[Federal Register Volume 62, Number 140 (Tuesday, July 22, 1997)]
[Proposed Rules]
[Pages 39195-39197]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-19176]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-52-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 767 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 series
airplanes. This proposal would require repetitive inspections to detect
corrosion or plating cracks of the pin assemblies in the forward
trunnion support of the main landing gear (MLG), and replacement of the
pin assembly with a new assembly, if necessary. Such replacement, if
accomplished, would constitute terminating action for the repetitive
inspections. This proposal is prompted by reports indicating that these
pin assemblies were found to have corroded as a result of plating
cracks. The actions specified by the proposed AD are intended to detect
and correct such corrosion and plating cracks, which could cause
breakage of these assemblies, and consequent collapse of the MLG.
DATES: Comments must be received by September 2, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-52-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: James G. Rehrl, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington; telephone (425) 227-2783;
fax (425) 227-1181.
[[Page 39196]]
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-52-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. 97-NM-52-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received several reports of corrosion on pin assemblies
in the forward trunnion support of the main landing gear (MLG)
installed on Boeing Model 767 series airplanes. At the time these
corroded pin assemblies were found, the airplanes had accumulated
between 6,900 and 12,600 total landings.
The manufacturer performed a review of several pin assemblies and
determined that the bond between the 4330M Steel pin and its Class 2
chrome plating is not sufficient to prevent the plating from cracking
and peeling. Such cracking and peeling provide sites for moisture to
corrode the pin. Corrosion of these pin assemblies, if not detected and
corrected in a timely manner, could cause breakage of the pin
assemblies, and consequent collapse of the MLG.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
767-57A0047, Revision 1, dated May 9, 1996, which describes procedures
for repetitive close visual inspections to detect corrosion or plating
cracks of the 4330M Steel pin assemblies in the forward trunnion
support of the MLG, and replacement of the pin assembly with a new
asembly, if necessary. Replacement of pin assemblies with new ones made
from a different material and finish would eliminate the need for
further inspections of those assemblies. The new assemblies are made
from 15-5PH CRES with Class 3 chrome plating, and are more resistant to
corrosion and plating cracks.
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 repetitive close visual inspections to detect
corrosion or plating cracks of the 4330M Steel pin assemblies in the
forward trunnion support of the MLG, and replacement of the pin
assembly with a new assembly, if necessary. Such replacement would
constitute terminating action for the repetitive inspections.
The actions would be required to be accomplished in accordance with
the service bulletin described previously.
Cost Impact
There are approximately 562 Boeing Model 767 series airplanes of
the affected design in the worldwide fleet. The FAA estimates that 151
airplanes of U.S. registry would be affected by this proposed AD, that
it would take approximately 65 work hours per airplane to accomplish
the proposed inspection, and that the average labor rate is $60 per
work hour. Based on these figures, the cost impact of the proposed AD
on U.S. operators is estimated to be $588,900, or $3,900 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.
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-52-AD.
Applicability: Model 767 series airplanes having line positions
1 through 562 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
otherwise 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 (e) 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.
[[Page 39197]]
Compliance: Required as indicated, unless accomplished
previously.
To detect and correct corrosion or plating cracks of the pin
assemblies in the front trunnion support of the main landing gear
(MLG), which could cause these assemblies to break and result in
collapse of the MLG, accomplish the following:
(a) Perform a close visual inspection to detect corrosion or
plating cracks of each 4330M Steel pin assembly in the forward
trunnion support of the MLG, in accordance with Boeing Alert Service
Bulletin 767-57A0047, Revision 1, dated May 9, 1996, at the later of
the times specified in paragraphs (a)(1) and (a)(2) of this AD.
(1) Within 4 years since date of manufacture of the airplane, or
4 years since the last overhaul of the MLG. Or
(2) Within 18 months after the effective date of this AD.
(b) If no corrosion or crack is detected, repeat the close
visual inspection thereafter at intervals not to exceed 48 months.
(c) If any corrosion or crack is detected, prior to further
flight, replace it with a new pin assembly made from 15-5PH CRES
with Class 3 chrome plating, in accordance with Boeing Alert Service
Bulletin 767-57A0047, Revision 1, dated May 9, 1996.
(d) Accomplishment of replacement of a 4330M Steel pin assembly
with a new pin assembly made from 15-5PH CRES with Class 3 chrome
plating, in accordance with Boeing Alert Service Bulletin 767-
57A0047, Revision 1, dated May 9, 1996, constitutes terminating
action for the inspections required by this AD for that pin
location.
Note 2: Replacement of a 4330M Steel pin assembly with a new pin
assembly made from 15-5PH CRES with Class 3 chrome plating prior to
the effective date of this AD, in accordance with Boeing Service
Bulletin 767-57A0047, dated January 19, 1995, is considered an
acceptable method of compliance with paragraph (d) of this AD for
that pin location.
(e) 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 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(f) 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.
Issued in Renton, Washington, on July 16, 1997.
Gary L. Killion,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-19176 Filed 7-21-97; 8:45 am]
BILLING CODE 4910-13-P
