[Federal Register Volume 84, Number 77 (Monday, April 22, 2019)]
[Proposed Rules]
[Pages 16628-16630]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-07937]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0249; Product Identifier 2019-NM-010-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 supersede Airworthiness Directive (AD) 2017-25-
12, which applies to all The Boeing Company Model 737-100, -200, -200C, 
-300, -400, and -500 series airplanes. AD 2017-25-12 requires 
repetitive inspections for cracking of the webs of the stub beams at 
certain fuselage stations, and applicable on-condition actions. Since 
we issued AD 2017-25-12, we have received reports of horizontal 
cracking in the station (STA) 685 stub beam at the inboard end of the 
upper chord and the outboard end of the lower chord. AD 2017-25-12 did 
not require an inspection of the area where the horizontal cracks were 
found. This proposed AD would require repetitive inspections at certain 
fuselage stations for cracking of the stub beams, 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 June 6, 2019.

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 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-2019-0249.

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-2019-
0249; or in person at Docket Operations 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 Docket Operations (phone: 800-647-
5527) is in the ADDRESSES section. Comments will be available in the AD 
docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Galib Abumeri, Aerospace Engineer, 
Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount 
Boulevard, Lakewood, CA 90712 4137; phone: 562-627-5324; 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-2019-0249; 
Product Identifier 2019-NM-010-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 issued AD 2017-25-12, Amendment 39-19126 (82 FR 59967, December 
18, 2017) (``AD 2017-25-12''), for all The Boeing Company Model 737-
100, -200, -200C, -300, -400, and -500 series airplanes. AD 2017-25-12 
requires repetitive inspections for cracking of the webs of the stub 
beams at certain fuselage stations, and applicable on-condition 
actions. AD 2017-25-12 resulted from reports of cracking in the webs of 
the stub beams at certain fuselage stations. These cracks are a result 
of fatigue caused by cyclical loading from pressurization, wing loads, 
and landing loads. We issued AD 2017-25-12 to address cracking in the 
webs of the stub beams at certain fuselage stations, which, if not 
corrected, could result in the loss of structural integrity of the 
airframe during flight, collapse of the main landing gear, and failure 
of the pressure deck.

Actions Since AD 2017-25-12 Was Issued

    Since we issued AD 2017-25-12, we have received reports of 
horizontal cracking in the STA 685 stub beam at the inboard end of the 
upper chord and the outboard end of the lower chord. These cracks were 
caused by overload of the stub beams, leading to ductile separation. 
Cracks have occurred in the stub beam webs at STA 685 on the left and 
right sides of airplanes having total flight cycles ranging between 
11,167 and 45,892 at the time of the crack finding. If left undetected, 
such cracking could lead to the loss of structural integrity of the 
airframe during flight, collapse of the main landing gear, and possible 
failure of the pressure deck. AD

[[Page 16629]]

2017-25-12 did not require an inspection of the area where the 
horizontal cracks were found.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Service Bulletin 737-53A1364, Revision 1, 
dated October 25, 2018. The service information describes procedures 
for inspections at certain fuselage stations for cracking of the stub 
beams (which includes the web, upper chord, and lower chord), and 
applicable on-condition actions. The inspections include high frequency 
eddy current (HFEC) and detailed inspections for cracking of the 
fuselage stub beam webs below the passenger floor at STA 685, STA 695, 
and STA 706, general visual inspections for any existing repair in the 
STA 685 and STA 706 stub beam webs and HFEC inspections for cracking in 
repaired areas. 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

    This proposed AD would retain none of the requirements of AD 2017-
25-12. This proposed AD would require accomplishment of the actions 
identified as ``RC'' (required for compliance) in the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1364, Revision 1, 
dated October 25, 2018, 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-2019-0249.

Costs of Compliance

    We estimate that this proposed AD affects 171 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 13 work-hours              $0  $1,105 per           $188,955 per
                                    x $85 per hour =                     inspection cycle.    inspection cycle.
                                    $1,105 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 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 and associated appliances to the 
Director of the System Oversight Division.

Regulatory Findings

    We have 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 that the 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 removing Airworthiness Directive (AD) 
AD 2017-25-12, Amendment 39-19126 (82 FR 59967, December 18, 2017), and 
adding the following new AD:

The Boeing Company: Docket No. FAA-2019-0249; Product Identifier 
2019-NM-010AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by June 6, 2019.

(b) Affected ADs

    This AD replaces 2017-25-12, Amendment 39-19126 (82 FR 59967, 
December 18, 2017) (``AD 2017-25-12'').

(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.

[[Page 16630]]

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by reports of cracking in the webs of the 
stub beams at certain fuselage stations, and cracking of the stub 
beam at fuselage station 685 at the inboard end of the upper chord 
and the outboard end of the lower chord. We are issuing this AD to 
address such cracking, which, if not corrected, could result in the 
loss of structural integrity of the airframe during flight, collapse 
of the main landing gear, and failure of the pressure deck.

(f) Compliance

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

(g) Required Actions for Group 1 Airplanes

    For airplanes identified as Group 1 in Boeing Alert Service 
Bulletin 737-53A1364, Revision 1, dated October 25, 2018, within 120 
days after the effective date of this AD, inspect the stub beams and 
stub beam webs for any cracking or existing repairs, and do all 
applicable on-condition actions, using a method approved in 
accordance with the procedures specified in paragraph (j) of this 
AD.

(h) Required Actions for Groups 2 Through 6 Airplanes

    Except as specified by paragraph (i) of this AD: At the 
applicable times specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-53A1364, Revision 1, dated October 
25, 2018, do all applicable actions identified as ``RC'' (required 
for compliance) in, and in accordance with, the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1364, Revision 
1, dated October 25, 2018.

(i) Exceptions to Service Information Specifications

    (1) For purposes of determining compliance with the requirements 
of this AD: Where Boeing Alert Service Bulletin 737-53A1364, 
Revision 1, dated October 25, 2018, uses the phrase ``the revision 1 
issue date of this service bulletin,'' this AD requires using ``the 
effective date of this AD,'' except where Boeing Alert Service 
Bulletin 737-53A1364, Revision 1, dated October 25, 2018, uses the 
phrase ``the original issue date of this service bulletin'' in a 
note or flag note.
    (2) Where Boeing Alert Service Bulletin 737-53A1364, Revision 1, 
dated October 25, 2018, specifies contacting Boeing for repair 
instructions: This AD requires doing the repair before further 
flight 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, FAA, 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 specified by paragraph (i) of this AD: For service 
information that contains steps that are labeled as Required for 
Compliance (RC), the provisions of paragraphs (j)(4)(i) and 
(j)(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.

(k) Related Information

    (1) For more information about this AD, contact Galib Abumeri, 
Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5324; 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, 2200 South 216th 
St., Des Moines, WA. For information on the availability of this 
material at the FAA, call 206-231-3195.

    Issued in Des Moines, Washington, on April 10, 2019.
Michael J. Kaszycki,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2019-07937 Filed 4-19-19; 8:45 am]
 BILLING CODE 4910-13-P


