[Federal Register Volume 61, Number 41 (Thursday, February 29, 1996)]
[Rules and Regulations]
[Pages 7694-7695]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-4507]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-02-AD; Amendment 39-9526; AD 96-03-02 R1]
Airworthiness Directives; Boeing Model 767 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; correction.
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SUMMARY: This amendment clarifies information in an existing
airworthiness directive (AD), applicable to certain Boeing Model 767
series airplanes, that currently requires inspections to detect
cracking and corrosion of the aft trunnion of the outer cylinder of the
main landing gear (MLG) and various follow-on actions. That amendment
also provides for termination of the inspections by repairing the outer
cylinder and installing new aft trunnion bushings. The actions
specified in that AD are intended to prevent the collapse of the MLG
due to fracture of the aft trunnion outer cylinder. This amendment
clarifies an inspection requirement of that AD. This amendment is
prompted by communications received from affected operators that
certain of the current requirements of the AD are unclear.
DATES: Effective February 16, 1996.
The incorporation by reference of certain 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, 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, FAA, Transport Airplane Directorate, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (206) 227-2783; fax (206) 227-1181.
SUPPLEMENTARY INFORMATION: On January 22, 1996, the FAA issued AD 96-
03-02, amendment 39-9497 (61 FR 3552, February 1, 1996), which is
applicable to certain Boeing Model 767 series airplanes. That AD
requires various inspections to detect cracking and corrosion of the
aft trunnion and various follow-on actions. That AD also provides
operators with the option of terminating the requirement for the
repetitive inspections by repairing the outer cylinder, and replacing
the aft trunnion and crossbolt bushings with new bushings. That action
was prompted by a report of the collapse of the right main landing gear
(MLG) due to fracture of the aft trunnion outer cylinder. The actions
required by that AD are intended to prevent the collapse of the MLG due
to stress corrosion cracking of the aft trunnion of the outer cylinder.
Since the issuance of that AD, the FAA has received communications
from some affected operators questioning the inspection requirements of
paragraph (a) of the AD. That paragraph states that operators are to
perform the inspections described in ``Part 3 of the Accomplishment
Instructions of Boeing Alert Service Bulletin 767-32A0151, dated
November 30, 1995.'' The operators question whether ``Part 3'' is a
typographical error that should have read ``paragraph III.''
The FAA finds that clarification is necessary. Paragraph III of
Boeing Alert Service Bulletin 767-32A0151 is entitled ``Accomplishment
Instructions.'' Within paragraph III are five separate parts, entitled
``Parts 1, 2, 3, 4, and 5,'' each of which describes various inspection
procedures and follow-on actions.
The FAA's intent in AD 96-03-02 was to require that operators
perform all of the inspections (and follow-on actions) described in
Parts 1, 2, 3, 4, and 5, of paragraph III, ``Accomplishment
Instructions,'' of the referenced service bulletin. The Supplementary
Information section of the preamble to that AD correctly described all
of the inspections contained in Parts 1, 2, 3, 4, and 5, of paragraph
III of the service bulletin, as those inspections that would be
required by the AD. However, the wording of paragraph (a) of AD 96-03-
02 inadvertently was published as, ``Perform the inspections described
in Part 3 of the Accomplishment Instructions of Boeing Alert Service
Bulletin 767-32A0151 * * *'' With this wording, operators may
incorrectly interpret paragraph (a) as requiring the accomplishment of
only the inspections that are described in Part 3 of paragraph III of
the service bulletin. Such misinterpretation could result in operators
failing to perform the required inspections that are described in Parts
1, 2, 4, and 5, of paragraph III.
Since it is obvious that, currently, the requirements of AD 96-03-
02 are not clearly worded, the FAA has determined that the wording of
paragraph (a) of the AD must be revised to clarify the required
actions. This action revises paragraph (a) to state that operators must
perform all of the inspections described in paragraph III,
``Accomplishment Instructions,'' of the Boeing alert service bulletin.
Action is taken herein to clarify these requirements of AD 96-03-02
and to correctly add the AD as an amendment to section 39.13 of the
Federal Aviation Regulations (14 CFR 39.13).
The final rule is being reprinted in its entirety for the
convenience of affected operators. The effective date remains February
16, 1996.
Since this action only clarifies a current requirement, it has no
adverse economic impact and imposes no additional burden on any person.
Therefore, notice and public procedures hereon are unnecessary.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Correction
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.
[[Page 7695]]
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-9497 (61 FR
3552, February 1, 1996), and by adding a new airworthiness directive
(AD), amendment 39-9526, to read as follows:
96-03-02 R1 Boeing: Amendment 39-9526. Docket 96-NM-02-AD. Revises
AD 96-03-02, Amendment 39-9497.
Applicability: Model 767 series airplanes having line numbers
001 through 609, on which the terminating action described in
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
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, 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 that 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 the effective date of this AD. 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, 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, refers to Boeing Alert Service Bulletin 767-
32A0148, dated December 21, 1995, 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:
Perform the initial inspections within 30 days after the effective
date of this AD.
(2) For airplanes identified as Category 2 in paragraph I.C. of
Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995:
Perform the initial inspections within 90 days after the effective
date of this AD.
(3) For airplanes identified as Category 1 in paragraph I.C. of
Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995:
Perform the initial inspections prior to the accumulation of 2\1/2\
years since the MLG outer cylinder was new or overhauled, or within
150 days after the effective date of this AD, whichever occurs
later.
(b) If no cracking or corrosion is detected, accomplish the
follow-on actions described in the Boeing Alert Service Bulletin
767-32A0151, November 30, 1995, 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, 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.
(d) If any corrosion is detected, 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. The follow-on actions are to be accomplished in
accordance with that alert service bulletin.
(e) Repair of the outer cylinder and replacement of 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, constitute terminating action for the inspection
requirements of this AD, and for the requirements of AD 95-19-10,
amendment 39-9372, and AD 95-20-51, amendment 39-9398. Boeing Alert
Service Bulletin 767-32A0148, dated December 21, 1995, refers to
Component Maintenance Manual (CMM) 32-11-40. Operators should note
that, although the CMM specifies plugging the aft trunnion
lubrication fitting with a rivet, this AD does not require plugging
the lube fitting to terminate the requirement of this AD, AD 95-19-
10, or AD 95-20-51.
(f) Accomplishment of the requirements of this AD is considered
acceptable for compliance with AD 95-19-10, amendment 39-9372, and
AD 95-20-51, amendment 39-9398.
(g) 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 4: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(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, and Boeing
Alert Service Bulletin 767-32A0148, dated December 21, 1995. This
incorporation by reference 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).
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 is effective on February 16, 1996.
Issued in Renton, Washington, on February 22, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-4507 Filed 2-28-96; 8:45 am]
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