Document ID: FAA-2016-9301-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2016-11-22T05:00Z

[Federal Register Volume 81, Number 225 (Tuesday, November 22, 2016)]
[Proposed Rules]
[Pages 83745-83749]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-26164]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-9301; Directorate Identifier 2015-NM-193-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede Airworthiness Directive (AD) 2008-12-
04, which applies to certain Boeing Model 737-600, -700, -700C, -800, 
and -900 series airplanes. AD 2008-12-04 currently requires various 
repetitive inspections to detect cracks along the chem-milled steps of 
the fuselage skin, and to detect missing or loose fasteners in the area 
of the preventive modification or repairs, replacement of the time-
limited repair with the permanent repair if applicable, and applicable 
corrective actions, if necessary, which would end certain repetitive 
inspections. Since we issued AD 2008-12-04, an evaluation by the design 
approval holder (DAH) has indicated that the upper skin panel at the 
chem-milled step above the lap joint is subject to widespread fatigue 
damage (WFD) if the modification was installed after 30,000 total 
flight cycles. This proposed AD would reduce the post-modification 
inspection compliance times, limit installation of the preventive 
modification to airplanes with fewer than 30,000 total flight cycles, 
and add repetitive inspections for modified airplanes. We are proposing 
this AD to detect and correct cracking of the upper skin panel at the 
chem-milled step above the lap joint, which could result in reduced 
structural integrity of the airplane.

DATES: We must receive comments on this proposed AD by January 6, 2017.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, contact Boeing 
Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 
2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740; telephone 
562-797-1717; Internet https://www.myboeingfleet.com. You may view this 
referenced service information at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the 
availability of this material at the FAA, call 425-227-1221. It is also 
available on the internet at http://www.regulations.gov by searching 
for and locating Docket No. FAA-2016-9301.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-
9301; 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 proposed AD, the regulatory evaluation, any comments 
received, and other information. The street address for the Docket 
Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will 
be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Gaetano Settineri, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6577; fax: 425-917-6590; email: Gaetano.Settineri@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2016-9301; 
Directorate Identifier 2015-NM-193-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    Fatigue damage can occur locally, in small areas or structural 
design details, or in widespread areas. Multiple-site damage is 
widespread damage that occurs in a large structural element such as a 
single rivet line of a lap splice joining two large skin panels. 
Widespread damage can also occur in multiple elements such as adjacent 
frames or stringers. Multiple-site damage and multiple-element damage 
cracks are typically too small initially to be reliably detected with 
normal inspection methods. Without intervention, these cracks will 
grow, and eventually compromise the structural integrity of the 
airplane. This condition is known as widespread fatigue damage. It is 
associated with general degradation of large areas of structure with 
similar structural details and stress levels. As an airplane ages, WFD 
will likely occur, and will certainly occur if the airplane is operated 
long enough without any intervention.
    The FAA's WFD final rule (75 FR 69746, November 15, 2010) became 
effective on January 14, 2011. The WFD rule requires certain actions to 
prevent structural failure due to WFD throughout the operational life 
of certain existing transport category airplanes and all of these 
airplanes that will be certificated in the future. For existing and 
future airplanes subject to the WFD rule, the rule requires that DAHs 
establish a limit of validity (LOV) of the engineering data that 
support the structural maintenance program. Operators affected by the 
WFD rule may not fly an airplane beyond its LOV, unless an extended LOV 
is approved.
    The WFD rule (75 FR 69746, November 15, 2010) does not require 
identifying and developing maintenance actions if the DAHs can show 
that such actions are not necessary to prevent WFD before the airplane 
reaches the

[[Page 83746]]

LOV. Many LOVs, however, do depend on accomplishment of future 
maintenance actions. As stated in the WFD rule, any maintenance actions 
necessary to reach the LOV will be mandated by airworthiness directives 
through separate rulemaking actions.
    In the context of WFD, this action is necessary to enable DAHs to 
propose LOVs that allow operators the longest operational lives for 
their airplanes, and still ensure that WFD will not occur. This 
approach allows for an implementation strategy that provides 
flexibility to DAHs in determining the timing of service information 
development (with FAA approval), while providing operators with 
certainty regarding the LOV applicable to their airplanes.
    On May 29, 2008, we issued AD 2008-12-04, Amendment 39-15547 (73 FR 
32991, June 11, 2008) (``AD 2008-12-04''), for certain Boeing Model 
737-600, -700, -700C, -800, and -900 series airplanes. AD 2008-12-04 
requires various repetitive inspections to detect cracks along the 
chem-milled steps of the fuselage skin, and to detect missing or loose 
fasteners in the area of the preventive modification or repairs, 
replacement of the time-limited repair with the permanent repair if 
applicable, and applicable corrective actions, if necessary, which 
would end certain repetitive inspections. AD 2008-12-04 resulted from a 
fatigue test that revealed numerous cracks in the upper skin panel at 
the chem-milled step above the lap joint. We issued AD 2008-12-04 to 
detect and correct such fatigue-related cracks, which could result in 
the crack tips continuing to turn and grow to the point where the skin 
bay flaps open, causing decompression of the airplane.

Actions Since AD 2008-12-04 Was Issued

    Since we issued AD 2008-12-04, an evaluation by the DAH indicated 
that the upper skin panel at the chem-milled step above the lap joint 
is subject to WFD if the modification was installed after that airplane 
had accumulated 30,000 total flight cycles. We have determined that it 
is necessary to reduce the post-modification inspection compliance 
times, limit installation of the preventive modification to airplanes 
that have accumulated fewer than 30,000 total flight cycles, and add 
repetitive inspections for modified airplanes.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Service Bulletin 737-53A1232, Revision 3, 
dated July 27, 2015. This service information describes procedures for 
an external detailed inspection and an external nondestructive 
inspection (NDI) for cracks in the fuselage skin at chem-milled steps. 
Corrective actions include a permanent or time-limited repair, a 
preventive modification, and replacement of loose and missing 
fasteners. Related investigative actions include internal and external 
detailed inspections of the repair area. This service information is 
reasonably available because the interested parties have access to it 
through their normal course of business or by the means identified in 
the ADDRESSES section.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    Although this proposed AD does not explicitly restate the 
requirements of AD 2008-12-04, this proposed AD would retain all 
requirements of AD 2008-12-04. Those requirements are referenced in the 
service information identified previously, which, in turn, is 
referenced in paragraphs (g), (h), and (i) of this proposed AD. This 
proposed AD would require accomplishing the actions specified in the 
service information described previously, except as discussed under 
``Difference Between this AD and the Service Information.'' This 
proposed AD would reduce the post-modification compliance times 
required by AD 2008-12-04, limit installation of the preventive 
modification to airplanes that have not yet accumulated 30,000 total 
flight cycles, and add repetitive post-modification inspections and 
applicable corrective actions.
    The phrase ``related investigative actions'' is used in this 
proposed AD. Related investigative actions are follow-on actions that 
(1) are related to the primary action, and (2) further investigate the 
nature of any condition found. Related investigative actions in an AD 
could include, for example, inspections.
    The phrase ``corrective actions'' is used in this proposed AD. 
Corrective actions are actions that correct or address any condition 
found. Corrective actions in an AD could include, for example, repairs.

Difference Between This Proposed AD and the Service Information

    Boeing Alert Service Bulletin 737-53A1232, Revision 3, dated July 
27, 2015, specifies to contact the manufacturer for certain 
instructions, but this proposed AD would require accomplishment of 
repair methods, modification deviations, and alteration deviations in 
one of the following ways:
     In accordance with a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by the Boeing Commercial 
Airplanes Organization Designation Authorization (ODA) whom we have 
authorized to make those findings.

Costs of Compliance

    We estimate that this proposed AD affects 376 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                     Labor cost          Parts cost     Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Inspections....................  Up to 25 work-hours x                $0  Up to $2,125 per    Up to $799,000 per
                                  $85 per hour = $2,125                    inspection cycle.   inspection cycle
                                  per inspection cycle.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary repairs and 
replacements that would be required based on the results of the 
proposed inspections. We have no way of determining the number of 
aircraft that might need these replacements:

[[Page 83747]]

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                Action                            Labor cost                   Parts cost             product
----------------------------------------------------------------------------------------------------------------
Fastener replacement..................  Up to 1 work-hour x $85 per     Minimal.................             $85
                                         hour = $85.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the related investigative actions, certain repairs, 
and other applicable actions specified in this proposed 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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 the 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),
    (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.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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) 
2008-12-04, Amendment 39-15547 (73 FR 32991, June 11, 2008), and adding 
the following new AD:

The Boeing Company: Docket No. FAA-2016-9301; Directorate Identifier 
2015-NM-193-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by January 6, 
2017.

(b) Affected ADs

    This AD replaces AD 2008-12-04, Amendment 39-15547 (73 FR 32991, 
June 11, 2008) (``AD 2008-12-04'').

(c) Applicability

    This AD applies to The Boeing Company Model 737-600, -700, -
700C, -800, and -900 series airplanes, certificated in any category, 
as identified in Boeing Alert Service Bulletin 737-53A1232, Revision 
3, dated July 27, 2015.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by an evaluation by the design approval 
holder (DAH) that indicated that the upper skin panel at the chem-
milled step above the lap joint is subject to widespread fatigue 
damage (WFD) if the modification was installed after 30,000 total 
flight cycles. We are issuing this AD to detect and correct cracking 
of the upper skin panel at the chem-milled step above the lap joint, 
which could result in reduced structural integrity of the airplane.

(f) Compliance

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

(g) Inspections at Locations Without the Preventive Modification, Time-
limited Repair, or Permanent Repair Installed

    At locations where a preventive modification, time-limited 
repair, or permanent repair has not been installed as specified in 
Boeing Service Bulletin 737-53A1232: At the applicable time 
specified in paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-53A1232, Revision 3, dated July 27, 2015, do an 
external detailed inspection and an inspection specified in either 
paragraph (g)(1) or (g)(2) of this AD, for any crack in the fuselage 
skin at the chem-milled steps at specified locations, in accordance 
with Accomplishment Instructions of Boeing Alert Service Bulletin 
737-53A1232, Revision 3, dated July 27, 2015. Do all applicable 
related investigative and corrective actions before further flight 
in accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-53A1232, Revision 3, dated July 27, 2015, 
except as required by paragraph (l)(1) of this AD. Repeat the 
inspections thereafter at the applicable time specified in paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-53A1232, 
Revision 3, dated July 27, 2015.
    (1) Do an external medium frequency eddy current (MFEC), or 
magneto optic imager (MOI), or C-Scan inspection.
    (2) Do an external ultrasonic phased array (UTPA) inspection.

(h) Repetitive Post-Modification Inspections and Repair at Any Location 
With the Preventive Modification but No Time-Limited or Permanent 
Repair

    At any location with a preventive modification installed as 
specified in Boeing Alert Service Bulletin 737-53A1232: At the 
applicable time specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-53A1232, Revision 3, dated July 
27, 2015, except as required by paragraph (l)(2) of this AD, do the 
actions specified in paragraphs (h)(1) and (h)(2) of this AD.
    (1) Do external detailed and external high frequency and medium 
frequency eddy current inspections for any crack, in accordance with 
Part 7 of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-53A1232, Revision 3, dated July 27, 2015. If no crack 
is found during the inspection, repeat the inspections thereafter at 
the applicable time specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-53A1232, Revision 3, dated July 
27, 2015. If any crack is found during any inspection required by 
this paragraph, repair before further flight, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1232, Revision 3, dated July 27, 2015, except as required by 
paragraph (l)(1) of this AD.

[[Page 83748]]

    (2) Do a detailed inspection for any crack and any loose or 
missing fasteners, in accordance with Part 7 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1232, Revision 
3, dated July 27, 2015. Repeat the inspections thereafter at 
applicable time specified in paragraph 1.E, ``Compliance,'' of 
Boeing Alert Service Bulletin 737-53A1232, Revision 3, dated July 
27, 2015. If a crack is found during the inspection, or any loose or 
missing fastener is found, before further flight, do all applicable 
corrective actions, in accordance with Part V of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1232, Revision 
3, dated July 27, 2015, except as specified in paragraph (l)(1) of 
this AD.

(i) Additional Actions for Modified Airplanes

    (1) Except for preventive modifications installed on airplanes 
listed in Appendix A of Boeing Alert Service Bulletin 737-53A1232 at 
the specified total flight cycles, at any location where a 
preventive modification as specified in Boeing Alert Service 
Bulletin 737-53A1232 was installed after the accumulation of 30,000 
total flight cycles: At the applicable time specified in paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-53A1232, 
Revision 3, dated July 27, 2015, except as required by paragraph 
(l)(2) of this AD, do all applicable investigative and corrective 
actions using a method approved in accordance with the procedures 
specified in paragraph (p) of this AD.
    (2) For airplanes which have installed supplemental type 
certificate (STC) ST01697SE (http://rgl.faa.gov/
Regulatory_and_Guidance_Library/rgstc.nsf/0/
0812969a86af879b8625766400600105/$FILE/ST01697SE.pdf) and the 
preventative modification has been installed after 15,000 total 
flight cycles: Before the accumulation of 25,000 total flight 
cycles, do all applicable investigative and corrective actions using 
a method approved in accordance with the procedures specified in 
paragraph (p) of this AD.

(j) Inspections and Repair at Locations With the Permanent Chem-Milled 
Step Repair Installed

    At any location where a permanent repair has been installed as 
specified in Boeing Service Bulletin 737-53A1232: At the applicable 
time specified in paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1232, Revision 3, dated July 27, 2015: Do 
the inspections specified in paragraph (j)(1) or (j)(2) of this AD, 
in accordance with Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-53A1232, Revision 3, dated July 27, 2015. 
Repeat the inspections thereafter at the applicable time specified 
in paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1232, Revision 3, dated July 27, 2015. Do all applicable 
related investigative and corrective actions before further flight 
in accordance with Boeing Alert Service Bulletin 737-53A1232, 
Revision 3, dated July 27, 2015, except as required by paragraph 
(l)(1) of this AD.
    (1) Do an external low frequency eddy current (LFEC) inspection 
for any crack, and doubler external LFEC and external detailed 
inspections for any crack and loose or missing fasteners.
    (2) Do an external LFEC inspection for any crack, and doubler 
external LFEC and external detailed inspections for any crack and 
loose or missing fasteners; and an internal MFEC for any crack.

(k) Inspection and Replacement at Locations With a Chem-Milled Time-
Limited Repair Installed

    At any location where a chem-milled time-limited repair is 
installed, do the actions specified in paragraphs (k)(1) and (k)(2) 
of this AD, at the applicable time specified in 1.E. ``Compliance,'' 
of Boeing Alert Service Bulletin 737-53A1232, Revision 3, dated July 
27, 2015.
    (1) Do internal and external detailed inspections of the time-
limited repair for any crack, or loose or missing fasteners, in 
accordance with Part IV of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 737-53A1232, Revision 3, dated July 27, 2015. 
Repeat the inspections thereafter at the applicable time specified 
in paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1232, Revision 3, dated July 27, 2015. If any crack is found 
during the inspection, or if any loose or missing fastener is found, 
before further flight, do all applicable corrective actions, in 
accordance with Part IV of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 737-53A1232, Revision 3, dated July 27, 2015, 
except as specified in paragraph (l)(1) of this AD.
    (2) Replace the time-limited repair with the permanent repair, 
in accordance with Part IV of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1232, Revision 3, dated July 
27, 2015.

(l) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Service Bulletin 737-53A1232, Revision 3, 
dated July 27, 2015, specifies to contact Boeing for repair 
instructions, this AD requires repair before further flight using a 
method approved in accordance with the procedures specified in 
paragraph (p) of this AD.
    (2) Where paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1232, Revision 3, dated July 27, 2015, 
specifies a compliance time ``after the date of Revision 2 of this 
service bulletin,'' this AD requires compliance within the specified 
compliance time after the effective date of this AD.

(m) Optional Terminating Action

    (1) For airplanes that have accumulated 30,000 total flight 
cycles or fewer, or for airplanes on which supplemental type 
certificate (STC) ST0l697SE (http://rgl.faa.gov/
Regulatory_and_Guidance_Library/rgstc.nsf/0/
0812969a86af879b8625766400600105/$FILE/ST01697SE.pdf) was installed 
and have accumulated 15,000 total flight cycles or fewer, 
accomplishment of the preventive modification specified in Part V of 
Boeing Alert Service Bulletin 737-53A1232, Revision 3, dated July 
27, 2015, terminates the inspections required by paragraph (g) of 
this AD in the modified areas only.
    (2) Installation of a permanent repair as specified in Part III 
of Boeing Alert Service Bulletin 737-53A1232, Revision 3, dated July 
27, 2015, or a time-limited repair as specified in Part IV of Boeing 
Alert Service Bulletin 737-53A1232, Revision 3, dated July 27, 2015, 
terminates the inspections required by paragraph (g) of this AD in 
the repaired areas only.

(n) Installation Limitations of Preventive Modification

    As of the effective date of this AD, installation of the 
preventive modification specified in Boeing Alert Service Bulletin 
737-53A1232, is prohibited on the airplanes identified in paragraphs 
(n)(1) and (n)(2) of this AD.
    (1) Airplanes that have accumulated more than 30,000 total 
flight cycles.
    (2) Airplanes which have installed STC ST01697SE and that have 
accumulated more than 15,000 total flight cycles.

(o) Credit for Previous Actions

    This paragraph provides credit for the corresponding actions 
specified in paragraphs (g), (h), (i), (j), (k), and (m) of this AD, 
if those actions were performed before the effective date of this AD 
using the service information identified in paragraph (o)(1), 
(o)(2), or (o)(3) of this AD.
    (1) Boeing Special Attention Service Bulletin 737-53A1232, dated 
April 2, 2007, which was incorporated by reference in AD 2008-12-04.
    (2) Boeing Special Attention Service Bulletin 737-53A1232, 
Revision 1, dated May 18, 2012, which is not incorporated by 
reference in this AD.
    (3) Boeing Special Attention Service Bulletin 737-53A1232, 
Revision 2, dated July 26, 2013, which is not incorporated by 
reference in this AD.

(p) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (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 paragraph (q)(1) 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, modification, or alteration required by this AD 
if it is approved by the Boeing Commercial Airplanes Organization 
Designation Authorization (ODA) that has been authorized by the 
Manager, Seattle ACO, to make those findings. To be approved, the 
repair method, modification deviation, or alteration deviation must 
meet

[[Page 83749]]

the certification basis of the airplane, and the approval must 
specifically refer to this AD.
    (4) AMOCs approved previously for repairs or preventive 
modifications for AD 2008-12-04 are approved as AMOCs for the 
installation of the repair or preventive modification specified in 
this AD, provided all post-repair or post-modification inspections 
are done at the applicable times specified in the AMOC, or in tables 
1a, 1b, 2, and 3 of paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1232, Revision 3, dated July 27, 2015, 
whichever occurs first.

(q) Related Information

    (1) For more information about this AD, contact Gaetano 
Settineri, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, 
Seattle ACO, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 
425-917-6577; fax: 425-917-6590; email: Gaetano.Settineri@faa.gov.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Contractual & Data Services 
(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740; 
telephone 562-797-1717; Internet https://www.myboeingfleet.com. You 
may view this referenced service information at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For 
information on the availability of this material at the FAA, call 
425-227-1221.

    Issued in Renton, Washington, on October 25, 2016.
Dionne Palermo,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.

[FR Doc. 2016-26164 Filed 11-21-16; 8:45 am]
 BILLING CODE 4910-13-P