
[Federal Register Volume 78, Number 80 (Thursday, April 25, 2013)]
[Rules and Regulations]
[Pages 24338-24340]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-08996]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0935; Directorate Identifier 2011-NM-256-AD; 
Amendment 39-17428; AD 2013-08-11]
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 737-900 and -900ER series airplanes. This AD 
was prompted by reports of early fatigue cracks at chem-mill areas on 
the crown skin panels. This AD requires repetitive inspections for 
cracking of the fuselage skin along chem-mill steps at certain crown 
skin and shear wrinkle areas, and repair if necessary. We are issuing 
this AD to detect and correct fatigue cracking of the skin panel at the 
specified chem-mill step locations, which could result in rapid 
decompression of the airplane.

DATES: This AD is effective May 30, 2013.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of May 30, 2013.

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 review copies of the referenced service 
information at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue SW., Renton, Washington. For information on the availability of 
this material at the FAA, call 425-227-1221.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; 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 Document 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: Wayne Lockett, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: (425) 917-6447; 
fax: (425) 917-6590; email: Wayne.Lockett@faa.gov.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM published in the Federal Register on September 18, 2012 (77 
FR 57539). That NPRM proposed to require repetitive inspections for 
cracking of the fuselage skin along chem-mill steps at certain crown 
skin and shear wrinkle areas, and repair if necessary.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
(77 FR 57539, September 18, 2012) and the FAA's response to each 
comment.

Request to Revise Federal Aviation Regulations Citations

    Boeing stated that references to section 129.109(c)(2) of the 
Federal Aviation Regulations (14 CFR 129.109(c)(2)) are incorrect, 
since that paragraph does not exist in the current revision of the 
Federal Aviation Regulations and that the correct paragraph reference 
is section 129.109(b)(2). Boeing noted that this error occurred in the 
second paragraph of the ``Differences Between the Proposed AD and the 
Service Information'' section, and in Note 1 to paragraph (l) of the 
proposed AD (77 FR 57539, September 18, 2012).
    We agree that the specified references are incorrect. We agree that 
the citation in the proposed AD (77 FR 57539, September 18, 2012) is 
inaccurate, but since that section of the preamble does not reappear in 
this AD, no corresponding change to this AD is necessary. We have 
corrected the citation in Note 1 to paragraph (l) of this AD.

Winglet Supplemental Type Certificate (STC) Comment

    Aviation Partners Boeing stated that the installation of winglets 
per STC ST00830SE (http://rgl.faa.gov/Regulatory--and--Guidance--
Library/

[[Page 24339]]

rgstc.nsf/0/
408E012E008616A7862578880060456C?OpenDocument&Highlight=st00830se) does 
not affect the actions specified in the NPRM (77 FR 57539, September 
18, 2012).
    We concur. We have added paragraph (c)(2) to this AD to state that 
installation of STC ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/408E012E008616A7862578880060456C?OpenDocument&Highlight=st00830se) 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 
the AD with the changes described previously and minor editorial 
changes. We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM (77 FR 57539, September 18, 2012) for correcting the unsafe 
condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM (77 FR 57539, September 18, 2012).
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of the AD.

Costs of Compliance

    We estimate that this AD affects 58 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
----------------------------------------------------------------------------------------------------------------
Inspection of chem-mill step      31 work-hours x     None..............  $2,635, per         $152,830, per
 locations.                        $85 per hour =                          inspection cycle.   inspection cycle.
                                   $2,635, 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 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.

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 
irective (AD):

2013-08-11 The Boeing Company: Amendment 39-17428; Docket No. FAA-
2012-0935; Directorate Identifier 2011-NM-256-AD.

(a) Effective Date

    This AD is effective May 30, 2013.

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to The Boeing Company Model 737-900 and -
900ER series airplanes, certificated in any category, as identified 
in Boeing Service Bulletin 737-53-1312, dated October 21, 2011, as 
revised by Boeing Service Bulletin 737-53-1312, Revision 1, dated 
March 14, 2012.
    (2) Installation of Supplemental Type Certificate (STC) 
ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/408E012E008616A7862578880060456C?OpenDocument&Highlight=st00830se) 
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

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 53; Fuselage.

(e) Unsafe Condition

    This AD was prompted by reports of early fatigue cracks at chem-
mill areas on the crown skin panels. We are issuing this AD to 
detect and correct fatigue cracking of the skin panel at the 
specified chem-mill step locations, which could result in rapid 
decompression of the airplane.

(f) Compliance

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

(g) Inspections of Crown Skin Areas

    At the applicable time specified in paragraph 1.E., 
``Compliance,'' of Boeing Service Bulletin 737-53-1312, dated 
October

[[Page 24340]]

21, 2011, as revised by Boeing Service Bulletin 737-53-1312, 
Revision 1, dated March 14, 2012, except as required by paragraph 
(k) of this AD: Do an external detailed inspection and an external 
nondestructive inspection (a medium frequency eddy current (MFEC), 
magneto optic imager (MOI), C-scan, or ultrasonic phased array 
(UTPA) inspection) for cracking in the fuselage skin along the chem-
mill steps at certain locations specified in, and in accordance 
with, the Accomplishment Instructions of Boeing Service Bulletin 
737-53-1312, dated October 21, 2011, as revised by Boeing Service 
Bulletin 737-53-1312, Revision 1, dated March 14, 2012. Repeat the 
inspections thereafter at the applicable times specified in 
paragraph 1.E., ``Compliance,'' of Boeing Service Bulletin 737-53-
1312, dated October 21, 2011, as revised by Boeing Service Bulletin 
737-53-1312, Revision 1, dated March 14, 2012.

(h) Inspections of Shear Wrinkle Areas

    For Group 1 airplanes as identified in Boeing Service Bulletin 
737-53-1312, dated October 21, 2011, as revised by Boeing Service 
Bulletin 737-53-1312, Revision 1, dated March 14, 2012: At the 
applicable time specified in paragraph 1.E., ``Compliance,'' of 
Boeing Service Bulletin 737-53-1312, dated October 21, 2011, as 
revised by Boeing Service Bulletin 737-53-1312, Revision 1, dated 
March 14, 2012, except as required by paragraph (k) of this AD, do 
an external detailed inspection and an external nondestructive 
inspection (MFEC, MOI, C-scan, or UTPA) for cracking in the fuselage 
skin along the chem-mill steps at certain shear wrinkle locations 
specified in, and in accordance with, the Accomplishment 
Instructions of Boeing Service Bulletin 737-53-1312, dated October 
21, 2011, as revised by Boeing Service Bulletin 737-53-1312, 
Revision 1, dated March 14, 2012. Repeat the inspections thereafter 
at the applicable times specified in paragraph 1.E., ``Compliance,'' 
of Boeing Service Bulletin 737-53-1312, dated October 21, 2011, as 
revised by Boeing Service Bulletin 737-53-1312, Revision 1, dated 
March 14, 2012.

(i) Repair

    If any cracking is found during any inspection required by 
either paragraph (g) or (h) of this AD, before further flight, 
repair the cracking using a method approved in accordance with the 
procedures specified in paragraph (m) of this AD. Accomplishing the 
repair approved in accordance with the procedures specified in 
paragraph (m) of this AD terminates the repetitive inspection 
requirement for that area under the repair only.

(j) Optional Terminating Modification

    Modification of an inspection area specified in paragraph (g) of 
this AD, including doing an external detailed inspection and an 
external nondestructive inspection (MFEC, MOI, C-scan, or UTPA) for 
cracking of the area to be modified, and a high frequency eddy 
current inspection of all existing holes for cracking as applicable, 
in accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 737-53-1312, dated October 21, 2011, as revised by Boeing 
Service Bulletin 737-53-1312, Revision 1, dated March 14, 2012, 
terminates the repetitive inspections required by paragraph (g) of 
this AD for that modified area only. If any cracking is found during 
any inspection described by this paragraph, before further flight, 
repair the cracking using a method approved in accordance with the 
procedures specified in paragraph (m) of this AD.

(k) Service Bulletin Exception

    Boeing Service Bulletin 737-53-1312, dated October 21, 2011, as 
revised by Boeing Service Bulletin 737-53-1312, Revision 1, dated 
March 14, 2012, specifies compliance times ``after the original 
issue date of this service bulletin.'' However, this AD requires 
compliance within the specified compliance times ``after the 
effective date of this AD.''

(l) Post-Modification Inspections

    The post-modification inspections specified in Tables 3 and 4 of 
paragraph 1.E., ``Compliance,'' of Boeing Service Bulletin 737-53-
1312, dated October 21, 2011, as revised by Boeing Service Bulletin 
737-53-1312, Revision 1, dated March 14, 2012, are not required by 
this AD.

    Note 1 to paragraph (l) of this AD: The damage tolerance 
inspections specified in Tables 3 and 4 of paragraph 1.E., 
``Compliance,'' of Boeing Service Bulletin 737-53-1312, dated 
October 21, 2011, as revised by Boeing Service Bulletin 737-53-1312, 
Revision 1, dated March 14, 2012, 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 actions specified in Part 5 of the 
Accomplishment Instructions and corresponding figures of Boeing 
Service Bulletin 737-53-1312, dated October 21, 2011, as revised by 
Boeing Service Bulletin 737-53-1312, Revision 1, dated March 14, 
2012, are not required by this AD.

(m) 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 the Related Information 
section 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.

(n) Related Information

    For more information about this AD, contact Wayne Lockett, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; 
phone: (425) 917-6447; fax: (425) 917-6590; email: 
Wayne.Lockett@faa.gov.

(o) 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) Boeing Service Bulletin 737-53-1312, dated October 21, 2011.
    (ii) Boeing Service Bulletin 737-53-1312, Revision 1, dated 
March 14, 2012.
    (3) 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.
    (4) You may view this service information at FAA, Transport 
Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. 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 4, 2013.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-08996 Filed 4-24-13; 8:45 am]
BILLING CODE 4910-13-P


