[Federal Register Volume 82, Number 100 (Thursday, May 25, 2017)]
[Rules and Regulations]
[Pages 24025-24027]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-10265]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-8848; Directorate Identifier 2016-NM-054-AD; 
Amendment 39-18895; AD 2017-10-21]
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 737-300, -400, and -500 series airplanes. This 
AD was prompted by an evaluation by the design approval holder (DAH) 
indicating that the fuselage skin is subject to widespread fatigue 
damage (WFD). This AD requires modification of the lap joint and 
repetitive inspections for cracking of the skin at critical fastener 
rows. We are issuing this AD to address the unsafe condition on these 
products.

DATES: This AD is effective June 29, 2017.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of June 29, 
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 
90740-5600; 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-
8848.

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-
8848; 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: Jennifer Tsakoumakis, Aerospace 
Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft 
Certification Office (ACO), 3960 Paramount Boulevard, Lakewood, CA 
90712-4137; phone: 562-627-5264; fax: 562-627-5210; 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 737-300, -400, and 0500 series airplanes. The NPRM published in 
the Federal Register on August 30, 2016 (81 FR 59541) (``the NPRM''). 
The NPRM was prompted by an evaluation by the DAH indicating that the 
fuselage skin is subject to WFD. The NPRM proposed to require 
modification of the lap joint, including related investigative actions 
and corrective actions if necessary. The NPRM also proposed to require 
repetitive post-modification inspections for cracking of the skin at 
critical fastener rows, and corrective actions if necessary. We are 
issuing this AD to detect and correct cracks at the lap joint skin that 
could link up and result in 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.

Request To Remove Certain References in Terminating Action

    Boeing requested that we remove certain references to AD 2015-16-
08, Amendment 39-18233 (80 FR 51450, August 25, 2015) (``AD 2015-16-
08''). Boeing pointed out that paragraphs (i), (j), and (k) of AD 2015-
16-08 refer to a location (S-4R, Station (STA) 908-STA 1016) that is 
outside of the area affected by the modification specified in paragraph 
(g) of the proposed AD (S-4L and S-4R, STA 360-STA 908).
    We agree with the commenter. Specifically, paragraphs (g) and (h) 
of AD 2015-16-08 apply to the modification area specified in this AD, 
but paragraphs (i), (j), and (k) of AD 2015-16-08 do not. Therefore, we 
have revised paragraph (k) of this AD to remove reference to paragraphs 
(i), (j), and (k) of AD 2015-16-08.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that accomplishing the supplemental 
type certificate (STC) ST01219SE does not affect the actions specified 
in the NPRM.
    We concur 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 ST01219SE 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.

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 737-53A1343, dated March 
25, 2016. The service information describes procedures for modification 
of the lap joint, including related investigative actions and 
corrective actions if necessary. The service information also describes 
procedures for post-modification inspections for cracking of the skin 
at critical fastener rows, and corrective actions if necessary. This 
service information is reasonably available because the interested 
parties

[[Page 24026]]

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 115 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
----------------------------------------------------------------------------------------------------------------
Lap joint skin modification......  2,142 work-hours x        $12,500  $194,570............  $22,375,550.
                                    $85 per hour =
                                    $182,070 per
                                    modification.
Post-Modification inspection.....  102 work-hours x $85            0  8,670 per inspection  997,050 per
                                    per hour = $8,670                  cycle.                inspection cycle.
                                    per 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):

2017-10-21 The Boeing Company: Amendment 39-18895; Docket No. FAA-
2016-8848; Directorate Identifier 2016-NM-054-AD.

(a) Effective Date

    This AD is effective June 29, 2017.

(b) Affected ADs

    This AD affects AD 2015-16-08, Amendment 39-18233 (80 FR 51450, 
August 25, 2015) (``AD 2015-16-08'').

(c) Applicability

    (1) This AD applies to The Boeing Company Model 737-300, -400, 
and -500 series airplanes, certificated in any category, as 
identified in Boeing Alert Service Bulletin 737-53A1343, dated March 
25, 2016; except for Group 5 airplanes identified in Boeing Alert 
Service Bulletin 737-53A1343, dated March 25, 2016.
    (2) Installation of Supplemental Type Certificate (STC) 
ST01219SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/EBD1CEC7B301293E86257CB30045557A?OpenDocument&Highlight=st01219se) 
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) indicating that the fuselage skin is subject to 
widespread fatigue damage (WFD). We are issuing this AD to detect 
and correct cracks at the lap joint skin that could link up and 
result in 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) Lap Joint Skin Modification

    Before the accumulation of 50,000 total flight cycles, or within 
3,000 flight cycles after the effective date of this AD, whichever 
occurs later: Modify the lap joint skin, including doing all 
applicable related investigative and corrective actions, in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-53A1343, dated March 25, 2016, except as 
required by paragraph (i) of this AD. Do all applicable related 
investigative and corrective actions before further flight.

(h) Inspection of the Critical Fastener Rows

    Within 38,000 flight cycles after modifying the lap joint skin 
as required by paragraph (g) of this AD: Inspect the skin at 
critical fastener rows by doing the actions specified in paragraph 
(h)(1) or (h)(2) of this AD, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1343, dated 
March 25, 2016. If any crack is found during any inspection, repair 
before further flight using a method approved in accordance with the 
procedures specified in paragraph (l) of this AD. Repeat the 
inspection thereafter at intervals not to exceed 2,000 flight cycles 
in unrepaired areas.
    (1) From the inside of the airplane: Do a low frequency eddy 
current (LFEC) inspection for any crack in the skin at the critical 
fastener row, and a medium frequency eddy current (MFEC) inspection 
for any crack in the skin at the critical fastener row.
    (2) From the outside of the airplane: Do a LFEC inspection for 
any crack in the fuselage skin.

[[Page 24027]]

(i) Exception to Service Information Specifications

    Although Boeing Alert Service Bulletin 737-53A1343, dated March 
25, 2016, specifies to contact Boeing for repair instructions, and 
specifies that action as ``RC'' (Required for Compliance), this AD 
requires repair before further flight using a method approved in 
accordance with the procedures specified in paragraph (l) of this 
AD.

(j) AD Provisions for Part 26 Supplemental Inspections

    Table 5 of paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1343, dated March 25, 2016, specifies post-
modification airworthiness limitation inspections in compliance with 
14 CFR 25.571(a)(3) at the modified locations, which support 
compliance with 14 CFR 121.1109(c)(2) or 129.109(b)(2). As 
airworthiness limitations, these inspections are required by 
maintenance and operational rules. It is therefore unnecessary to 
mandate them in this AD. Deviations from these inspections require 
FAA approval, but do not require an alternative method of 
compliance.

(k) Terminating Action for Certain Requirements of AD 2015-16-08

    Accomplishing the modification required by paragraph (g) of this 
AD terminates the inspections required by paragraphs (g) and (h) of 
AD 2015-16-08 for the modified area only.

(l) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles 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 (m) 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, 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) Except as required by paragraph (i) of this AD: For service 
information that contains steps that are labeled as Required for 
Compliance (RC), the provisions of paragraphs (l)(4)(i) and 
(l)(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.

(m) Related Information

    For more information about this AD, contact Jennifer 
Tsakoumakis, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los 
Angeles ACO, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; 
phone: 562-627-5264; fax: 562-627-5210; email: 
[email protected].

(n) 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 737-53A1343, dated March 25, 
2016.
    (ii) Reserved.
    (3) For Boeing 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 
90740-5600; 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.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2017-10265 Filed 5-24-17; 8:45 am]
 BILLING CODE 4910-13-P