Document ID: FAA-2012-0645-0005
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2012-09-19T04:00Z

[Federal Register Volume 77, Number 182 (Wednesday, September 19, 2012)]
[Rules and Regulations]
[Pages 57990-57994]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-22334]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0645; Directorate Identifier 2011-NM-052-AD; 
Amendment 39-17190; AD 2012-18-13]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are superseding an existing airworthiness directive (AD) 
for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and 
-500 series airplanes. That AD currently requires repetitive 
inspections to detect cracking in the web of the aft pressure bulkhead 
at body station 1016 at the aft fastener row attachment to the ``Y'' 
chord, and corrective actions if necessary. This new AD adds various 
inspections for discrepancies at the aft pressure bulkhead, and related 
investigative and corrective actions if necessary. This AD was prompted 
by several reports of fatigue cracking at that location. We are issuing 
this AD to detect and correct such fatigue cracking, which could result 
in rapid decompression of the fuselage.

DATES: This AD is effective October 24, 2012.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of October 24, 
2012.
    The Director of the Federal Register approved the incorporation by 
reference of certain other publications listed in this AD as of May 10, 
1999 (64 FR 19879, April 23, 1999).

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the referenced service 
information at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue SW., Renton, Washington. For information on the availability of 
this material at the FAA, call 425-227-1221.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (phone: 800-647-5527) is Document Management Facility, 
U.S. Department of Transportation, Docket Operations, M-30, West 
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Alan Pohl, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: (425) 917-
6450; fax: (425) 917-6590; email: alan.pohl@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to supersede AD 99-08-23, Amendment 39-11132 (64 FR 19879, 
April 23, 1999). That AD applies to the specified products. The NPRM 
published in the Federal Register on June 28, 2012 (77 FR 38547). That 
NPRM proposed to continue to require repetitive inspections to detect 
cracking in the web of the aft pressure bulkhead at body station 1016 
at the aft fastener row attachment to the ``Y'' chord, and corrective 
actions if necessary. That NPRM also proposed to require adding various 
inspections for discrepancies at the aft pressure bulkhead, and related 
investigative and corrective actions if necessary.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We have considered the comments received. Boeing supports the 
NPRM (77 FR 38547, June 28, 2012). Aviation Partners Boeing stated that 
it has reviewed the NPRM and has determined that the installation of 
winglets per supplemental type certificate ST01219SE does not affect 
the NPRM.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD as proposed.

Costs of Compliance

    We estimate that this AD affects 566 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                     Labor cost          Parts cost     Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Low frequency eddy current       8 work-hours x $85 per               $0  $680..............  $384,880.
 (LFEC) inspection [retained      hour = $680.
 actions from AD 99[dash]08-23,
 Amendment 39-11132 (64 FR
 19879, April 23, 1999)].

[[Page 57991]]

 
Detailed visual inspection       2 work-hours x $85 per                0  170...............  96,220.
 [retained actions from AD        hour = $170.
 99[dash]08[dash]23, Amendment
 39-11132 (64 FR 19879, April
 23, 1999)].
Detailed, high frequency eddy    Up to 60 work-hours x                 0  5,100 per           2,886,600 per
 current inspection, and LFEC     $85 per hour = $5,100                    inspection cycle.   inspection cycle.
 inspections of the web at the    per inspection cycle.
 ``Y'' chord of the bulkhead,
 the web located under the
 outer circumferential tear
 strap, the ``Z'' stiffeners at
 the dome cap, and existing
 repairs [new action].
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary on-condition 
inspections that would be required based on the results of the initial 
inspection. We have no way of determining the number of aircraft that 
might need these inspections:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                   Action                                 Labor cost                Parts cost        product
----------------------------------------------------------------------------------------------------------------
Detailed and HFEC inspections for oil-       1 work-hour x $85 per hour = $85...              $0             $85
 canning.
LFEC or HFEC inspections for cracking......  2 work-hours x $85 per hour = $170.               0             170
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the crack repairs specified in this AD.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD will not have a 
substantial direct effect 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.
    For the reasons discussed above, I certify that this AD:
    (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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by removing airworthiness directive (AD) 
99-08-23, Amendment 39-11132 (64 FR 19879, April 23, 1999), and adding 
the following new AD:

2012-18-13 The Boeing Company: Amendment 39-17190; Docket No. FAA-
2012-0645; Directorate Identifier 2011-NM-052-AD.

(a) Effective Date

    This airworthiness directive (AD) is effective October 24, 2012.

(b) Affected ADs

    This AD supersedes AD 99-08-23, Amendment 39-11132 (64 FR 19879, 
April 23, 1999).

(c) Applicability

    This AD applies to all The Boeing Company Model 737-100, -200, -
200C, -300, -400, and -500 series airplanes; certificated in any 
category.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by several reports of fatigue cracks in the 
aft pressure bulkhead. We are issuing this AD to detect and correct 
such fatigue cracking, which could result in rapid decompression of 
the fuselage.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Retained Initial Inspection

    This paragraph restates the initial inspection required by 
paragraph (a) of AD 99-08-23, Amendment 39-11132 (64 FR 19879, April 
23, 1999). Perform either

[[Page 57992]]

inspection specified by paragraph (g)(1) or (g)(2) of this AD at the 
time specified in paragraph (h) of this AD.
    (1) Perform a low frequency eddy current (LFEC) inspection from 
the aft side of the aft pressure bulkhead to detect discrepancies 
(including cracking, misdrilled fastener holes, and corrosion) of 
the web of the upper section of the aft pressure bulkhead at body 
station 1016 at the aft fastener row attachment to the ``Y'' chord, 
from stringer 15 left (S-15L) to stringer 15 right (S-15R), in 
accordance with Boeing 737 Nondestructive Test Manual D6-37239, Part 
6, Section 53-10-54, dated December 5, 1998.
    (2) Perform a detailed visual inspection of the aft fastener row 
attachment to the ``Y'' chord from the forward side of the aft 
pressure bulkhead to detect discrepancies (including cracking, 
misdrilled fastener holes, and corrosion) of the entire web of the 
aft pressure bulkhead at body station 1016.

(h) Retained Compliance Times

    This paragraph restates the compliance times specified in 
paragraph (b) of AD 99-08-23, Amendment 39-11132 (64 FR 19879, April 
23, 1999). Perform the inspection required by paragraph (g) of this 
AD at the time specified in paragraph (h)(1), (h)(2), or (h)(3) of 
this AD, as applicable.
    (1) For airplanes that have accumulated 40,000 or more total 
flight cycles as of May 10, 1999 (the effective date of AD 99-08-23, 
Amendment 39-11132 (64 FR 19879, April 23, 1999)): Inspect within 
375 flight cycles or 60 days after May 10, 1999 (the effective date 
of AD 99-08-23), whichever occurs later.
    (2) For airplanes that have accumulated 25,000 or more total 
flight cycles and fewer than 40,000 total flight cycles as of May 
10, 1999 (the effective date of AD 99-08-23, Amendment 39-11132 (64 
FR 19879, April 23, 1999)): Inspect within 750 flight cycles or 90 
days after May 10, 1999 (the effective date of AD 99-08-23), 
whichever occurs later.
    (3) For airplanes that have accumulated fewer than 25,000 total 
flight cycles as of May 10, 1999 (the effective date of AD 99-08-23, 
Amendment 39-11132 (64 FR 19879, April 23, 1999)): Inspect prior to 
the accumulation of 25,750 total flight cycles.

(i) Retained Repetitive Inspections

    This paragraph restates the repetitive inspections required by 
paragraph (c) of AD 99-08-23, Amendment 39-11132 (64 FR 19879, April 
23, 1999). Within 1,200 flight cycles after performing the initial 
inspection required by paragraph (g) of this AD, and thereafter at 
intervals not to exceed 1,200 flight cycles: Perform either 
inspection specified by paragraph (g)(1) or (g)(2) of this AD.

(j) Retained Corrective Actions

    This paragraph restates the corrective actions required by 
paragraph (d) of AD 99-08-23, Amendment 39-11132 (64 FR 19879, April 
23, 1999). If any discrepancy is detected during any inspection 
required by paragraph (g), (h), or (i) of this AD: Prior to further 
flight, accomplish the actions specified by paragraphs (j)(1) and 
(j)(3) of this AD, and paragraph (j)(2) of this AD, if applicable.
    (1) Perform a high frequency eddy current inspection from the 
forward side of the bulkhead to detect cracking of the web at the 
``Y'' chord attachment, around the entire periphery of the ``Y'' 
chord, in accordance with Boeing 737 Nondestructive Test Manual D6-
37239, Part 6, Section 51-00-00, Figure 23, dated November 5, 1995.
    (2) If the most recent inspection performed in accordance with 
paragraph (g) of this AD was not a detailed visual inspection: 
Accomplish the actions specified by paragraph (g)(2) of this AD. If 
the inspection was a detailed visual inspection, it is not necessary 
to repeat that inspection prior to further flight.
    (3) Repair any discrepancy such as cracking or corrosion or 
misdrilled fastener holes using a method approved in accordance with 
the procedures specified in paragraph (u) of this AD.

(k) New Requirements: Inspections of the Web at the ``Y'' Chord Upper 
Bulkhead From S-15L to S-15R

    At the later of the times specified in paragraphs (k)(1) and 
(k)(2) of this AD: Do detailed and LFEC inspections of the aft side 
of the bulkhead web, or do detailed and HFEC inspections from the 
forward side of the bulkhead, and do all applicable related 
investigative and corrective actions; in accordance with Part 1 of 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-53A1214, Revision 4, dated December 16, 2011, except as required 
by paragraphs (r)(1) and (r)(3) of this AD. Inspect for cracks, 
incorrectly drilled fastener holes, and elongated fastener holes. Do 
all applicable related investigative and corrective actions before 
further flight. Repeat the inspections at the applicable times 
specified in table 1 of paragraph 1.E., ``Compliance,'' of Boeing 
Alert Service Bulletin 737-53A1214, Revision 4, dated December 16, 
2011.
    (1) Prior to the accumulation of 25,000 total flight cycles.
    (2) Except as required by paragraphs (r)(2) and (r)(4) of this 
AD, at the later of the times specified in the ``Compliance Time'' 
column in table 1 of paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1214, Revision 4, dated December 16, 2011.

(l) New Requirements: Inspections of the Web at the ``Y'' Chord in the 
Lower Bulkhead From S-15L to S-15R

    Except as required by paragraphs (r)(2) and (r)(5) of this AD, 
at the applicable time specified in table 2 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1214, 
Revision 4, dated December 16, 2011: Do detailed and eddy current 
inspections of the web from the forward or aft side of the bulkhead 
for cracks, incorrectly drilled fasteners, and elongated fasteners, 
in accordance with Part III of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1214, Revision 4, dated 
December 16, 2011, except as required by paragraphs (r)(1) and 
(r)(3) of this AD. If any crack, incorrectly drilled fastener, 
elongated fastener, or corrosion is found, before further flight, 
repair the web using a method approved in accordance with the 
procedures specified in paragraph (u) of this AD. Repeat the 
inspections at the applicable times specified in table 2 of 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1214, Revision 4, dated December 16, 2011.

(m) New Requirements: One-Time Inspection Under the Tear Strap

    Except as required by paragraphs (r)(2) and (r)(5) of this AD, 
at the applicable time specified in table 3 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1214, 
Revision 4, dated December 16, 2011: Do a one-time LFEC inspection 
for cracks on the aft side of the bulkhead of the web located under 
the outer circumferential tear strap, or do a one-time HFEC 
inspection for cracks from the forward side of the bulkhead of the 
web located under the outer circumferential tear strap, in 
accordance with Part II of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 737-53A1214, Revision 4, dated December 16, 
2011, except as required by paragraph (r)(1) of this AD. If any 
cracking is found, before further flight, repair the bulkhead using 
a method approved in accordance with the procedures specified in 
paragraph (u) of this AD.

(n) New Requirements: Inspection for Oil-Canning

    Except as required by paragraph (r)(2) of this AD, at the 
applicable time specified in table 4 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1214, 
Revision 4, dated December 16, 2011: Do a detailed inspection from 
the aft side of the bulkhead for oil-canning and do all applicable 
related investigative and corrective actions, in accordance with 
Part II of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-53A1214, Revision 4, dated December 16, 2011, except as 
required by paragraph (r)(1) of this AD. Do all related 
investigative and corrective actions before further flight. 
Thereafter, repeat the inspection at the applicable times specified 
in table 4 of paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1214, Revision 4, dated December 16, 2011. 
For oil-cans found within the limits specified in Part II of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1214, Revision 4, dated December 16, 2011: In lieu of installing 
the repair before further flight, at the applicable times specified 
in table 4 of paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1214, Revision 4, dated December 16, 2011, 
do initial and repetitive detailed and HFEC inspections for cracks 
of the oil-canning and install the repair, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1214, Revision 4, dated December 16, 2011. If any crack is found, 
before further flight, repair the cracking using a method approved 
in accordance with the procedures specified in paragraph (u) of this 
AD. Installing the repair terminates the repetitive inspections for 
cracks.

[[Page 57993]]

(o) New Requirements: Inspection of the Dome Cap at the Center of the 
Bulkhead

    Except as required by paragraphs (r)(2) and (r)(5) of this AD, 
at the applicable time specified in table 5 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1214, 
Revision 4, dated December 16, 2011: Do an eddy current inspection 
to detect any cracking of the dome cap at the center of the 
bulkhead, and do all applicable corrective actions, in accordance 
with Part IV of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-53A1214, Revision 4, dated December 16, 2011. 
Do all corrective actions before further flight. Repeat the 
inspection at the times specified in table 5 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1214, 
Revision 4, dated December 16, 2011.

(p) New Requirements: Inspection of the Forward Flange of the ``Z'' 
Stiffeners at the Dome Cap

    Except as required by paragraphs (r)(2) and (r)(5) of this AD, 
at the applicable time specified in table 6 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1214, 
Revision 4, dated December 16, 2011: Do an HFEC inspection to detect 
any cracking of the ``Z'' stiffener flanges at the dome cap in the 
center of the bulkhead, in accordance with Part V of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1214, Revision 4, dated December 16, 2011, except as required by 
paragraph (r)(1) of this AD. If any crack is found, before further 
flight, repair the flanges using a method approved in accordance 
with the procedures specified in paragraph (u) of this AD. Repeat 
the inspection at the applicable times specified in table 6 of 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1214, Revision 4, dated December 16, 2011.

(q) New Requirements: Inspection for Existing Repairs on the Bulkhead

    Except as required by paragraph (r)(2) of this AD, at the 
applicable time specified in table 7 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1214, 
Revision 4, dated December 16, 2011: Do a detailed inspection of the 
bulkhead web and stiffeners for existing repairs, in accordance with 
Part VI of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-53A1214, Revision 4, dated December 16, 2011, except as 
required by paragraph (r)(1) of this AD.
    (1) If any repair identified in the ``Condition'' column of 
table 8 of paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-53A1214, Revision 4, dated December 16, 2011, is found 
and the ``Reference'' column refers to Appendix A, B, C, or D of 
that service bulletin: At the applicable times specified in table 8 
of paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1214, Revision 4, dated December 16, 2011, except as required 
by paragraph (r)(2) of this AD, do a HFEC inspection or a LFEC 
inspection of the web for cracking, in accordance with Appendix A, 
B, C, or D, as applicable, of Boeing Alert Service Bulletin 737-
53A1214, Revision 4, dated December 16, 2011. If any cracking is 
found, before further flight, repair using a method approved in 
accordance with the procedures specified in paragraph (u) of this 
AD. Repeat the inspections, thereafter, at the applicable intervals 
specified in table 8 of paragraph 1.E., ``Compliance,'' of Boeing 
Alert Service Bulletin 737-53A1214, Revision 4, dated December 16, 
2011.
    (2) If any repair identified in the ``Condition'' column of 
table 8 of paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-53A1214, Revision 4, dated December 16, 2011, is found 
and the ``Reference'' column refers to Appendix E of that service 
bulletin: At the applicable times specified in table 8 of paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-53A1214, 
Revision 4, dated December 16, 2011, except as required by paragraph 
(r)(2) of this AD, remove the repair and replace with a new repair, 
in accordance with Appendix E of Boeing Alert Service Bulletin 737-
53A1214, Revision 4, dated December 16, 2011.
    (3) If any non-SRM (structural repair manual) repair is found 
and the repair does not have FAA-approved damage tolerance 
inspections, except as required by paragraph (r)(2) of this AD, at 
the applicable time specified in table 7 of Paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1214, 
Revision 4, dated December 16, 2011: Contact the Boeing Commercial 
Airplanes Organization Designation Authorization (ODA) that has been 
authorized by the Manager, Seattle Aircraft Certification Office, 
for damage tolerance inspections. Do those damage tolerance 
inspections at the times given using a method approved in accordance 
with the procedures specified in paragraph (u) of this AD.

(r) Exceptions to the Service Information

    (1) Where Boeing Alert Service Bulletin 737-53A1214, Revision 4, 
dated December 16, 2011, specifies to contact Boeing for repair 
instructions: Before further flight, repair using a method approved 
in accordance with the procedures specified in paragraph (u) of this 
AD.
    (2) Where Boeing Alert Service Bulletin 737-53A1214, Revision 4, 
dated December 16, 2011, specifies a compliance time ``after the 
date of Revision 1 to this service bulletin,'' ``from the date of 
Revision 3 of this service bulletin,'' ``after the date of Revision 
3 to this service bulletin,'' or ``of the effective date of AD 99-
08-23,'' this AD requires compliance within the specified compliance 
time after the effective date of this AD.
    (3) Access and restoration procedures specified in the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1214, Revision 4, dated December 16, 2011, are not required by 
this AD. Operators may do those procedures following their 
maintenance practices.
    (4) Where table 1 of paragraph 1.E., ``Compliance'' of Boeing 
Alert Service Bulletin 737-53A1214, Revision 4, dated December 16, 
2011, specifies a compliance time relative to actions done ``in 
accordance with paragraph (a)(2) of AD 99-08-23,'' this AD requires 
compliance within the specified compliance time relative to actions 
specified in paragraph (g)(2) of this AD.
    (5) Where the Condition columns in tables 2, 3, 5, and 6 of 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1214, Revision 4, dated December 16, 2011, refer to total 
flight cycles, this AD applies to the airplanes with the specified 
total flight cycles as of the effective date of this AD.

(s) Terminating Action

    Accomplishment of the requirements of paragraphs (k) through (q) 
of this AD terminates the requirements of paragraphs (g) through (j) 
of this AD.

(t) Credit for Previous Actions

    This paragraph provides credit for the actions required by 
paragraphs (k) through (s) of this AD, if the actions were performed 
before the effective date of this AD using the service bulletins 
specified in paragraphs (t)(1) through (t)(4) of this AD.
    (1) Boeing Alert Service Bulletin 737-53A1214, dated June 17, 
1999.
    (2) Boeing Alert Service Bulletin 737-53A1214, Revision 1, dated 
June 22, 2000.
    (3) Boeing Alert Service Bulletin 737-53A1214, Revision 2, dated 
May 24, 2001.
    (4) Boeing Alert Service Bulletin 737-53A1214, Revision 3, dated 
January 19, 2011.

(u) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO, FAA, has the authority to approve 
AMOCs for this AD, if requested using the procedures found in 14 CFR 
39.19. In accordance with 14 CFR 39.19, send your request to your 
principal inspector or local Flight Standards District Office, as 
appropriate. If sending information directly to the manager of the 
ACO, send it to the attention of the person identified in the 
Related Information section of this AD. Information may be emailed 
to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD if it is approved by the 
Boeing Commercial Airplanes ODA that has been authorized by the 
Manager, Seattle ACO to make those findings. For a repair method to 
be approved, the repair must meet the certification basis of the 
airplane, and the approval must specifically refer to this AD.
    (4) AMOCs approved previously in accordance with AD 99-08-23, 
Amendment 39-11132 (64 FR 19879, April 23, 1999), are approved as 
AMOCs for the corresponding provisions of this AD.

(v) Related Information

    For more information about this AD, contact Alan Pohl, Aerospace 
Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, Washington 
98057-3356; phone: (425) 917-6440; fax: (425) 917-6590; email: 
alan.pohl@faa.gov.

[[Page 57994]]

(w) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (3) The following service information was approved for IBR on 
October 24, 2012.
    (i) Boeing Alert Service Bulletin 737-53A1214, Revision 4, dated 
December 16, 2011.
    (ii) Reserved.
    (4) The following service information was approved for IBR on 
May 10, 1999 (64 FR 19879, April 23, 1999).
    (i) Boeing 737 Nondestructive Test Manual D6-37239, Part 6, 
Section 53-10-54, dated December 5, 1998.
    (ii) Boeing 737 Nondestructive Test Manual D6-37239, Part 6, 
Section 51-00-00, Figure 23, dated November 5, 1995.
    (5) For The Boeing Company service information identified in 
this AD, contact Boeing Commercial Airplanes, Attention: Data & 
Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 
98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; 
Internet https://www.myboeingfleet.com.
    (6) You may review copies of the referenced service information 
at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., 
Renton, Washington. For information on the availability of this 
material at the FAA, call 425-227-1221.
    (7) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on August 31, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-22334 Filed 9-18-12; 8:45 am]
BILLING CODE 4910-13-P