
[Federal Register Volume 80, Number 83 (Thursday, April 30, 2015)]
[Rules and Regulations]
[Pages 24195-24198]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-09805]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2014-0286; Directorate Identifier 2014-NM-004-AD; 
Amendment 39-18145; AD 2015-08-09]
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 737-600 and -700 series airplanes. This AD was 
prompted by reports of cracking in the body station (STA) 727 bulkhead 
lower frame. This AD requires a detailed and open hole high frequency 
eddy current (HFEC) inspection of the left- and right-side lower frame 
webs and inner chords for cracking, and corrective actions and 
preventative modifications if necessary. This AD also provides for 
optional terminating action of the repetitive inspections, under 
certain conditions. We are issuing this AD to detect and correct 
cracking in a bulkhead lower frame web and inner chord, which could 
result in a severed frame and induced skin cracks, and could lead to 
rapid decompression of the fuselage.

DATES: This AD is effective June 4, 2015.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of June 4, 
2015.

ADDRESSES: 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 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-2014-
0286.

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-2014-
0286; 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: Alan Pohl, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6450; fax: 
425-917-6590; email: alan.pohl@faa.gov.

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 737-600 and -700 series airplanes. The NPRM published in the 
Federal Register on May 28, 2014 (79 FR 30490). The NPRM was prompted 
by reports of cracking in the body STA 727 bulkhead lower frame. The 
NPRM proposed to require a detailed and open hole high frequency eddy 
current (HFEC) inspection of the left- and right-side lower frame webs 
and inner chords for cracking, as applicable, and corrective actions 
and preventative modifications if necessary. The NPRM also proposed to 
provide for an optional terminating action for the repetitive 
inspections under certain conditions. We are issuing this AD to detect 
and correct cracking in a bulkhead lower frame web and inner chord, 
which could result in a severed frame and induced skin cracks, and 
could lead to rapid decompression of the fuselage.

Comments

    We gave the public the opportunity to participate in developing 
this AD. Boeing and United Airlines stated that they support the NPRM 
(79 FR 30490, May 28, 2014). The following presents the comments 
received on the NPRM, and the FAA's response to each comment.

Request To Clarify Modification and Repair Requirements

    Southwest Airlines (SWA) requested that we clarify whether the 
preventative modifications and repairs of the lower frame webs and 
inner chords (if

[[Page 24196]]

accomplished) must be done on both the left and right sides at the same 
time.
    SWA stated that paragraph (h) of the NPRM (79 FR 30490, May 28, 
2014) reads, ``Accomplishment of a modification or a repair, in 
accordance with Boeing Alert Service Bulletin 737-53A1325, dated 
December 3, 2013, terminates the repetitive inspections in this AD for 
the repaired or modified side only.''
    SWA stated that Boeing Alert Service Bulletin 737-53A1325, dated 
December 3, 2013, provides that for each airplane group, if a repair is 
installed on one side, a preventative modification must be installed on 
the opposing side. SWA also stated that, for airplanes with no cracks, 
a preventative modification is optional, but that the service 
information specifies that in this situation, both sides must be 
modified.
    We agree that clarification is necessary. Groups 2 and 3 airplanes 
are comprised of four airplanes on which a repair to the left side was 
installed prior to the issuance of Boeing Alert Service Bulletin 737-
53A1325, dated December 3, 2013. Therefore, SWA's comments are 
primarily for Group 1 airplanes.
    As specified in Boeing Alert Service Bulletin 737-53A1325, dated 
December 3, 2013, if a crack is found on one side, then that side must 
be repaired and the preventative modification concurrently installed on 
the other side, even if that other side is not cracked. We also agree 
that if no cracking is found on either side and the operator chooses to 
install the preventative modification, then both sides must be 
modified, as specified in paragraph 3.B., Part 2, Step 2 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1325, dated December 3, 2013. Installing the preventative 
modification terminates the repetitive inspections. We have removed the 
wording ``for the repaired or modified side only'' from paragraph (h) 
of this AD.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that accomplishing the supplemental 
type certificate (STC) ST00830SE (http://rgl.faa.gov/
Regulatory_and_Guidance_Library/rgstc.nsf/0/
932b6080caa1856e86257d6c005c5a37/$FILE/ST00830SE.pdf) does not affect 
the actions specified in the NPRM (79 FR 30490, May 28, 2014).
    We concur with the commenter. We have redesignated paragraph (c) of 
the NPRM (79 FR 30490, May 28, 2014) as paragraph (c)(1) and added new 
paragraph (c)(2) to this AD to state that installation of STC ST00830SE 
(http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/
932b6080caa1856e86257d6c005c5a37/$FILE/ST00830SE.pdf) does not affect 
the ability to accomplish the actions required by this AD. Therefore, 
for airplanes on which STC ST00830SE 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.

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:
     [Agr]re consistent with the intent that was proposed in 
the NPRM (79 FR 30490, May 28, 2014) for correcting the unsafe 
condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM (79 FR 30490, May 28, 2014).
    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 737-53A1325, dated 
December 3, 2013. The service information describes procedures for a 
detailed and open hole HFEC inspection of the left- and right-side 
lower frame webs and inner chords for cracking, and corrective actions 
and preventative modifications if necessary. The service information 
also provides for an optional terminating action of the repetitive 
inspections, under certain conditions. This service information is 
reasonably available at http://www.regulations.gov by searching for and 
locating Docket No. FAA-2014-0286. Or see ADDRESSES for other ways to 
access this service information.

Costs of Compliance

    We estimate that this AD affects 489 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                    Cost per       Cost on U.S.
               Action                        Labor cost           Parts cost        product         operators
----------------------------------------------------------------------------------------------------------------
Inspections.........................  37 work-hours x $85 per              $0           $3,145       $1,537,905
                                       hour = $3,145.
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    We estimate the following costs to do any necessary repairs that 
would be required based on the results of the inspections. We have no 
way of determining the number of aircraft that might need these 
repairs:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Repair (per side).............................  11 work-hours x $85 per hour =            $2,820          $3,755
                                                 $935.
Modification..................................  17 work-hours x $85 per hour =             1,132           2,577
                                                 $1,445.
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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

[[Page 24197]]

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):

2015-08-09 The Boeing Company: Amendment 39-18145; Docket No. FAA-
2014-0286; Directorate Identifier 2014-NM-004-AD.

(a) Effective Date

    This AD is effective June 4, 2015.

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to The Boeing Company Model 737-600 and -700 
series airplanes, certificated in any category, as identified in 
Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013.
    (2) Installation of Supplemental Type Certificate (STC) 
ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/
rgstc.nsf/0/932b6080caa1856e86257d6c005c5a37/$FILE/ST00830SE.pdf) 
does not affect the ability to accomplish the actions required by 
this AD. Therefore, for airplanes on which STC ST00830SE 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 cracking in the body station 
727 bulkhead lower frame. We are issuing this AD to detect and 
correct cracking in a bulkhead lower frame web and inner chord, 
which could result in a severed framed and induced skin cracks, and 
could lead to rapid decompression of the fuselage.

(f) Compliance

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

(g) Inspections

    At the applicable times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1325, dated 
December 3, 2013, except as provided by paragraph (i)(1) of this AD: 
Do a detailed and open hole high frequency eddy current (HFEC) 
inspection of the left- and right-side lower frame webs and inner 
chords for cracking, as applicable, and do all applicable corrective 
actions and preventative modifications, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1325, dated December 3, 2013, except as required by paragraph 
(i)(2) of this AD. Repeat the applicable inspections required by 
this paragraph thereafter at the applicable intervals specified in 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1325, dated December 3, 2013. Do all applicable corrective 
actions and preventative modifications before further flight.

(h) Terminating Action

    Accomplishment of a modification or a repair, in accordance with 
Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013, 
terminates the repetitive inspections required by this AD.

(i) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Service Bulletin 737-53A1325, dated 
December 3, 2013, 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 737-53A1325, dated 
December 3, 2013, specifies to contact Boeing for appropriate 
action: Before further flight, accomplish the corresponding action 
using a method approved in accordance with the procedures specified 
in paragraph (k) of this AD.

(j) Post-Repair Inspections

    The post-repair inspections specified in tables 4, 5, and 6 of 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1325, dated December 3, 2013, are not required by this AD.

    Note 1 to paragraph (j) of this AD: The damage tolerance 
inspections specified in tables 4, 5, and 6 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1325, dated 
December 3, 2013, may be used in support of compliance with Section 
121.1109(c)(2) or 129.109(b)(2) of the Federal Aviation Regulations 
(14 CFR 121.1109(c)(2) or 14 CFR 129.109(b)(2)). The corresponding 
actions specified in the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-53A1325, dated December 3, 2013, are not 
required by this AD.

(k) 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 (l) 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) 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.

(l) Related Information

    For more information about this AD, contact Alan Pohl, Aerospace 
Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; 
phone: 425-917-6450; fax: 425-917-6590; email: alan.pohl@faa.gov.

(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

[[Page 24198]]

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 737-53A1325, dated December 3, 
2013.
    (ii) Reserved.
    (3) For Boeing 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.
    (4) 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.
    (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 April 13, 2015.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-09805 Filed 4-29-15; 8:45 am]
BILLING CODE 4910-13-P


