82 FR 23507 - Airworthiness Directives; The Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 82, Issue 98 (May 23, 2017)

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

[Federal Register Volume 82, Number 98 (Tuesday, May 23, 2017)]
[Rules and Regulations]
[Pages 23507-23509]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-10263]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-9434; Directorate Identifier 2016-NM-136-AD; 
Amendment 39-18896; AD 2017-10-22]
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 adopting a new airworthiness directive (AD) for certain 
The Boeing Company Model 737-600, -700, -700C, -800, and -900 series 
airplanes. This AD was prompted by an evaluation by the design approval 
holder (DAH) indicating that the web lap splices in the aft pressure 
bulkhead are subject to widespread fatigue damage (WFD). This AD 
requires repetitive inspections of the web lap splices in the aft 
pressure bulkhead for cracking of the fastener holes, and repair if 
necessary. We are issuing this AD to address the unsafe condition on 
these products.

DATES: This AD is effective June 27, 2017.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of June 27, 
2017.

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-
9434.

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-
9434; 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: Alan Pohl, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6450; fax: 425-917-6590; email: [email protected].

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 certain The Boeing Company 
Model 737-600, -700, -700C, -800, and -900 series airplanes. The NPRM 
published in the Federal Register on December 5, 2016 (81 FR 87496) 
(``the NPRM''). The NPRM was prompted by an evaluation by the DAH 
indicating that the web lap splices in the aft pressure bulkhead are 
subject to WFD. The NPRM proposed to require repetitive inspections of 
the web lap splices in the aft pressure bulkhead for cracking of the 
fastener holes, and repair if necessary. We are issuing this AD to 
detect and correct cracks of the web lap splices in the aft pressure 
bulkhead, which could result in possible rapid decompression and loss 
of 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, United Airlines, and commenter Razia Khan concurred with 
the content of the NPRM.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that installation of winglets, as 
provided in Supplemental Type Certificate (STC) ST00830SE, does not 
affect the ability to accomplish the actions proposed in the NPRM.
    We agree with the commenter. We have redesignated paragraph (c) of 
the proposed AD as paragraph (c)(1) of this AD and added paragraph 
(c)(2) to this AD to state that installation of STC ST00830SE does not 
affect the ability to accomplish the actions required by this AD. 
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 Omit Inspections of Existing Repairs

    Southwest Airlines (SWA) asked that we include provisions for 
airplanes on which repairs have been accomplished previously per the 
structural repair manual or per an Organization Designation 
Authorization (ODA) signed FAA Form 8100-9 to omit the inspections at 
the repair locations. SWA noted that these existing repairs would 
inhibit the inspections specified in paragraph (g) of the proposed AD. 
SWA added that including follow-on actions as an alternative to the 
actions specified in Boeing Alert Service Bulletin 737-53A1353, dated 
July 21, 2016, when an existing repair inhibits the inspections 
required by paragraph (g) of the proposed AD, would also be acceptable.
    We do not agree with the commenter's request. We acknowledge that 
SWA is requesting relief from additional approval for actions for 
existing repaired locations. However, SWA did not identify any specific 
structural repair manual (SRM) repairs or provide a general repair 
description of repairs previously approved by the Boeing ODA per an FAA 
Form 8100-9. These criteria have been published by Boeing in related 
service information for similar issues, but not for this particular 
issue. Under the provisions of paragraph (i) of this AD, we will 
consider requests for approval of an AMOC if appropriate data are 
submitted to substantiate that the method would provide an acceptable 
level of safety. We have made no change to this AD in this regard.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the

[[Page 23508]]

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 737-53A1353, dated July 
21, 2016. The service information describes procedures for a low 
frequency eddy current inspection to detect cracking of each web lap 
splice of the aft pressure bulkhead at the fastener row common to the 
stiffener, and a high frequency eddy current inspection to detect 
cracking of each web lap splice of the aft pressure bulkhead at the 
fastener row not common to the stiffener. 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 693 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
               Action                         Labor cost             Cost per product     Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
Inspections........................  26 work-hours x $85 per      $2,210 per inspection   $1,531,530 per
                                      hour = $2,210 per            cycle.                  inspection cycle.
                                      inspection cycle.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable 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):

2017-10-22 The Boeing Company: Amendment 39-18896; Docket No. FAA-
2016-9434; Directorate Identifier 2016-NM-136-AD.

(a) Effective Date

    This AD is effective June 27, 2017.

(b) Affected ADs

    None.

(c) Applicability

    (1) 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 737-53A1353, dated 
July 21, 2016.
    (2) Installation of Supplemental Type Certificate (STC) 
ST00830SE [http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/184DE9A71EC3FA5586257EAE00707DA6?OpenDocument&Highlight=st00830se] 
does not affect the ability to accomplish the actions required by 
this AD. 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.

(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 web lap splices in the aft pressure 
bulkhead are subject to widespread fatigue damage (WFD). We are 
issuing this AD to detect and correct cracks of the web lap splices 
in the aft pressure bulkhead, which could result in possible rapid 
decompression and loss of structural integrity of the airplane.

(f) Compliance

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

(g) Repetitive Inspections

    Except as provided by paragraph (h) of this AD, at the 
applicable time specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-53A1353, dated July 21, 2016: Do a 
low frequency eddy current (LFEC) inspection to detect cracking of 
each web lap splice of the aft pressure bulkhead at the fastener row 
common to the stiffener, and a high frequency eddy current (HFEC) 
inspection to detect cracking of each web lap splice of the aft 
pressure bulkhead at the fastener row not common to the stiffener, 
in accordance with the

[[Page 23509]]

Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1353, dated July 21, 2016.
    (1) If no crack is found: Repeat the inspections thereafter at 
the applicable times specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-53A1353, dated July 21, 2016.
    (2) If any crack is found: Do the actions specified in 
paragraphs (g)(2)(i) and (g)(2)(ii) of this AD.
    (i) Repair the crack before further flight using a method 
approved in accordance with the procedures specified in paragraph 
(i) of this AD. Although Boeing Alert Service Bulletin 737-53A1353, 
dated July 21, 2016, specifies to contact Boeing for repair 
instructions, and specifies that action as ``RC'' (Required for 
Compliance), this AD requires repair as specified in this paragraph.
    (ii) On areas that are not repaired, repeat the inspections 
thereafter at the applicable times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1353, dated 
July 21, 2016.

(h) Service Information Exception

    Where paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-53A1353, dated July 21, 2016, specifies a compliance 
time ``after the Original Issue date of this Service Bulletin,'' 
this AD requires compliance within the specified compliance time 
after the effective date of this AD.

(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: [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 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) Except as required by paragraph (g)(2)(i) of this AD: For 
service information that contains steps that are labeled as 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 Alan Pohl, Aerospace 
Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 1601 Lind 
Avenue SW., Renton, WA 98057-3356; phone: 425-917-6450; fax: 425-
917-6590; email: [email protected].

(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 737-53A1353, dated July 21, 
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 May 10, 2017.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2017-10263 Filed 5-22-17; 8:45 am]
 BILLING CODE 4910-13-P