```

[Federal Register Volume 81, Number 225 (Tuesday, November 22, 2016)]
[Rules and Regulations]
[Pages 83657-83660]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-26621]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-5034; Directorate Identifier 2015-NM-172-AD; 
Amendment 39-18702; AD 2016-22-13]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: We are adopting a new airworthiness directive (AD) for all The 
Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER 
series airplanes. This AD was prompted by an evaluation by the design 
approval holder (DAH) indicating that lap splices for certain stringers 
are subject to widespread fatigue damage (WFD). This AD requires 
repetitive inspections for cracking in the lower fastener row of the 
lap splices of certain stringers, and repair if necessary. We are 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective December 27, 2016.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of December 27, 
2016.

ADDRESSES: For service information identified in this final rule, 
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-2016-5034.

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-
5034; 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

[[Page 83658]]

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: 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:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to all The Boeing Company 
Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. 
The NPRM published in the Federal Register on March 29, 2016 (81 FR 
17415) (``the NPRM''). The NPRM was prompted by an evaluation by the 
DAH indicating that the S-14L and S-14R lap splices are subject to WFD. 
The NPRM proposed to require repetitive low frequency eddy current 
inspections for cracking in the lower fastener row of the S-14L and S-
14R lap splices, and repair if necessary. We are issuing this AD to 
detect and correct widespread cracking in the S-14L and S-14R lap 
splices that could rapidly link up and result in possible rapid 
decompression and 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.

Support for the NPRM

    Boeing and a commenter, Jordan Ibsen, supported the content of the 
NPRM.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that accomplishing the supplemental 
type certificate (STC) ST00830SE does not affect compliance with the 
actions specified in the NPRM.
    We agree with the commenter. We have redesignated paragraph (c) of 
the NPRM as (c)(1) and added a new paragraph (c)(2) to this final rule 
to state that installation of STC ST00830SE does not affect the ability 
to accomplish the actions required by this final rule. Therefore, for 
airplanes on which STC ST00830SE 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 Compliance Time

    The European Aviation Safety Agency (EASA) noted that Boeing Alert 
Service Bulletin 737-53A1352, dated October 2, 2015, specifies that the 
existing 737-600/700/800/900 Maintenance Planning Document (MPD), 
Section 9, Airworthiness Limitation Instruction (ALI) Inspection 
Program, is not sufficient to prevent WFD in the S-14L and S-14R lap 
splice, lower fastener rows, between station (STA) 360-540 and STA 727-
887, as the airplane ages. EASA added that this service information 
specifies inspections at principal structural elements (PSEs) 53-30-04-
6, 53-30-04-6a, 53-60-04-6 and 53-60-04-6a before accumulating 54,000 
total flight cycles. However, EASA noted that 737-600/700/800/900 MPD, 
Section 9, C626AOO 1-CMR Table 9-2, Revision August 2012, requires 
doing the inspections before accumulating 50,000 flight cycles; which 
contradicts the initial statement that the ALI inspection program is 
not sufficient to preclude WFD. EASA concluded that if the current ALI 
is not sufficient to preclude WFD, then the 50,000 flight cycles should 
be reduced, rather than increased to 54,000 flight cycles.
    We infer the commenter is requesting that we reduce the 54,000 
flight-cycle compliance time specified in Boeing Alert Service Bulletin 
737-53A1352, Revision 1, dated March 10, 2016 (which is the appropriate 
source of service information for accomplishing the required actions in 
this AD). We do not agree with the request to reduce the compliance 
time. However, we do agree to clarify the WFD analysis. Boeing uses a 
different methodology than the standard damage tolerance analysis for 
evaluating structure that is susceptible to WFD. This methodology can 
sometimes produce a longer initial inspection threshold than the 
baseline maintenance program, but requires more frequent repetitive 
inspections, as in the case of the S-14L and S-14R lap splices. 
Although, for certain airplanes, the initial WFD threshold specified in 
Boeing Alert Service Bulletin 737-53A1352, Revision 1, dated March 10, 
2016, is 4,000 flight cycles more than the ALI threshold; the 
repetitive inspection interval is reduced by 6,000 flight cycles.
    Operators are still required to accomplish the ALI inspections in 
accordance with 14 CFR 91.403(c). However, if the inspections specified 
in Boeing Alert Service Bulletin 737-53A1352, Revision 1, dated March 
10, 2016, and the ALI inspections overlap (same location, inspection 
detail, and technique) then the more restrictive of the two programs 
satisfies both requirements. Since a specific revision of the ALI 
inspections are required by AD 2013-19-23, Amendment 39-17605 (78 FR 
61173, October 3, 2013), Boeing Alert Service Bulletin 737-53A1352, 
Revision 1, dated March 10, 2016, contains an approved AMOC to AD 2013-
19-23, for certain PSEs, after the initial inspections in that service 
bulletin are accomplished. We have not changed this AD in this regard.

Request for Clarification of Extent of Boeing Organization Designation 
Authorization (ODA)

    Southwest Airlines (SWA) asked for clarification that the Boeing 
ODA identified in paragraph (i)(3) of the proposed AD can provide an 
AMOC for any ``repair, modification, or alteration'' that includes the 
authority to approve existing repairs in the inspection area that 
inhibit accomplishment of the AD requirements as terminating action to 
paragraph (g) of the proposed AD. SWA also asked if the ODA has the 
authority to provide alternative inspection procedures for repaired 
areas where the inspection in paragraph (g) of the proposed AD cannot 
be accomplished. Additionally, SWA asked that we clarify that the 
Boeing ODA identified in paragraph (i)(3) of the proposed AD is able to 
issue an AMOC for an existing repair at the S-14 lap joint (where the 
location of the repair inhibits accomplishing the initial inspection), 
provided the repair was approved by any FAA designation authority and 
there are a minimum of three fastener rows above and below the lap 
joint. SWA stated that neither Boeing Alert Service Bulletin 737-
53A1352, dated October 2, 2015, nor the NPRM clearly state how to 
address existing repairs that prevent accomplishment of the inspections 
specified in paragraph (g) of the proposed AD.
    We agree with the commenter that clarification of the extent of the 
authority of the Boeing ODA is necessary. The Boeing ODA includes the 
authority to evaluate existing repairs and provide alternative 
inspection programs in the repaired area, and includes approval of 
alternative inspections as AMOCs if accomplishment of the inspections 
required by paragraph (g) of this AD is inhibited. We have not changed 
this AD in this regard.

[[Page 83659]]

    We infer that SWA is asking if the Boeing ODA can issue a global 
AMOC for the referenced repair. The Boeing ODA does not have that 
authority. We have not received any information from Boeing that 
defines such a repair that would be considered for a global AMOC. If 
Boeing provides supporting data, we will evaluate the data to determine 
if that repair and any associated inspections provide an acceptable 
level of safety. We have not changed this AD in this regard.

Change to This AD

    We have reviewed Boeing Alert Service Bulletin 737-53A1352, 
Revision 1, dated March 10, 2016, and there are no substantial changes. 
Therefore, we have included Boeing Alert Service Bulletin 737-53A1352, 
Revision 1, dated March 10, 2016, as the appropriate source of service 
information for accomplishing in the actions required by paragraph (g) 
of this AD. We have also added a new paragraph (h) to this AD to 
provide credit for actions done prior to the effective date of this AD 
using Boeing Alert Service Bulletin 737-53A1352, dated October 2, 2015. 
We have redesignated subsequent paragraphs 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 737-53A1352, Revision 1, 
dated March 10, 2016. The service information describes procedures for 
low frequency eddy current inspections and repair for cracking in the 
lower fastener row of the S-14L and S-14R lap splices. 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 1,513 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
----------------------------------------------------------------------------------------------------------------
Inspection for Group 1 airplanes   84 work-hours x $85              $0  $7,140 per           $10,502,940 per
 (1,471 airplanes).                 per hour = $7,140                    inspection cycle.    inspection cycle.
                                    per inspection
                                    cycle.
Inspection for Group 2 airplanes   65 work-hours x $85               0  $5,525 per           $232,050 per
 (42 airplanes).                    per hour = $5,525                    inspection cycle.    inspection cycle.
                                    per inspection
                                    cycle.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that enables us to provide cost 
estimates for the on-condition actions 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

    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 adding the following new airworthiness 
directive (AD):

2016-22-13 The Boeing Company: Amendment 39-18702; Docket No. FAA-
2016-5034; Directorate Identifier 2015-NM-172-AD.

(a) Effective Date

    This AD is effective December 27, 2016.

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to all The Boeing Company Model 737-600, -
700, -700C, -800, -900, and -900ER series airplanes, certificated in 
any category.
    (2) Installation of Supplemental Type Certificate (STC) 
ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSTC.nsf/0/38B606833BBD98B386257FAA00602538?OpenDocument&Highlight=st00830se) 
does not affect the ability to accomplish the actions required by 
this AD. Therefore, for airplanes on which STC

[[Page 83660]]

ST00830SE 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) indicating that the stringer (S)-14L and S-14R lap 
splices are subject to widespread fatigue damage (WFD). We are 
issuing this AD to detect and correct widespread cracking in the S-
14L and S-14R lap splices that could rapidly link up and result in 
possible rapid decompression and reduced structural integrity of the 
airplane.

(f) Compliance

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

(g) Repetitive Inspections

    At the applicable compliance time specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1352, 
Revision 1, dated March 10, 2016, do a low frequency eddy current 
inspection for cracking of the lower fastener row of S-14L and S-14R 
lap splices, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1352, Revision 1, dated March 
10, 2016. Repeat the inspection thereafter at the applicable times 
specified in paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-53A1352, Revision 1, dated March 10, 2016. If any 
cracking is found, before further flight, repair using a method 
approved in accordance with the procedures specified in paragraph 
(i) of this AD.

(h) Credit for Previous Actions

    This paragraph provides credit for the actions required by 
paragraph (g) of this AD, if those actions were performed before the 
effective date of this AD using Boeing Alert Service Bulletin 737-
53A1352, dated October 2, 2015.

(i) 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 (j) 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 the certification basis of the airplane, and the approval must 
specifically refer to this AD.
    (4) For service information that contains steps that are labeled 
as Required for Compliance (RC), the provisions of paragraphs 
(i)(4)(i) and (i)(4)(ii) of this AD apply.
    (i) The steps labeled as RC, including substeps under an RC step 
and any figures identified in an RC step, must be done to comply 
with the AD. If a step or substep is labeled ``RC Exempt,'' then the 
RC requirement is removed from that step or substep. An AMOC is 
required for any deviations to RC steps, including substeps and 
identified figures.
    (ii) Steps not labeled as RC may be deviated from using accepted 
methods in accordance with the operator's maintenance or inspection 
program without obtaining approval of an AMOC, provided the RC 
steps, including substeps and identified figures, can still be done 
as specified, and the airplane can be put back in an airworthy 
condition.

(j) Related Information

    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.

(k) 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.
    (i) Boeing Alert Service Bulletin 737-53A1352, Revision 1, dated 
March 10, 2016.
    (ii) Reserved.
    (3) 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.
    (4) 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.
    (5) 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 October 21, 2016.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-26621 Filed 11-21-16; 8:45 am]
 BILLING CODE 4910-13-P
```