81 FR 34871 - Airworthiness Directives; The Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 81, Issue 105 (June 1, 2016)

We are superseding Airworthiness Directive (AD) 2011-23-05 for all The Boeing Company Model 737-300, -400, and -500 series airplanes. AD 2011-23-05 required repetitive inspections for cracking of the 1.04- inch nominal diameter wire penetration hole, and applicable related investigative and corrective actions. This new AD adds new inspection areas, a modification that terminates certain inspections, post- modification inspections, and repair if necessary. This AD was prompted by an evaluation by the design approval holder (DAH) that indicates the fuselage frames and frame reinforcements are subject to widespread fatigue damage (WFD). We are issuing this AD to detect and correct fatigue cracking of the fuselage frames and frame reinforcements that could result in reduced structural integrity of the airplane.

[Federal Register Volume 81, Number 105 (Wednesday, June 1, 2016)]
[Rules and Regulations]
[Pages 34871-34876]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2016-12329]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-5812; Directorate Identifier 2015-NM-077-AD; 
Amendment 39-18531; AD 2016-11-04]
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 Airworthiness Directive (AD) 2011-23-05 for 
all The Boeing Company Model 737-300, -400, and -500 series airplanes. 
AD 2011-23-05 required repetitive inspections for cracking of the 1.04-
inch nominal diameter wire penetration hole, and applicable related 
investigative and corrective actions. This new AD adds new inspection 
areas, a modification that terminates certain inspections, post-
modification inspections, and repair if necessary. This AD was prompted 
by an evaluation by the design approval holder (DAH) that indicates the 
fuselage frames and frame reinforcements are subject to widespread 
fatigue damage (WFD). We are issuing this AD to detect and correct 
fatigue cracking of the fuselage frames and frame reinforcements that 
could

[[Page 34872]]

result in reduced structural integrity of the airplane.

DATES: This AD is effective July 6, 2016.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of July 6, 
2016.
    The Director of the Federal Register approved the incorporation by 
reference of a certain other publication listed in this AD as of 
November 16, 2011 (76 FR 67343, November 1, 2011).

ADDRESSES: For service information identified in this final rule, 
contact Boeing Commercial Airplanes, Attention: Data & Services 
Management, P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 
206-544-5000, extension 1; fax 206-766-5680; 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-2015-
5812.

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-2015-
5812; 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 Docket 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: Galib Abumeri, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office (ACO), 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 
562-627-5324; fax: 562-627-5210; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to supersede AD 2011-23-05, Amendment 39-16856 (76 FR 67343, 
November 1, 2011) (``AD 2011-23-05''). AD 2011-23-05 applied to certain 
Model 737-300, -400, and -500 series airplanes. The NPRM published in 
the Federal Register on November 27, 2015 (80 FR 74047) (``the NPRM''). 
The NPRM was prompted by an evaluation by the DAH that indicates the 
fuselage frames and frame reinforcements are subject to WFD. The NPRM 
proposed to continue to require repetitive inspections for cracking of 
the 1.04-inch nominal diameter wire penetration hole, and applicable 
related investigative and corrective actions. The NPRM also proposed to 
add new inspection areas, a modification that terminates certain 
inspections, post-modification inspections, and repair if necessary. We 
are issuing this AD to detect and correct fatigue cracking of the 
fuselage frames and frame reinforcements that could result in reduced 
structural integrity of the airplane.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the NPRM and 
the FAA's response to each comment.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that accomplishing the supplemental 
type certificate (STC) ST01219SE (http://rgl.faa.gov/
Regulatory_and_Guidance_Library/rgstc.nsf/0/
ebd1cec7b301293e86257cb30045557a/$FILE/ST01219SE.pdf) does not affect 
the actions specified in the NPRM.
    We agree with the commenter. We have redesignated paragraph (c) of 
the proposed AD as paragraph (c)(1) and added a new paragraph (c)(2) to 
this AD to state that installation of STC ST01219SE (http://
rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/
ebd1cec7b301293e86257cb30045557a/$FILE/ST01219SE.pdf) does not affect 
the ability to accomplish the actions required by this AD. Therefore, 
for airplanes on which STC ST01219SE is installed, a ``change in 
product'' alternative method of compliance (AMOC) approval request is 
not necessary to comply with the requirements of 14 CFR 39.17.

Request To Revise Applicability

    Boeing requested that we change the applicability to ``all'' 
airplanes instead of airplanes referenced in Boeing Alert Service 
Bulletin 737-53A1279, Revision 2, dated April 21, 2015. Boeing stated 
that Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated April 
21, 2015, specifies the effectivity as ``all'' airplanes.
    We agree with the commenter's request. In the NPRM we referred to 
Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated April 21, 
2015, which specifies an effectivity of all Model 737-300, -400, and -
500 series airplanes. For clarity, we have revised the SUMMARY section 
and paragraph (c)(1) of this AD to specify ``all'' airplanes.

Request To Revise Compliance Time

    Southwest Airlines (SWA) requested that we revise paragraph (t) of 
the proposed AD to clearly state all inspections required by paragraph 
(n) of the proposed AD will be due at the later of 30,000 total flight 
cycles or 4,500 flight cycles from the effective date of the AD. SWA 
stated that, for airplanes which have previously accomplished the 
inspections specified in Boeing Alert Service Bulletin 737-53A1279, 
Revision 1, dated September 2, 2011, paragraph (n) of the proposed AD 
and table 1 of paragraph 1.E., ``Compliance,'' in Boeing Alert Service 
Bulletin 737-53A1279, Revision 2, dated April 21, 2015, currently 
requires inspections 4,500 flight cycles from the last inspection and 
do not specifically take into account those airplanes already doing the 
repetitive inspections.
    We do not agree with the commenter's request. AD 2011-23-05 
required inspections on airplanes with less than 40,000 total flight 
cycles to begin prior to 30,000 total flight cycles or within 90 days 
from November 16, 2011 (the effective date of AD 2011-23-05), whichever 
occurs later. The repetitive inspection intervals of 4,500 flight 
cycles are not changed. The new WFD requirement lowers the initial 
airplane applicability total flight cycles from 40,000 to 30,000. 
Paragraph (n) of this AD addresses airplanes with more than 30,000 
total flight cycles as of the effective date of the AD, and all 
airplanes that have already accomplished the initial inspection or a 
repetitive inspection. These airplanes are to continue the repetitive 
inspections at intervals not to exceed 4,500 flight cycles from the 
last inspection. The commenter's requested change would reset the time 
to the next inspection from the effective date of this AD instead of 
from the last inspection. This would result in a one-time increase in 
the repetitive interval, which would not meet the WFD requirements. We 
have not changed this AD in this regard.

Request To Clarify Inspections in Paragraphs (m) and (n) of the 
Proposed AD

    Boeing requested that we clarify the inspections required in 
paragraph (m)

[[Page 34873]]

and (n) of the proposed AD. Boeing stated that the words ``an 
inspection'' is not specific enough to ensure the required inspections 
will be accomplished.
    We agree with the commenter's request. The wording ``an 
inspection'' could be interpreted incorrectly, and the Part 2 or Part 4 
inspections specified in Boeing Alert Service Bulletin 737-53A1279, 
Revision 2, dated April 21, 2015, may not be accomplished prior to 
installation of the preventive modification.
    We have revised paragraph (m) of this AD to state in part, ``before 
further flight after accomplishing the Part 2 or Part 4 inspections 
specified in this paragraph, and no cracking was found, do ``Part 5--
Preventative Modification'' as specified in the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1279, Revision 2, 
dated April 21, 2015.''
    We have revised paragraph (n) of this AD to state in part, ``before 
further flight after accomplishing the Part 4 inspection specified in 
this paragraph, and no cracking was found, do ``Part 5--Preventative 
Modification'' as specified in the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated April 21, 
2015.''

Request To Remove a Certain Low Frequency Eddy Current (LFEC) 
Inspection

    Boeing requested that we remove the LFEC inspection in paragraph 
(s) of the proposed AD. Boeing stated that paragraph (s) of the 
proposed AD is applicable to Groups 4 through 6 as identified in Boeing 
Alert Service Bulletin 737-53A1279, Revision 2, dated April 21, 2015, 
and that LFEC inspections are not required for Groups 4 through 6.
    We agree with the commenter's request. We have revised paragraph 
(s) of this AD by removing the LFEC inspection requirement.

Request To Clarify Service Information Description

    Boeing requested that we include ``0.50 inch diameter holes'' in 
the first bullet under the Related Service Information Under 1 CFR part 
51 section. Boeing stated that the 0.50 inch hole was one of the main 
updates of Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated 
April 21, 2015.
    We agree with commenter's request and have revised this final rule 
accordingly.

Request To Revise Responsible FAA ACO

    Boeing requested that we revise paragraph (u)(3) of the proposed AD 
to reference the Los Angeles ACO instead of the Seattle ACO.
    We agree with the commenter's request. In July 2014, the Los 
Angeles ACO assumed responsibility for the out-of-production Model 737 
airplanes. We have revised paragraph (u)(3) of this AD and the engineer 
contact information accordingly.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD with the changes described previously, and minor editorial 
changes. We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM for correcting the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Service Bulletin 737-53A1279, Revision 2, 
dated April 21, 2015. The service information describes procedures for 
the following actions.
     Inspections of wire penetration holes, 0.50 inch diameter 
holes, standoff/tooling holes, and the production fastener holes for 
cracking in the forward cargo compartment frames and frame 
reinforcements, between stringer (S) S-19 and S-22, on both left and 
right sides of the airplane.
     A preventive modification of frames between S-19 and S-22.
     Post-modification inspections.
     Repairs.
    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.

Costs of Compliance

    We estimate that this AD affects 605 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
----------------------------------------------------------------------------------------------------------------
Inspections [retained actions    16 work-hours x $85 per              $0  $1,360 per          $822,800 per
 from AD 2011-23-05].             hour = $1,360 per                        inspection cycle.   inspection cycle.
                                  inspection cycle.
Inspections [new action].......  32 work-hours x $85 per               0  $2,720 per          $1,645,600 per
                                  hour = $2,720 per                        inspection cycle.   inspection cycle.
                                  inspection cycle.
Modification [new action]......  32 work-hours x $85 per               0  $2,720............  $1,645,600
                                  hour = $2,720.
----------------------------------------------------------------------------------------------------------------

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

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                  Action                                Labor cost                 Parts cost        product
----------------------------------------------------------------------------------------------------------------
Repair....................................  18 work-hours x $85 per hour =                  $0           $1,530
                                             $1,530.
----------------------------------------------------------------------------------------------------------------


[[Page 34874]]

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) 
2011-23-05, Amendment 39-16856 (76 FR 67343, November 1, 2011), and 
adding the following new AD:

2016-11-04 The Boeing Company: Amendment 39-18531; Docket No. FAA-
2015-5812; Directorate Identifier 2015-NM-077-AD.

(a) Effective Date

    This AD is effective July 6, 2016.

(b) Affected ADs

    This AD replaces AD 2011-23-05, Amendment 39-16856 (76 FR 67343, 
November 1, 2011) (``AD 2011-23-05'').

(c) Applicability

    (1) This AD applies to all The Boeing Company Model 737-300, -
400, and -500 series airplanes; certificated in any category.
    (2) Installation of Supplemental Type Certificate (STC) 
ST01219SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/
rgstc.nsf/0/ebd1cec7b301293e86257cb30045557a/$FILE/ST01219SE.pdf) 
does not affect the ability to accomplish the actions required by 
this AD. Therefore, for airplanes on which STC ST01219SE is 
installed, a ``change in product'' alternative method of compliance 
(AMOC) approval request is not necessary to comply with the 
requirements of 14 CFR 39.17.

(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 indicates the fuselage frames and frame 
reinforcements are subject to widespread fatigue damage (WFD). We 
are issuing this AD to detect and correct fatigue cracking of the 
fuselage frames and frame reinforcements, 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) Retained Inspection, With References to Terminating Actions

    This paragraph restates the requirements of paragraph (g) of AD 
2011-23-05, with references to terminating actions. At the 
applicable time specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011, except as required by paragraphs (k)(1), (k)(2), 
and (k)(4) of this AD: Do a high frequency eddy current (HFEC) 
surface or HFEC hole/edge inspection for any cracking of the 1.04-
inch nominal diameter wire penetration hole in the frame and frame 
reinforcement between stringer (S) S-20 and S-21, in accordance with 
Part 2 of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-53A1279, Revision 1, dated September 2, 2011. 
Accomplishment of the applicable inspections required by paragraphs 
(m) and (n) of this AD terminates the inspections required by this 
paragraph. Accomplishment of the modification required by paragraph 
(p) of this AD terminates the inspections required by this paragraph 
for the modified area only.

(h) Retained Repetitive Inspections, With References to Terminating 
Actions

    This paragraph restates the requirements of paragraph (h) of AD 
2011-23-05, with references to terminating actions. Within 4,500 
flight cycles after accomplishment of the most recent inspection 
specified in Part 2 or Part 4 of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011, or within 90 days after November 16, 2011 (the 
effective date of AD 2011-23-05), whichever occurs later: Do an HFEC 
hole/edge inspection for cracking of the 1.04-inch nominal diameter 
wire penetration hole in the frame and frame reinforcement between 
S-20 and S-21, in accordance with Part 4 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1279, Revision 
1, dated September 2, 2011. Repeat the inspection thereafter at 
intervals not to exceed 4,500 flight cycles. Accomplishment of the 
applicable inspections required by paragraphs (m) and (n) of this 
AD, terminates the inspections required by this paragraph. 
Accomplishment of the modification specified in paragraph (j) or (p) 
of this AD terminates the repetitive inspections required by this 
paragraph for the modified area only. Accomplishment of the repair 
specified in paragraph (i) of this AD terminates the repetitive 
inspections required by this paragraph for the repaired area only.

(i) Retained Repair, With No Changes

    This paragraph restates the requirements of paragraph (i) of AD 
2011-23-05, with no changes. If any cracking is found during any 
inspection required by paragraph (g) or (h) of this AD: Before 
further flight, repair the crack including doing all applicable 
related investigative and corrective actions, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1279, Revision 1, dated September 2, 2011, except as required by 
paragraph (k)(3) of this AD. All applicable related investigative 
and corrective actions must be done before further flight. 
Accomplishment of the requirements of this paragraph terminates the 
repetitive inspection requirements of paragraph (h) of this AD for 
the repaired location of that frame.

(j) Retained Optional Terminating Action, With New Limitation

    This paragraph restates the optional action provided in 
paragraph (j) of AD 2011-23-05, with a new limitation. 
Accomplishment of the preventive modification before the effective 
date of this AD, including doing all related investigative and 
applicable corrective actions, specified in Part 5 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1279, Revision 1, dated September 2, 2011, except as required by 
paragraph (k)(3) of this AD, terminates the repetitive inspection 
requirements of paragraph (h) of this AD for the modified

[[Page 34875]]

location of that frame, provided the modification is done before 
further flight after an inspection required by paragraph (g) or (h) 
of this AD has been done, and no cracking was found on that frame 
location during that inspection.

(k) Retained Exceptions to Service Information Specifications, With No 
Changes

    This paragraph restates the requirements of paragraph (k) of AD 
2011-23-05, with no changes. The following exceptions apply as 
specified in paragraphs (g), (i), and (j) of this AD.
    (1) Where paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1279, Revision 1, dated September 2, 2011, 
refers to a compliance time ``from date on Revision 1 of this 
service bulletin,'' this AD requires compliance within the specified 
compliance time after November 16, 2011 (the effective date of AD 
2011-23-05).
    (2) For airplanes meeting all of the criteria specified in 
paragraphs (k)(2)(i), (k)(2)(ii), and (k)(2)(iii) of this AD: The 
compliance time for the initial inspection specified in Part 2 of 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-53A1279, Revision 1, dated September 2, 2011, and required by 
paragraph (g) of this AD, may be extended to 90 days after November 
16, 2011 (the effective date of AD 2011-23-05).
    (i) Model 737-300 series airplanes in Group 1, line numbers 1001 
through 2565 inclusive;
    (ii) Airplanes that have accumulated 40,000 or more total flight 
cycles as of November 16, 2011 (the effective date of AD 2011-23-
05); and
    (iii) Airplanes on which the modification specified in Boeing 
Service Bulletin 737-53-1273, dated September 20, 2006; Revision 1, 
dated December 21, 2006; Revision 2, dated June 4, 2007; Revision 3, 
dated December 7, 2009; or Revision 4, dated July 23, 2010; has been 
done, including any configuration or deviation that has been 
approved as an AMOC during accomplishment of these service 
bulletins, by the Boeing Commercial Airplanes Organization 
Designation Authorization (ODA) that has been authorized by the 
Manager, Seattle Aircraft Certification Office (ACO) or Los Angeles 
ACO to make those findings.
    (3) Where Boeing Alert Service Bulletin 737-53A1279, Revision 1, 
dated September 2, 2011, specifies to contact Boeing for appropriate 
repair instructions: Before further flight, repair the crack using a 
method approved in accordance with the procedures specified in 
paragraph (u) of this AD.
    (4) The ``Condition'' column of paragraph 1.E., ``Compliance,'' 
of Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011, refers to total flight cycles ``at the date of/on 
this service bulletin.'' However, this AD applies to the airplanes 
with the specified total flight cycles as of November 16, 2011 (the 
effective date of AD 2011-23-05).

(l) Retained Credit for Previous Actions, With No Changes

    This paragraph restates the requirements of paragraph (l) of AD 
2011-23-05, with no changes. Actions done in accordance with Boeing 
Alert Service Bulletin 737-53A1279, dated December 18, 2007, before 
November 16, 2011 (the effective date of AD 2011-23-05), are 
acceptable for compliance with the corresponding actions required by 
paragraphs (g), (h), (i), and (j) of this AD.

(m) New Requirement of This AD: Inspections of Frames and Frame 
Reinforcements Between S-19 and S-22 for Certain Airplanes on Which 
Certain Inspections Have Not Been Accomplished

    For airplanes identified as Groups 1 through 6, Configuration 3, 
in Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated 
April 21, 2015, with 30,000 total flight cycles or fewer as of the 
effective date of this AD, on which any inspections specified in 
Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011, have not been accomplished: Except as required by 
paragraphs (t)(1) and (t)(2) of this AD, at the applicable time 
specified in table 1 of paragraph 1.E., ``Compliance,'' of Boeing 
Alert Service Bulletin 737-53A1279, Revision 2, dated April 21, 
2015, or within 4,500 flight cycles after the effective date of this 
AD, whichever occurs later, do inspections for cracking at certain 
locations in the frames and frame reinforcements in accordance with 
``Part 2--Initial Detail and HFEC Inspection'' of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1279, Revision 
2, dated April 21, 2015. Repeat the inspections for cracking at 
certain locations in the frames and frame reinforcements as 
specified in ``Part 4--Repeat Detail and HFEC Inspections'' of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1279, Revision 2, dated April 21, 2015, thereafter at the 
applicable interval specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated April 
21, 2015; or, before further flight after accomplishing the Part 2 
or Part 4 inspections specified in this paragraph, and no cracking 
was found, do ``Part 5--Preventative Modification'' as specified in 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-53A1279, Revision 2, dated April 21, 2015. Accomplishment of the 
preventive modification specified in this paragraph terminates the 
repetitive inspections required by this paragraph for the modified 
area only. Do all actions specified in this paragraph in accordance 
with Accomplishment Instructions of Boeing Alert Service Bulletin 
737-53A1279, Revision 2, dated April 21, 2015.

(n) New Requirement of This AD: Inspections of Frames and Frame 
Reinforcements Between S-19 and S-22 for Groups 1-6, Configuration 3, 
Airplanes

    For airplanes identified as Groups 1 through 6, Configuration 3, 
in Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated 
April 21, 2015, with more than 30,000 total flight cycles as of the 
effective date of this AD, or that have been inspected as specified 
in Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011: Except as required by paragraphs (t)(1) and 
(t)(2) of this AD, at the applicable time specified in table 1 of 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1279, Revision 2, dated April 21, 2015, do inspections for 
cracking at certain locations of the frames and frame reinforcements 
in accordance with ``Part 4--Repeat Detail and HFEC Inspections'' of 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-53A1279, Revision 2, dated April 21, 2015. Repeat the 
inspections thereafter at the applicable interval specified in 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1279, Revision 2, dated April 21, 2015; or, before further 
flight after accomplishing the Part 4 inspection specified in this 
paragraph, and no cracking was found, do ``Part 5--Preventative 
Modification'' as specified in the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated April 
21, 2015. Accomplishment of the preventive modification specified in 
this paragraph terminates the repetitive inspections required by 
this paragraph for the modified area only.

(o) New Requirement of This AD: Repairs

    If any crack is found during any inspection required by 
paragraph (m) or (n) of this AD: Before further flight, repair, in 
accordance with ``Part 3--Repair'' of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1279, Revision 
2, dated April 21, 2015, except where Boeing Alert Service Bulletin 
737-53A1279, Revision 2, dated April 21, 2015, specifies to contact 
Boeing for damage removal and repair instructions, repair before 
further flight using a method approved in accordance with the 
procedures specified in paragraph (u) of this AD. Accomplishing a 
repair terminates the inspections required by paragraphs (m) and (n) 
of this AD in the repaired area only. Accomplishment of a repair 
terminates the modification required by paragraph (p) of this AD at 
the repaired location only.

(p) New Requirement of This AD: Preventative Modification of the Frames 
Between S-19 and S-22

    For airplanes identified as Groups 1 through 6, Configuration 3, 
in Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated 
April 21, 2015: Except as required by paragraphs (t)(1) and (t)(2) 
of this AD, at the applicable time specified in table 2 of paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-53A1279, 
Revision 2, dated April 21, 2015, do the preventive modification of 
the frames between S-19 and S-22, in accordance with ``Part 5--
Preventative Modification'' of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated April 
21, 2015. Accomplishment of the modification required by this 
paragraph terminates the requirements of paragraphs (g), (h), (m), 
and (n) of this AD for the modified location only.

(q) New Requirement of This AD: Inspections of Preventive Modification 
for Groups 1-3, Configuration 1, Airplanes

    For airplanes identified as Groups 1 through 3, Configuration 1, 
in Boeing Alert

[[Page 34876]]

Service Bulletin 737-53A1279, Revision 2, dated April 21, 2015: 
Except as required by paragraph (t)(1) of this AD, at the applicable 
time specified in table 3 of paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated April 
21, 2015, do HFEC, LFEC, and detailed inspections for cracking in 
accordance with ``Part 7--INSPECTION OF PREVENTATIVE MODIFICATION'' 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-53A1279, Revision 2, dated April 21, 2015. Repeat the 
inspections thereafter at the applicable interval specified in 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1279, Revision 2, dated April 21, 2015. If any cracking is 
found during any inspection required by this paragraph, before 
further flight, repair using a method approved in accordance with 
the procedures specified in paragraph (u) of this AD.

(r) New Requirement of This AD: Inspections of Preventive Modification 
for Groups 1-6, Configuration 2, Airplanes

    For airplanes identified as Groups 1 through 6, Configuration 2, 
in Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated 
April 21, 2015: Except as required by paragraph (t)(1) of this AD, 
at the applicable time specified in table 4 or table 6 of paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-53A1279, 
Revision 2, dated April 21, 2015, do HFEC, LFEC, and detailed 
inspections for cracking in accordance with ``Part 8--INSPECTION OF 
PREVENTATIVE MODIFICATION'' of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated April 
21, 2015. Repeat the inspections thereafter at the applicable 
interval specified in table 4 or table 6 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1279, 
Revision 2, dated April 21, 2015. If any cracking is found during 
any inspection required by this paragraph, before further flight, 
repair using a method approved in accordance with the procedures 
specified in paragraph (u) of this AD.

(s) New Requirement of This AD: Inspections of Preventive Modification 
for Groups 4-6, Configuration 1, Airplanes

    For airplanes identified as Groups 4 through 6, Configuration 1, 
in Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated 
April 21, 2015: At the applicable time specified in table 5 of 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1279, Revision 2, dated April 21, 2015, except as required by 
paragraph (t)(1) of this AD: Do HFEC and detailed inspections for 
cracking in accordance with ``Part 7--INSPECTION OF PREVENTATIVE 
MODIFICATION'' of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-53A1279, Revision 2, dated April 21, 2015. 
Repeat the inspections thereafter at the applicable time specified 
in paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1279, Revision 2, dated April 21, 2015. If any cracking is 
found during any inspection required by this paragraph, before 
further flight, repair using a method approved in accordance with 
the procedures specified in paragraph (u) of this AD.

(t) New Requirement of This AD: Exceptions to Service Bulletin 
Specifications

    (1) Where paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1279, Revision 2, dated April 21, 2015, 
refers to a compliance time ``after the Revision 2 date of this 
service bulletin,'' this AD requires compliance within the specified 
compliance time after the effective date of this AD.
    (2) The ``Condition'' column in table 1 and table 2 of paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-53A1279, 
Revision 2, dated April 21, 2015, refers to total flight cycles ``at 
the Revision 2 date of this service bulletin.'' However, this AD 
applies to the airplanes with the specified total flight cycles as 
of the effective date of this AD.

(u) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles 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 (v)(1) of this AD. Information may be 
emailed to: [email protected].
    (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 ODA that has 
been authorized by the Manager, Los Angeles ACO, to make those 
findings. To be approved, the repair method, modification deviation, 
or alteration deviation must meet the certification basis of the 
airplane and the approval must specifically refer to this AD.
    (4) AMOCs approved for the ADs in paragraphs (u)(4)(i) through 
(u)(4)(iii) of this AD are approved as AMOCs for the corresponding 
provisions of this AD.
    (i) AD 2009-02-06, Amendment 39-15796 (74 FR 10469, March 11, 
2009).
    (ii) AD 2009-02-06 R1, Amendment 39-16015 (74 FR 45979, 
September 8, 2009).
    (iii) AD 2011-23-05.

(v) Related Information

    (1) For more information about this AD, contact Galib Abumeri, 
Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles ACO, 
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5324; fax: 562-627-5210; email: [email protected].
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (w)(5) and (w)(6) of this AD.

(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 
July 6, 2016.
    (i) Boeing Alert Service Bulletin 737-53A1279, Revision 2, dated 
April 21, 2015.
    (ii) Reserved.
    (4) The following service information was approved for IBR on 
November 16, 2011 (76 FR 67343, November 1, 2011).
    (i) Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011.
    (ii) Reserved.
    (5) For Boeing service information identified in this AD, 
contact Boeing Commercial Airplanes, Attention: Data & Services 
Management, P. O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; 
telephone 206-544-5000, extension 1; fax 206-766-5680; Internet 
https://www.myboeingfleet.com.
    (6) You may view this 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.
    (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 May 18, 2016.
Dionne Palermo,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.

[FR Doc. 2016-12329 Filed 5-31-16; 8:45 am]
 BILLING CODE 4910-13-P