[Federal Register Volume 83, Number 28 (Friday, February 9, 2018)]
[Proposed Rules]
[Pages 5743-5746]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-02193]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0074; Product Identifier 2017-NM-148-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 
series airplanes. This proposed AD was prompted by reports of cracks 
found in the rear spar web and lower chord on the left and right wings. 
This proposed AD would require repetitive detailed inspections for 
cracking of the rear spar web and lower chord, and applicable on-
condition actions. We are proposing this AD to address the unsafe 
condition on these products.

DATES: We must receive comments on this proposed AD by March 26, 2018.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, 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 
Standards Branch, 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-2018-0074.

[[Page 5744]]

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-2018-
0074; 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 NPRM, the regulatory evaluation, any comments received, 
and other information. The street address for the Docket Office (phone: 
800-647-5527) is in the ADDRESSES section. Comments will be available 
in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Payman Soltani, Aerospace Engineer, 
Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount 
Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5313; fax: 562-627-
5210; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2018-0074; 
Product Identifier 2017-NM-148-AD'' at the beginning of your comments. 
We specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this NPRM. We will consider all 
comments received by the closing date and may amend this NPRM because 
of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    We have received a report indicating that cracks were found at 
fastener holes in the rear spar web and lower chord on the left and 
right wings between wing buttock line (WBL) 93 and WBL 146 on ten 
airplanes. The cracks were found on airplanes with total flight cycles 
between 46,190 and 55,633. Cracks in the rear spar web were reported on 
six airplanes. Cracks in the lower chord of the rear spar were reported 
on four airplanes. On one airplane, cracks were found at multiple 
locations in the rear spar web and in the lower chord. The largest 
reported cracks were 0.059 inch in the upper rear spar web, 0.045 inch 
in the lower rear spar web, and 0.063 inch in the lower chord. This 
condition, if not corrected, could lead to the inability of a principal 
structural element to sustain required flight load, which could 
adversely affect the structural integrity of the airplane.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Requirements Bulletin 737-57A1337 RB, 
dated September 14, 2017. The service information describes procedures 
for repetitive detailed or surface High Frequency Eddy Current (HFEC) 
inspections for cracking of the rear spar web and lower chord, and 
applicable on-condition actions. 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.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    For Group 2 airplanes (line numbers 292 through 3132), this 
proposed AD would require accomplishment of the actions identified in 
the Boeing Alert Requirements Bulletin 737-57A1337 RB, dated September 
14, 2017, described previously, except for any differences identified 
as exceptions in the regulatory text of this proposed AD. For 
information on the procedures and compliance times, see this service 
information at http://www.regulations.gov by searching for and locating 
Docket No. FAA-2018-0074.
    Group 1 airplanes (line numbers 1 through 291) have a limit of 
validity (LOV) of 34,000 total flight cycles, and the actions specified 
in Boeing Alert Requirements Bulletin 737-57A1337 RB, dated September 
14, 2017, would be required at a compliance time occurring after that 
LOV. Although operation of an airplane beyond its LOV is prohibited by 
14 CFR 121.1115 and 129.115, this NPRM would include those airplanes so 
they are tracked in the event the LOV is extended in the future.

Explanation of ``RB'' (Requirements Bulletin)

    The FAA has worked in conjunction with industry, under the 
Airworthiness Directives Implementation Aviation Rulemaking Committee 
(AD ARC), to enhance the AD system. One enhancement is a process for 
annotating which steps in the service information are ``required for 
compliance'' (RC) with an AD. Boeing has implemented this RC concept 
into Boeing service bulletins.
    In an effort to further improve the quality and flow time for AD-
related Boeing service information, a joint process improvement 
initiative was worked between the FAA and Boeing. The initiative 
resulted in the development of a new process in which the service 
information more clearly identifies the actions needed to address the 
unsafe condition in the ``Accomplishment Instructions.'' The new 
process results in a Boeing Requirements Bulletin (RB), which contains 
only the actions needed to address the unsafe condition (i.e., only RC 
actions).

Costs of Compliance

    We estimate that this proposed AD affects 160 airplanes of U.S. 
registry. We estimate the following costs to comply with this proposed 
AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                    Labor cost         Parts cost      Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Inspections.....................  Up to 22 work-hours              $0   Up to $1,870 per     Up to $299,200 per
                                   x $85 per hour =                      inspection cycle.    inspection cycle.
                                   up to $1,870 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 proposed 
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

[[Page 5745]]

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 proposed 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

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the 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.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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):

The Boeing Company: Docket No. FAA-2018-0074; Product Identifier 
2017-NM-148-AD.

(a) Comments Due Date

    We must receive comments by March 26, 2018.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all The Boeing Company Model 737-100, -200, -
200C, -300, -400, and -500 series airplanes, certificated in any 
category.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports of cracks found in the rear spar 
web and lower chord on the left and right wings. We are issuing this 
AD to detect and correct cracks in the rear spar of the left and 
right wing between wing buttock line (WBL) 91 and WBL 155, which 
could lead to the inability of a principal structural element to 
sustain required flight load and adversely affect the structural 
integrity of the airplane.

(f) Compliance

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

(g) Required Actions for Group 1 Airplanes

    For airplanes identified in Group 1 in Boeing Alert Requirements 
Bulletin 737-57A1337 RB, dated September 14, 2017: Within 120 days 
after the effective date of this AD, inspect the airplane and do all 
applicable corrective actions using a method approved in accordance 
with the procedures specified in paragraph (j) of this AD.

(h) Required Actions for Group 2 Airplanes

    For airplanes identified as Group 2 in Boeing Alert Requirements 
Bulletin 737-57A1337 RB, dated September 14, 2017: Except as 
required by paragraph (i) of this AD, at the applicable times 
specified in the ``Compliance'' paragraph of Boeing Alert 
Requirements Bulletin 737-57A1337 RB, dated September 14, 2017, do 
all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
737-57A1337 RB, dated September 14, 2017.

    Note 1 to paragraph (h) of this AD: Guidance for accomplishing 
the actions required by this AD is included in Boeing Alert Service 
Bulletin 737-57A1337, dated September 14, 2017, which is referred to 
in Boeing Alert Requirements Bulletin 737-57A1337 RB, dated 
September 14, 2017.

(i) Exceptions to Service Information Specifications

    (1) For purposes of determining compliance with the requirements 
of this AD: Where Boeing Alert Requirements Bulletin 737-57A1337 RB, 
dated September 14, 2017, uses the phrase ``the original issue date 
of Requirements Bulletin 737-57A1337 RB,'' this AD requires using 
``the effective date of this AD.''
    (2) Where Boeing Alert Requirements Bulletin 737-57A1337 RB, 
dated September 14, 2017, specifies contacting Boeing, this AD 
requires repair using a method approved in accordance with the 
procedures specified in paragraph (j) of this AD.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles 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 (k)(1) 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 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.

(k) Related Information

    (1) For more information about this AD, contact Payman Soltani, 
Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5313; fax: 562-627-5210; email: [email protected].
    (2) 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-
5600; telephone 562-797-1717; internet https://www.myboeingfleet.com. You may view this referenced service 
information at the FAA, Transport Standards Branch, 1601 Lind Avenue 
SW, Renton, WA. For information on the availability of this material 
at the FAA, call 425-227-1221.


[[Page 5746]]


    Issued in Renton, Washington, on January 26, 2018.
Michael Kaszycki,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2018-02193 Filed 2-8-18; 8:45 am]
 BILLING CODE 4910-13-P