[Federal Register Volume 61, Number 207 (Thursday, October 24, 1996)]
[Rules and Regulations]
[Pages 55080-55082]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-26722]
[[Page 55080]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-25-AD; Amendment 39-9783; AD 96-21-06]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 767 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to certain Boeing 767 series airplanes, that currently
requires inspections and various follow-on actions to detect cracking
and corrosion of the aft trunnion of the outer cylinder of the main
landing gear (MLG). That action also provides for the optional
termination of the inspections by repairing the outer cylinder and
installing new aft trunnion bushings. That AD was prompted by reports
of failure of several MLG due to fracture of the aft trunnion outer
cylinder. This amendment requires operators to implement the previously
optional terminating action. The actions specified by this AD are
intended to prevent the collapse of the MLG due to stress corrosion
cracking of the aft trunnion of the outer cylinder.
DATES: Effective November 29, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of November 29, 1996.
The incorporation by reference of certain other publications listed
in the regulations was approved previously by the Director of the
Federal Register as of February 16, 1996 (61 FR 3552, February 1,
1996).
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the Federal
Aviation Administration (FAA), Transport Airplane Directorate, Rules
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of
the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
FOR FURTHER INFORMATION CONTACT: James G. Rehrl, Aerospace Engineer,
Airframe Branch, ANM-120S, Seattle Aircraft Certification Office, FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (206) 227-2783; fax (206) 227-1181.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 96-03-02 R1,
amendment 39-9526 (61 FR 7694, February 29, 1996), which is applicable
to certain Boeing Model 767 series airplanes, was published in the
Federal Register on May 14, 1996 (61 FR 24250). The action proposed to
supersede AD 96-03-02 R1 to continue to require various inspections and
various follow-on actions to detect cracking and corrosion of the aft
trunnion of the outer cylinder of the MLG. The action also proposed to
require repair of the outer cylinder and replacement of the bushings in
the aft trunnion and crossbolt of the MLG with new bushings.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Support for the Proposed Rule
Two commenters support the proposal.
Request to Limit the Applicability of the AD
One commenter, the manufacturer, requests that the applicability of
the AD be revised to reflect line numbers 1 through 605, instead of
line numbers 1 through 609. The manufacturer states that line numbers
606 through 609 were reworked on the production line to incorporate the
terminating action specified by the proposed AD.
The FAA concurs, and the applicability of the final rule has been
revised accordingly.
Request to Refer to the Revised CMM
The manufacturer states that the current wording of the proposed
rule indicates that the Component Maintenance Manual (CMM) contains
only one acceptable configuration for certain associated procedures;
specifically, that of plugging the aft trunnion lubrication fitting.
The manufacturer states that the CMM has been revised since the
issuance of the proposed rule and now includes another acceptable
configuration. The alternative configuration entails not plugging the
aft trunnion lubrication fitting. The manufacturer, therefore, requests
that the proposed rule be revised to reflect the inclusion of both
configurations in the CMM.
The FAA concurs. The FAA considers that either of the two
configurations specified by the CMM is an acceptable configuration, and
has revised NOTE 4 of the final rule, accordingly.
Request to Delete 5 and \1/2\ year Compliance Time for Category 3
Airplanes
One commenter notes that the compliance time for repair/replacement
for Category 3 airplanes, as specified in paragraph (e)(1) of the
proposed rule, indicates that those actions are to be accomplished
``prior to the accumulation of 5 and \1/2\ years since the MLG outer
cylinders were new or last overhauled, or within 18 months after the
effective date of the AD.'' However, the commenter points out that,
since the age of the outer cylinders are determined from the date of
February 16, 1996, there will never be a situation in which a Category
3 cylinder will reach 5 and \1/2\ years of age within 18 months from
the effective date of the final rule. Therefore, the commenter requests
that reference to the 5 and \1/2\-year compliance time be deleted.
The FAA concurs, and has revised paragraph (e)(1) of the final rule
accordingly.
Request to Add Requirements for Follow-on Actions
One commenter notes that the compliance time for repetitive
inspections specified in paragraph (a) of the proposal requires
inspections at intervals specified in Boeing Alert Service Bulletin
767-32A0151, dated November 30, 1995. The commenter states that the
proposed compliance time (of within 18 months after the effective date
of the AD) for the terminating action required by paragraph (e) of this
AD would permit a period of time (approximately 5 to 6 months) in which
Category 3 airplanes would not be required to perform any inspections.
Therefore, the commenter requests that the proposed rule be revised to
require certain follow-on actions until the terminating action required
by paragraph (e) of the proposed rule is accomplished.
The FAA does not concur. Two other AD's [namely, AD 95-19-10,
amendment 39-9372 (60 FR 47689, September 14, 1995); and AD 95-20-51,
amendment 39-9398 (60 FR 53109, October 12, 1995)] currently exist that
require similar inspections to detect cracking and corrosion and
certain other follow-on actions of the aft trunnion of the outer
cylinder of the MLG. The FAA has determined that the subject unsafe
condition will be positively addressed by those actions in the interim
until the terminating action of this AD is accomplished. Therefore, the
FAA finds
[[Page 55081]]
that it is unnecessary to add additional inspection requirements in
this AD.
Request to Reference Later Revisions of Cited Service Bulletins
The manufacturer stated that it has revised Boeing Service Bulletin
767-32A0151 and Boeing Service Bulletin 767-32A0148 to provide further
clarification of the inspection and modification procedures. Therefore,
the manufacturer requests that the FAA refer to these later revisions
as being acceptable methods of compliance with the AD.
The FAA concurs. The FAA has reviewed and approved Revision 1 of
both service bulletins, each dated October 10, 1996, and has revised
the AD to cite these revisions as an additional source of service
information.
Request to Correct Referenced AD Number
One commenter requests that the reference to ``AD 93-03-02 R1'' in
paragraph (h)(2) of the proposed rule be corrected to read ``AD 96-03-
02 R1.'' The FAA has noted this typographical error and has revised
paragraph (h)(2) of the final rule accordingly.
Conclusion
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the changes previously
described. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Cost Impact
There are approximately 605 Boeing Model 767 series airplanes of
the affected design in the worldwide fleet. The FAA estimates that 200
airplanes of U.S. registry will be affected by this proposed AD.
The actions that are currently required by AD 96-03-02 R1, and
retained in this AD, take approximately 34 work hours per airplane to
accomplish, at an average labor rate of $60 per work hour. Based on
these figures, the cost impact on U.S. operators of the actions
currently required is estimated to be $408,000, or $2,040 per airplane.
The new actions that are required by this AD action will take
approximately 218 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Required parts will cost approximately
$9,510 per airplane. Based on these figures, the cost impact on U.S.
operators of the requirements of this AD is estimated to be $4,518,000
or $22,590 per airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the requirements of this
AD action, and that no operator would accomplish those actions in the
future if this AD was not adopted.
Regulatory Impact
The regulations adopted herein will 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 final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it may be obtained
from the Rules Docket at the location provided under the caption
ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends 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 removing amendment 39-9526 (61 FR
7694, February 29, 1996), and by adding a new airworthiness directive
(AD), amendment 39-9783, to read as follows:
96-21-06 Boeing: Amendment 39-9783. Docket 96-NM-25-AD. Supersedes
AD 96-03-02 R1, Amendment 39-9526.
Applicability: Model 767 series airplanes having line numbers
001 through 605 inclusive, on which the terminating action required
by paragraph (e) of this AD has not been accomplished; 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 (g) 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 the collapse of the main landing gear (MLG) due to
stress corrosion cracking of the aft trunnion of the outer cylinder,
accomplish the following:
(a) Perform the inspections described in paragraph III,
Accomplishment Instructions, of Boeing Alert Service Bulletin 767-
32A0151, dated November 30, 1995, or Revision 1, dated October 10,
1996, to detect cracking and corrosion of the aft trunnion of the
outer cylinder of the MLG at the time specified in paragraph (a)(1),
(a)(2), or (a)(3) of this AD, as applicable. These inspections are
to be accomplished in accordance with Figure 1 of the alert service
bulletin. Repeat these inspections thereafter at the intervals
specified in that alert service bulletin. To determine the category
in which an airplane falls, the age of the outer cylinder of the MLG
is to be calculated as of February 16, 1996, (the effective date of
AD 96-03-02 R1, amendment 39-9526). For airplanes on which the age
of the right MLG differs from the age of the left MLG, an operator
may place the airplane into a category that is the higher
(numerically) of the two categories to ease its administrative
burden, and to simplify the recordkeeping requirements imposed by
this AD. Once the category into which an airplane falls is
determined, operators must obtain approval from the Manager, Seattle
Aircraft Certification Office (ACO), FAA, Transport Airplane
Directorate, to move that airplane into another category.
Note 2: The broken (dash) lines used in Figure 1 of Boeing Alert
Service Bulletin 767-32A0151, dated November 30, 1995, and Revision
1, dated October 10, 1996, denote ``go to'' actions for findings of
discrepancies detected during any of the inspections required by
this AD.
Note 3: Boeing Alert Service Bulletin 767-32A0151, dated
November 30, 1995, and Revision 1, dated October 10, 1996, refer to
[[Page 55082]]
Boeing Alert Service Bulletin 767-32A0148, dated December 21, 1995,
and Revision 1, dated October 10, 1996, for procedures to repair the
outer cylinder and replace the bushings in the outer cylinder of the
MLG with new bushings.
(1) For airplanes identified as Category 3 in paragraph I.C. of
Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995,
or Revision 1, dated October 10, 1996: Perform the initial
inspections within 30 days after February 16, 1996 (the effective
date of AD 96-03-02 R1, amendment 39-9526).
(2) For airplanes identified as Category 2 in paragraph I.C. of
Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995,
or Revision 1, dated October 10, 1996: Perform the initial
inspections within 90 days after February 16, 1996.
(3) For airplanes identified as Category 1 in paragraph I.C. of
Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995,
or Revision 1, dated October 10, 1996: Perform the initial
inspections prior to the accumulation of 2-\1/2\ years since the MLG
outer cylinder was new or last overhauled, or within 150 days after
February 16, 1996, whichever occurs later.
(b) If no cracking or corrosion is detected during the
inspections required by paragraph (a) of this AD, accomplish the
follow-on actions described in the Boeing Alert Service Bulletin
767-32A0151, November 30, 1995, or Revision 1, dated October 10,
1996, at the time specified in the alert service bulletin. These
follow-on actions are to be accomplished in accordance with that
alert service bulletin.
(c) If any cracking is detected during the inspections required
by paragraph (a) of this AD, prior to further flight, replace the
outer cylinder with a new or serviceable outer cylinder in
accordance with Boeing Alert Service Bulletin 767-32A0151, dated
November 30, 1995, or Revision 1, dated October 10, 1996.
(d) If any corrosion is detected during the inspections required
by paragraph (a) of this AD, accomplish the follow-on actions at the
time specified in the ``Corrosion Flowchart,'' in Figure 1 of Boeing
Alert Service Bulletin 767-32A0151, dated November 30, 1995, or
Revision 1, dated October 10, 1996. The follow-on actions are to be
accomplished in accordance with that alert service bulletin.
(e) At the time specified in either paragraph (e)(1) or (e)(2),
as applicable, repair the outer cylinder and replace the bushings in
the aft trunnion and crossbolt of the MLG with new bushings, in
accordance with Boeing Alert Service Bulletin 767-32A0148, dated
December 21, 1995, or Revision 1, dated October 10, 1996.
Accomplishment of this repair and replacement constitutes
terminating action for this AD, and for the requirements of AD 95-
19-10, amendment 39-9372; and AD 95-20-51, amendment 39-9398.
Note 4: Boeing Alert Service Bulletin 767-32A0148 refers to
Component Maintenance Manual (CMM) 32-11-40 for certain procedures.
Operators should note that this AD does not require that one or the
other of the two configurations/actions be accomplished in order to
terminate the requirements of this AD, AD 95-19-10, or AD 95-20-51.
The use of either configuration specified in the CMM is considered
to be the operator's prerogative.
(1) For airplanes identified as Category 3 in paragraph I.C. of
Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995,
or Revision 1, dated October 10, 1996: Accomplish the repair and
replacement within 18 months after the effective date of this AD.
(2) For airplanes identified as either Category 1 or Category 2
in paragraph I.C. of Boeing Alert Service Bulletin 767-32A0151,
dated November 30, 1995, or Revision 1, dated October 10, 1996:
Accomplish the repair and replacement at the time specified in
either paragraph (e)(2)(i) or (e)(2)(ii) of this AD:
(i) Prior to the accumulation of 5-and-\1/2\ years since the MLG
outer cylinders were new or last overhauled, or within 18 months
after the effective date of this AD, whichever occurs later. Or,
(ii) Prior to the accumulation of 7 years since the MLG outer
cylinders were new or last overhauled, provided that accomplishment
of visual and non-destructive testing (NDT) inspections at the times
specified in Figure 1 of the Accomplishment Instructions of Boeing
Alert Service Bulletin 767-32A0151, dated November 30, 1995, or
Revision 1, dated October 10, 1996, are repeated until the repair
and replacement are accomplished.
(f) Accomplishment of the inspection requirements of this AD (in
accordance with Boeing Alert Service Bulletin 767-32A0151, dated
November 30, 1995, or Revision 1, dated October 10, 1996) is
considered acceptable for compliance with AD 95-19-10, amendment 39-
9372; and AD 95-20-51, amendment 39-9398.
(g)(1) 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 ACO. 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 5: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(2) Alternative methods of compliance, approved in accordance
with AD 96-03-02, amendment 39-9497; AD 96-03-02 R1, amendment 39-
9526; AD 95-19-10, amendment 39-9372; or AD 95-20-51, amendment 39-
9398; are approved as alternative methods of compliance with this
AD.
(h) 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.
(i) The actions shall be done in accordance with Boeing Alert
Service Bulletin 767-32A0151, dated November 30, 1995; Boeing
Service Bulletin 767-32A0151, Revision 1, dated October 10, 1996;
Boeing Alert Service Bulletin 767-32A0148, dated December 21, 1995,
and Boeing Service Bulletin 767-32A0148, Revision 1, dated October
10, 1996. The incorporation by reference of Boeing Alert Service
Bulletin 767-32A0151, dated November 30, 1995, and Boeing Alert
Service Bulletin 767-320148, dated December 21, 1995, was approved
previously by the Director of the Federal Register, in accordance
with 5 U.S.C. 552(a) and 1 CFR part 51, as of February 16, 1996 (61
FR 3552, February 1, 1996). The incorporation by reference of Boeing
Service Bulletin 767-32A0151, Revision 1, dated October 10, 1996,
and Boeing Service Bulletin 767-32A0148, Revision 1, dated October
10, 1996, was approved by the Director of the Federal Register in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be
obtained from Boeing Commercial Airplane Group, P.O. Box 3707,
Seattle, Washington 98124-2207. Copies may be inspected at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington; or at the Office of the Federal Register, 800 North
Capitol Street, NW., suite 700, Washington, DC.
(j) This amendment becomes effective on November 29, 1996.
Issued in Renton, Washington, on October 10, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-26722 Filed 10-23-96; 8:45 am]
BILLING CODE 4910-13-U
