detect wear of the brake rod bushings; in accordance with Part 1 of 
Boeing Service Bulletin 767-32-0128, dated November 11, 1993. If any 
discrepancy is detected in any part, replace or repair the part in 
accordance with the compliance schedule specified in Figure 1 or 
Figure 2 of the service bulletin, as applicable.
    (b) Within 6 months after the effective date of this AD, and 
thereafter at intervals not to exceed 6 months, conduct a visual 
inspection to detect corrosion and damage of the bulkhead, the 
keeper pin, and the bore and face of the brake attach pin, in 
accordance with Part 2 of Boeing Service Bulletin 767-32-0128, dated 
November 11, 1993. If any corrosion or damage is found on any part, 
prior to further flight, replace the part in accordance with the 
service bulletin.
    (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: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (d) Special flight permits may be issued in accordance with 
Federal Aviation Regulations (FAR) 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 March 9, 1994.

Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-5935 Filed 3-14-94; 8:45 am]
BILLING CODE 4910-13-U