[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