82 FR 9492 - Airworthiness Directives; The Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 82, Issue 24 (February 7, 2017)

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD was prompted by reports of skin cracking found at the corners of the aft entry and aft galley doorways. This AD requires repetitive inspections for cracking of the fuselage skin assembly and the bear strap at the corners of the aft entry and aft galley doorways, and repair if necessary, which terminates the repetitive inspections of the repaired areas. We are issuing this AD to address the unsafe condition on these products.

[Federal Register Volume 82, Number 24 (Tuesday, February 7, 2017)]
[Rules and Regulations]
[Pages 9492-9495]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-01533]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-8186; Directorate Identifier 2016-NM-074-AD; 
Amendment 39-18784; AD 2017-02-05]
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 all The 
Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. This AD was prompted by reports of skin cracking found at 
the corners of the aft entry and aft galley doorways. This AD requires 
repetitive inspections for cracking of the fuselage

[[Page 9493]]

skin assembly and the bear strap at the corners of the aft entry and 
aft galley doorways, and repair if necessary, which terminates the 
repetitive inspections of the repaired areas. We are issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective March 14, 2017.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of March 14, 
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-2016-8186.

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-
8186; 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 by adding an AD that would apply to all The Boeing Company 
Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. The 
NPRM published in the Federal Register on August 22, 2016 (81 FR 
56538). The NPRM was prompted by reports of skin cracking found at the 
corners of the aft entry and aft galley doorways. The NPRM proposed to 
require repetitive inspections for cracking of the corners of the aft 
entry and aft galley doorways; and repair if necessary, which 
terminates the repetitive inspections of the repaired areas. We are 
issuing this AD to detect and correct cracking of the corners of the 
aft entry and aft galley doorways, which could result in rapid 
decompression and consequent 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 supplemental 
type certificate (STC) ST01219SE does not affect compliance with the 
actions specified in the NPRM.
    We agree with the commenter. We have redesignated paragraph (c) of 
the proposed AD as (c)(1) 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 final rule. Therefore, for 
airplanes on which STC ST01219SE is installed, a ``change in product'' 
AMOC approval request is not necessary to comply with the requirements 
of 14 CFR 39.17.

Request To Clarify the Description of the Inspection

    Boeing asked that we clarify the description of the inspection in 
the ``Related Service Information under 1 CFR part 51'' section of the 
NPRM. Boeing requested that we change the inspection type from 
``external detailed inspections'' to ``external low frequency eddy 
current and detailed inspections.'' Boeing also requested that we 
change the inspection location from ``the skin assembly of the corners 
of the aft entry'' to ``the skin assembly and the bear strap of the 
corners of the aft entry.'' Boeing indicated that the revised wording 
reflects the actions specified in the service information.
    We agree with the commenter that clarification is necessary. We 
have added the specified language to the ``Related Service Information 
under 1 CFR part 51'' section in this final rule accordingly.

Request To Clarify the Description of the Unsafe Condition

    Boeing asked that we revise the unsafe condition specified in 
paragraph (e) and the inspection requirement specified in paragraph (h) 
of the proposed AD to clarify the location of the cracking from ``the 
corners of the aft entry and aft galley doorways'' to ``the fuselage 
skin assembly and the bear strap at the corners of the aft entry and 
aft galley doorways.'' Boeing stated the unsafe condition is related to 
the fuselage skin assembly and the bear strap, and added that the word 
``doorways'' is generic and could include other structure.
    We agree with the commenter that clarification is necessary. We 
have revised the SUMMARY section and paragraphs (e) and (h) of this AD 
accordingly.

Request To Change the Inspection Paragraph Heading

    Southwest Airlines (SWA) asked that the heading of paragraph (h) of 
the proposed AD be changed from ``Repetitive Inspections'' to ``Initial 
and Repetitive Inspections'' (for Groups 2 through 8 airplanes) or that 
we remove the word ``Repetitive'' to be consistent with the heading of 
paragraph (g) of the proposed AD.
    We find that clarification is necessary. Using the term 
``repetitive inspections'' is intended to cover both the initial and 
repetitive inspections identified within the paragraph. In addition, 
the heading of paragraph (g) of this AD does not specify repetitive 
inspections because the inspection program for Group 1 airplanes is 
undefined in the service information, and the need to repeat any 
inspection would be determined on a case-by-case basis as approved by 
the FAA. Therefore, we have made no change to this AD in this regard.

Request To Clarify Service Bulletin Provisions

    SWA also asked for clarification that the notes and provisions 
identified in the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-53A1350, dated May 6, 2016, apply to paragraph (h) of the 
proposed AD. SWA stated that those notes specify that it is not 
necessary to inspect the skin and bear strap at a cutout corner 
location with an existing external repair or modification if certain 
conditions are met.
    We acknowledge the commenter's concern, and agree that the notes 
and provisions identified in the Accomplishment Instructions of Boeing 
Alert Service Bulletin 737-53A1350,

[[Page 9494]]

dated May 6, 2016, apply in this AD. No change to this AD is necessary 
in this regard.

Request To Revise Repair Method

    SWA asked that we revise paragraph (i) of the proposed AD, which 
specifies repair for cracking in accordance with Part 3 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1350, dated May 6, 2016. SWA requested that we also allow repair 
using a method approved by the FAA, in accordance with paragraph (k) of 
the proposed AD. SWA did not provide a reason for this request.
    We do not agree with the commenter's request. It is not necessary 
to specifically refer to paragraph (k) in this AD, as the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1350, dated May 6, 2016, do not include an instruction to contact 
Boeing for instructions. We will always consider a request for approval 
of an alternative method of compliance for the repair, if the request 
is accompanied by appropriate data to show that the alternative method 
would provide an acceptable level of safety. Therefore, we have made no 
change to paragraph (i) of this AD.

Additional Change From the Proposed AD

    We have changed the paragraph designation for paragraph (k)(3)(i) 
of the proposed AD to paragraph (k)(4) of this AD.

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 737-53A1350, dated May 6, 
2016. The service information describes procedures for, among other 
things, external low frequency eddy current and detailed inspections 
for cracking of the skin assembly and the bear strap, as applicable, of 
the corners of the aft entry and aft galley doorways, and repair of any 
cracking. 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 326 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................  22 work-hours x $85                $0  $1,870 per inspection  $609,620 per
                              per hour = $1,870                      cycle.                 inspection cycle.
                              per inspection cycle.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that will 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):

2017-02-05 The Boeing Company: Amendment 39-18784; Docket No. FAA-
2016-8186; Directorate Identifier 2016-NM-074-AD.

(a) Effective Date

    This AD is effective March 14, 2017.

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to all The Boeing Company Model 737-100, -
200, -200C, -300, -400, and -500 series airplanes; certificated in 
any category; as identified in Boeing Alert Service Bulletin 737-
53A1350, dated May 6, 2016.
    (2) Installation of Supplemental Type Certificate (STC) 
ST01219SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/BE866B732F6CF31086257B9700692796?OpenDocument&Highlight=st01219se) 
does not affect the ability to

[[Page 9495]]

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 reports of skin cracking found at the 
corners of the aft entry and aft galley doorways. We are issuing 
this AD to detect and correct cracking of the fuselage skin assembly 
and the bear strap at the corners of the aft entry and aft galley 
doorways, which could result in rapid decompression and consequent 
reduced structural integrity of the airplane.

(f) Compliance

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

(g) Inspections for Group 1 Airplanes

    For airplanes identified as Group 1 in Boeing Alert Service 
Bulletin 737-53A1350, dated May 6, 2016: Within 120 days after the 
effective date of this AD, inspect the airplane using a method 
approved in accordance with the procedures specified in paragraph 
(k) of this AD.

(h) Repetitive Inspections for Groups 2 Through 8 Airplanes

    For airplanes identified as Groups 2 through 8 in Boeing Alert 
Service Bulletin 737-53A1350, dated May 6, 2016: At the applicable 
time specified in paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1350, dated May 6, 2016, except as required 
by paragraph (j) of this AD, do low frequency eddy current and 
detailed inspections for cracking of the fuselage skin assembly and 
the bear strap at the aft entry and aft galley doorway corners, as 
applicable, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1350, dated May 6, 2016. Repeat 
the inspections thereafter at the applicable times specified in 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1350, dated May 6, 2016.

(i) Repair

    If any crack is found during any inspection required by 
paragraph (h) of this AD, repair before further flight, in 
accordance with Part 3 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 737-53A1350, dated May 6, 2016. 
Accomplishment of this repair terminates the repetitive inspections 
required by paragraph (h) of this AD for the repaired doorway corner 
location only.

(j) Exception to Service Information Specifications

    Where paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-53A1350, dated May 6, 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.

(k) 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 (l) 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) For service information that contains steps that are labeled 
as Required for Compliance (RC), the provisions of paragraphs 
(k)(4)(i) and (k)(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.

(l) Related Information

    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].

(m) 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 737-53A1350, dated May 6, 
2016.
    (ii) Reserved.
    (3) For service information identified in this AD, 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 January 11, 2017.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2017-01533 Filed 2-6-17; 8:45 am]
BILLING CODE 4910-13-P