[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]
BILLING CODE 4910-13-P