
[Federal Register Volume 80, Number 56 (Tuesday, March 24, 2015)]
[Proposed Rules]
[Pages 15523-15525]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2015-06574]



[[Page 15523]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-0495; Directorate Identifier 2014-NM-172-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 
certain The Boeing Company Model 737-300, -400, and -500 series 
airplanes. This proposed AD was prompted by reports of cracking at 
certain fastener locations in the window corners of the window belt 
area. This proposed AD would require repetitive high frequency eddy 
current (HFEC) inspections for fatigue cracking in certain fastener 
locations in the window corners of the window belt area, and related 
investigative and corrective actions if necessary. This proposed AD 
would also provide an optional preventive modification that would 
terminate the repetitive inspections at the modified location. We are 
proposing this AD to detect and correct fatigue cracking around 
fastener locations that could cause multiple window corner skin cracks, 
which could result in rapid decompression and loss of structural 
integrity of the airplane.

DATES: We must receive comments on this proposed AD by May 8, 2015.

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 proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; 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-2015-
0495.

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-2015-
0495; 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 proposed AD, 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: Haytham Alaidy, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6573; fax: 425-917-6590; email: haytham.alaidy@faa.gov.

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-2015-0495; 
Directorate Identifier 2014-NM-172-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD 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 reports of cracking at certain fastener locations 
in the window corners of the window belt. At the time of the crack 
detection, the airplanes had accumulated between 37,842 and 49,050 
total flight cycles. Fatigue cracking of the fastener locations in the 
window corners of the window belt area between station (STA) 360 and 
STA 540 and between STA 727 and STA 908, left-side and right-side of 
the fuselage, at and between stringers S-11 and S-13, if not corrected, 
could result in cracking around fastener locations that could cause 
multiple window corner skin cracks, which could result in rapid 
decompression and loss of structural integrity of the airplane.

Related Service Information

    We reviewed Boeing Alert Service Bulletin 737-53A1328, dated July 
22, 2014. The service information describes procedures for inspections, 
preventative modification, and repairs of the window corners. Refer to 
this service information for information on the procedures and 
compliance times. This service information is reasonably available; see 
ADDRESSES for ways to access this service information.

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 require accomplishing the actions specified 
in the service information identified previously.
    The phrase ``related investigative actions'' is used in this 
proposed AD. ``Related investigative actions'' are follow-on actions 
that (1) are related to the primary actions, and (2) further 
investigate the nature of any condition found. Related investigative 
actions in an AD could include, for example, inspections.
    The phrase ``corrective actions'' is used in this proposed AD. 
``Corrective actions'' are actions that correct or address any 
condition found. Corrective actions in an AD could include, for 
example, repairs.

Explanation of ``RC'' Steps in Service Information

    The FAA worked in conjunction with industry, under the 
Airworthiness Directive Implementation Aviation Rulemaking Committee 
(ARC), to enhance the AD system. One enhancement was a new process for 
annotating which steps in the service information are required for 
compliance with an AD. Differentiating these steps from other tasks in 
the service

[[Page 15524]]

information is expected to improve an owner's/operator's understanding 
of crucial AD requirements and help provide consistent judgment in AD 
compliance. The steps identified as RC (required for compliance) in any 
service information identified previously have a direct effect on 
detecting, preventing, resolving, or eliminating an identified unsafe 
condition.
    Steps that are identified as RC in any service information must be 
done to comply with the proposed AD. However, steps that are not 
identified as RC are recommended. Those steps that are not identified 
as RC may be deviated from using accepted methods in accordance with 
the operator's maintenance or inspection program without obtaining 
approval of an alternative method of compliance (AMOC), provided the 
steps identified as RC can be done and the airplane can be put back in 
a serviceable condition. Any substitutions or changes to steps 
identified as RC will require approval of an AMOC.

Differences Between This Proposed AD and the Service Information

    Boeing Alert Service Bulletin 737-53A1328, dated July 22, 2014, 
specifies to contact the manufacturer for instructions on how to repair 
certain conditions, but this proposed AD would require repairing those 
conditions in one of the following ways:
     In accordance with a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by the Boeing Commercial 
Airplanes Organization Designation Authorization (ODA) whom we have 
authorized to make those findings.

Costs of Compliance

    We estimate that this proposed AD affects 142 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                            Estimated Costs: Required Actions
--------------------------------------------------------------------------------------------------------------------------------------------------------
                 Action                        Labor cost          Parts cost              Cost per product                 Cost on U.S. operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection.............................  Up to 2,312 work-hours              $0  Up to $196,520 per inspection cycle  Up to $27,905,840 per inspection
                                          x $85 per hour =                                                             cycle.
                                          $196,520 per
                                          inspection cycle.
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                        Estimated Costs: Optional Actions
----------------------------------------------------------------------------------------------------------------
                Action                        Labor cost         Parts cost             Cost per product
----------------------------------------------------------------------------------------------------------------
Preventive modification...............  108 work-hours x $85               $0  $9,180.
                                         per hour = $9,180.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary repairs that 
would be required based on the results of the proposed inspection. We 
have no way of determining the number of aircraft that might need 
repairs:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                Action                        Labor cost         Parts cost             Cost per product
----------------------------------------------------------------------------------------------------------------
Repair................................  Up to 18 work-hours x              $0  Up to $1,530 per repair.
                                         $85 per hour =
                                         $1,530 per repair.
----------------------------------------------------------------------------------------------------------------

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

    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):


[[Page 15525]]


The Boeing Company: Docket No. FAA-2015-0495; Directorate Identifier 
2014-NM-172-AD.

(a) Comments Due Date

    We must receive comments by May 8, 2015.

(b) Affected ADs

    None.

(c) Applicability

    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 737-53A1328, dated July 22, 2014.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports of fatigue cracking at certain 
fastener locations in the window corners of the window belt area. We 
are issuing this AD to detect and correct fatigue cracking around 
the fastener locations that could cause multiple window corner skin 
cracks, which could 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) Inspections

    At the applicable time specified in tables 1 and 2 of paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-53A1328, 
dated July 22, 2014, except as required by paragraph (i)(1) of this 
AD: Do external surface high frequency eddy current (HFEC) 
inspections for cracking of the skin at the 12 fastener locations at 
the upper forward and lower aft corners of each window between 
station (STA) 360 and STA 540 and between STA 727 and STA 908, left-
side and right-side of the fuselage, at and between stringers S-11 
and S-13, and all applicable related investigative and corrective 
actions, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1328, dated July 22, 2014, 
except as required by paragraph (i)(2) of this AD. Do all applicable 
related investigative and corrective actions before further flight. 
Repeat the inspections at the applicable times specified in tables 1 
and 2 of paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-53A1328, dated July 22, 2014, until the terminating 
action specified in paragraph (h) of this AD is done.

(h) Optional Preventive Modification

    Accomplishment of a preventive modification in the fastener 
locations in the window corners of the window belt area between 
station (STA) 360 and STA 540 and between STA 727 and STA 908, left-
side and right-side fuselage, at and between stringers S-11 and S-
13, terminates the inspections required by paragraph (g) of this AD 
at the modified location only. The modification, including all 
applicable related investigative and corrective actions, must be 
done in accordance with Part 3 of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1328, dated July 22, 2014, 
except as required by paragraph (i)(2) of this AD.

(i) Exceptions to the Service Bulletin Specifications

    (1) Where Boeing Alert Service Bulletin 737-53A1328, dated July 
22, 2014, 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.
    (2) Where Boeing Alert Service Bulletin 737-53A1328, dated July 
22, 2014, specifies to contact Boeing for repair instructions: 
Before further flight, repair the cracking 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, Seattle 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 (k)(1) of this AD. 
Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (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) If any service information contains steps that are 
identified as RC (Required for Compliance), those steps must be done 
to comply with this AD; any steps that are not identified as RC are 
recommended. Those steps that are not identified 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 steps identified as RC can be done 
and the airplane can be put back in a serviceable condition. Any 
substitutions or changes to steps identified as RC require approval 
of an AMOC.
    (4) An AMOC that provides an acceptable level of safety may be 
used for any repair 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, to make 
those findings. For a repair method to be approved, the repair 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 Haytham Alaidy, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-
3356; phone: 425-917-6447; fax: 425-917-6590; email: 
haytham.alaidy@faa.gov.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may view the 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.

    Issued in Renton, Washington, on March 13, 2015.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-06574 Filed 3-23-15; 8:45 am]
 BILLING CODE 4910-13-P


