[Federal Register Volume 83, Number 53 (Monday, March 19, 2018)]
[Rules and Regulations]
[Pages 11871-11873]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-05016]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0903; Product Identifier 2017-NM-074-AD; Amendment 
39-19225; AD 2018-06-05]
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 certain 
The Boeing Company Model 737-300 and -500 series airplanes. This AD was 
prompted by a report indicating that fatigue cracks were found in the 
lower wing skin of an airplane with winglets installed. This AD 
requires repetitive inspections for cracking of the lower wing skin, 
and repair if necessary. We are issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective April 23, 2018.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of April 23, 
2018.

ADDRESSES: For service information identified in this final rule, 
contact Aviation Partners Boeing, 2811 South 102nd St., Suite 200, 
Seattle, WA 98168; phone: 1-206-830-7699; fax: 1-206-767-3355; email: 
[email protected]; internet: http://www.aviationpartnersboeing.com. You may view this service information 
at the FAA, Transport Standards Branch, 2200 South 216th St., Des 
Moines, WA. For information on the availability of this material at the 
FAA, call 206-231-3195. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-
0903.

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-2017-
0903; 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 final rule, 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: Lu Lu, Aerospace Engineer, Airframe 
Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 
98198; phone and fax: 206-231-3525; 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 and -500 series airplanes. The NPRM published in the 
Federal Register on October 6, 2017 (82 FR 46725). The NPRM was 
prompted by a report indicating that fatigue cracks were found in the 
lower wing skin of an airplane with winglets installed. The NPRM 
proposed to require repetitive inspections for cracking of the lower 
wing skin, and repair if necessary.
    We are issuing this AD to detect and correct fatigue cracking of 
the lower wing skin common to the runout of stringer L-5. Such cracking 
could grow and result in loss of structural integrity of the wing, and 
consequent reduced, or complete loss of, controllability of the 
airplane.

Comments

    We gave the public the opportunity to participate in developing 
this final rule. The following presents the comments received on the 
NPRM and the FAA's response to each comment. Aviation Partners Boeing 
concurred with the proposed AD.

Request for Manufacturer To Share Expense

    One commenter, Mary Lou Allen, requested that the airplane 
manufacturer share in the expense with the airplane's purchaser or 
owner, because of the high costs associated with supplemental type 
certificates. We infer that the commenter wants manufacturers to be 
required to help pay for compliance with the proposed AD.
    We do not agree to this request. We provide estimates of the cost 
on U.S. operators for AD compliance, but do not determine who is 
responsible for payment. We are aware that airplane manufacturers and 
modifiers often have warranty agreements with owners and operators to 
cover some or all of the costs of modifications or repairs, but we do 
not participate in these agreements. We have not changed this AD in 
this regard.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this final rule as proposed, except for 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.

Related Service Information Under 1 CFR Part 51

    We reviewed Aviation Partners Boeing Service Bulletin AP737C-57-
002, dated April 5, 2017. The service information describes procedures 
for repetitive inspections for cracking of the lower wing skin, and 
repair if necessary. 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.

[[Page 11872]]

Costs of Compliance

    We estimate that this AD affects 93 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
----------------------------------------------------------------------------------------------------------------
Repetitive inspection............  1 work-hour x $85                $0  $85 per inspection   Up to $7,905 per
                                    per hour = $85 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.
    This AD is issued in accordance with authority delegated by the 
Executive Director, Aircraft Certification Service, as authorized by 
FAA Order 8000.51C. In accordance with that order, issuance of ADs is 
normally a function of the Compliance and Airworthiness Division, but 
during this transition period, the Executive Director has delegated the 
authority to issue ADs applicable to transport category airplanes to 
the Director of the System Oversight Division.

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):

2018-06-05 The Boeing Company: Amendment 39-19225; Docket No. FAA-
2017-0903; Product Identifier 2017-NM-074-AD.

(a) Effective Date

    This AD is effective April 23, 2018.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 737-300 and -500 
series airplanes, certificated in any category, with blended winglet 
kits installed in accordance with Supplemental Type Certificate 
(STC) ST01219SE.

(d) Subject

    Air Transport Association (ATA) of America Code 57, Wings.

(e) Unsafe Condition

    This AD was prompted by a report indicating that fatigue cracks 
were found in the lower wing skin at stringer L-5 of a Boeing Model 
737-300 airplane with winglets installed. We are issuing this AD to 
detect and correct fatigue cracking of the lower wing skin common to 
the runout of stringer L-5. Such cracking could grow and result in 
loss of structural integrity of the wing, and consequent reduced, or 
complete loss of, controllability of the airplane.

(f) Compliance

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

(g) Repetitive Inspection

    Within 18 months after the effective date of this AD: Do a 
detailed inspection for cracking of the lower wing skin external 
surface at the stringer L-5 location on the left and right wings, in 
accordance with the Accomplishment Instructions of Aviation Partners 
Boeing Service Bulletin AP737C-57-002, dated April 5, 2017. Repeat 
the inspection thereafter at intervals not to exceed 6,000 flight 
cycles or 9,000 flight hours, whichever occurs first.

(h) Repair

    If any crack is found during any inspection required by 
paragraph (g) of this AD, repair before further flight using a 
method approved in accordance with the procedures specified in 
paragraph (i) of this AD. Although Aviation Partners Boeing Service 
Bulletin AP737C-57-002, dated April 5, 2017, 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.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO Branch, 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 certification office, 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

[[Page 11873]]

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 Branch, 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 (h) 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 Lu Lu, Aerospace 
Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 
216th St., Des Moines, WA 98198; phone and fax: 206-231-3525; 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) Aviation Partners Boeing Service Bulletin AP737C-57-002, 
dated April 5, 2017.
    (ii) Reserved.
    (3) For service information identified in this AD, contact 
Aviation Partners Boeing, 2811 South 102nd St., Suite 200, Seattle, 
WA 98168; phone: 1-206-830-7699; fax: 1-206-767-3355; email: 
[email protected]; internet: http://www.aviationpartnersboeing.com.
    (4) You may view this service information at the FAA, Transport 
Standards Branch, 2200 South 216th St., Des Moines, WA. For 
information on the availability of this material at the FAA, call 
206-231-3195.
    (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 March 5, 2018.
Michael Kaszycki,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2018-05016 Filed 3-16-18; 8:45 am]
 BILLING CODE 4910-13-P