[Federal Register Volume 72, Number 50 (Thursday, March 15, 2007)]
[Rules and Regulations]
[Pages 12068-12070]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-4540]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24369; Directorate Identifier 2006-NM-001-AD; 
Amendment 39-14990; AD 2007-06-09]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-600, -700, -700C, and 
-800 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD), which applies to certain Boeing Model 737-600, -700, -700C, and -
800 series airplanes. That AD currently requires replacing the point 
``D'' splice fitting between windows number 1 and 2 with a new splice 
fitting; performing an eddy current inspection for cracking of the 
holes in the structure common to the new splice fitting, including 
doing any related investigative actions; and performing corrective 
actions if necessary. This new AD adds repetitive inspections for 
cracking of the skin just below each splice fitting, and related 
corrective actions if necessary. This AD results from full-scale 
fuselage fatigue testing on the splice fitting that failed prior to the 
design objective on Boeing Model 737-800 series airplanes, and a report 
of a cracked splice fitting on an operational airplane. We are issuing 
this AD to prevent cracking of the existing fitting, which may result 
in cracking through the skin and consequent decompression of the flight 
deck.

DATES: This AD becomes effective April 19, 2007.
    The incorporation by reference of Boeing Alert Service Bulletin 
737-53A1222, Revision 3, dated January 3, 2007, as listed in the 
regulations, is approved by the Director of the Federal Register as of 
April 19, 2007.
    On December 21, 2005 (70 FR 72595, December 6, 2005), the Director 
of the Federal Register approved the incorporation by reference of 
Boeing Alert Service Bulletin 737-53A1222, Revision 2, dated October 
20, 2005.

ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street, SW., Nassif Building, 
Room PL-401, Washington, DC.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,

[[Page 12069]]

Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Wayne Lockett, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6447; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Examining the Docket

    You may examine the airworthiness directive (AD) docket on the 
Internet at http://dms.dot.gov or in person at the Docket Management 
Facility office between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The Docket Management Facility office 
(telephone (800) 647-5227) is located on the plaza level of the Nassif 
Building at the street address stated in the ADDRESSES section.

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that supersedes AD 2005-25-03, amendment 
39-14396 (70 FR 72595, December 6, 2005). The existing AD applies to 
certain Boeing Model 737-600, -700, -700C, and -800 series airplanes. 
That NPRM was published in the Federal Register on April 11, 2006 (71 
FR 18251). That NPRM proposed to continue to require replacing the 
point ``D'' splice fitting between windows number 1 and 2 with a new 
splice fitting; performing an eddy current inspection for cracking of 
the holes in the structure common to the new splice fitting, including 
doing any related investigative actions; and performing corrective 
actions if necessary. That NPRM also proposed to add repetitive 
inspections for cracking of the skin just below each splice fitting, 
and related corrective actions if necessary.

Explanation of Revision Service Information

    The NPRM referred to Boeing Alert Service Bulletin 737-53A1222, 
Revision 2, as the appropriate source of service information for the 
inspection of paragraph (g). Boeing has since revised the service 
bulletin. Revision 3, dated January 3, 2007, corrects and clarifies 
certain information and adds fastener options, but adds no additional 
work for airplanes with splice fittings replaced as specified in a 
previous version of the service bulletin. We have revised this final 
rule to refer to Revision 3 of the service bulletin for the inspection 
in paragraph (g), and to provide credit for work done in accordance 
with Revision 2.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments that have been 
received on the NPRM.

Support for the NPRM

    One commenter, Continental Airlines, agrees with the NPRM.

Request To Provide an Alternate Method of Compliance (AMOC)

    KLM Engineering and Maintenance requests that the FAA review the 
inspection methods for the proposed one-time inspection of certain 
fastener locations during the point ``D'' splice fitting replacement. 
The commenter advises that, for certain fastener locations, an eddy 
current open fastener hole is impractical and may not even be possible 
due to structure build-up. The commenter requests that an AMOC be given 
specifying fluorescent penetrant inspections instead of the eddy 
current open fastener hole inspections. The commenter notes that use of 
the fluorescent penetrant inspections has been coordinated with the 
manufacturer.
    Since we issued the NPRM, the manufacturer issued Revision 3 of 
Boeing Alert Service Bulletin (ASB) 737-53A1222. Revision 3, dated 
January 3, 2007, contains procedures for performing fluorescent 
penetrant inspections. This final rule incorporates the revised service 
bulletin; therefore, no AMOC will be necessary to do this type of 
inspection. We have not changed this AD regarding this issue.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 563 airplanes of the affected design in the 
worldwide fleet. We estimate that about 243 airplanes are on the U.S. 
Register, and that the average labor rate is $80 per hour. The 
following table provides the estimated costs for U.S. operators to 
comply with this AD.

                                                 Estimated Costs
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                                                                                    Cost per
                   Action                        Work hours         Parts           airplane        Fleet cost
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Replacing splice fittings with new fittings               36          $15,445          $18,325       $4,452,975
 (required by AD 2005-25-03)................
External detailed inspection (new action)...               1                0               80       \1\ 19,440
----------------------------------------------------------------------------------------------------------------
\1\ Per inspection cycle.

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 have determined that 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:

[[Page 12070]]

    (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); and
    (3) 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket. See the ADDRESSES 
section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-14396 (70 FR 72595, December 6, 2005) and by 
adding the following new airworthiness directive (AD):

2007-06-09 Boeing: Amendment 39-14990. Docket No. FAA-2006-24369; 
Directorate Identifier 2006-NM-001-AD.

Effective Date

    (a) This AD becomes effective April 19, 2007.

Affected ADs

    (b) This AD supersedes AD 2005-25-03.

Applicability

    (c) This AD applies to Boeing Model 737-600, -700, -700C, and -
800 series airplanes, certificated in any category; as identified in 
Boeing Alert Service Bulletin (ASB) 737-53A1222, Revision 3, dated 
January 3, 2007.

Unsafe Condition

    (d) This AD results from full-scale fuselage fatigue testing on 
a splice fitting that failed prior to the design objective on Boeing 
Model 737-800 series airplanes, and a report of a cracked splice 
fitting on an operational airplane. We are issuing this AD to 
prevent cracking of the existing fitting, which may result in 
cracking through the skin and consequent decompression of the flight 
deck.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Restatement of Certain Requirements of AD 2005-25-03

Replacing the Splice Fittings

    (f) Replace the splice fittings with new splice fittings in 
accordance with the Accomplishment Instructions of Boeing ASB 737-
53A1222, Revision 2, dated October 20, 2005, or Revision 3, dated 
January 3, 2007, at the times specified in paragraph (f)(1) or 
(f)(2) of this AD, as applicable. Before further flight, do any 
related investigative actions by accomplishing all the applicable 
actions specified in the Accomplishment Instructions.
    (1) For airplanes that have accumulated fewer than 13,500 total 
flight cycles as December 21, 2005 (the effective date of AD 2005-
25-03): Replace prior to the accumulation of 13,500 total flight 
cycles, or within 1,000 flight cycles after December 21, 2005, 
whichever occurs later.
    (2) For airplanes that have accumulated 13,500 or more total 
flight cycles as of December 21, 2005: Replace at the later of the 
times specified in paragraphs (f)(2)(i) and (f)(2)(ii) of this AD.
    (i) Prior to the accumulation of 18,000 total flight cycles, or 
within 1,000 flight cycles after December 21, 2005, whichever occurs 
first.
    (ii) Within 90 days after December 21, 2005.

New Requirements of This AD

Repetitive Inspections

    (g) Within 24,000 flight cycles after accomplishing the actions 
specified in paragraph (f) of this AD, perform an external detailed 
inspection of the skin just below each splice fitting, in accordance 
with the Accomplishment Instructions of Boeing ASB 737-53A1222, 
Revision 3, dated January 3, 2007. Thereafter, repeat the external 
detailed inspections at intervals not to exceed 24,000 flight 
cycles.

Corrective Actions

    (h) If any cracking is found during any inspection required by 
this AD, prior to further flight, repair in accordance with a method 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), FAA, or with a method approved in accordance with the 
procedures specified in paragraph (j) of this AD.

Acceptable Method of Compliance

    (i) Replacing the splice fitting and any related investigative 
actions before December 21, 2005 (the effective date of AD 2005-25-
03), in accordance with Boeing Service Bulletin 737-53-1222, dated 
June 6, 2002; or Boeing ASB 737-53A1222, Revision 1, dated January 
30, 2003, is acceptable for compliance with the requirements of 
paragraph (f) of this AD. An inspection done before the effective 
date of this AD in accordance with Boeing ASB 737-53A1222, Revision 
2, dated October 20, 2005, is acceptable for compliance with the 
requirements of paragraph (g) of this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle ACO, FAA, has the authority to 
approve AMOCs for this AD, if requested in accordance with the 
procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
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 an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who 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.
    (4) AMOCs approved previously in accordance with AD 2005-25-03, 
amendment 39-14396, are approved as AMOCs for the corresponding 
provisions of paragraphs (f) and (h) of this AD.

Material Incorporated by Reference

    (k) You must use Boeing Alert Service Bulletin 737-53A1222, 
Revision 2, dated October 20, 2005; or Boeing Alert Service Bulletin 
737-53A1222, Revision 3, dated January 3, 2007; to perform the 
actions that are required by this AD, unless the AD specifies 
otherwise.
    (1) The incorporation by reference of Boeing Alert Service 
Bulletin 737-53A1222, Revision 3, dated January 3, 2007, is approved 
by the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51.
    (2) On December 21, 2005 (70 FR 72595, December 6, 2005), the 
Director of the Federal Register approved the incorporation by 
reference of Boeing Alert Service Bulletin 737-53A1222, Revision 2, 
dated October 20, 2005.
    (3) Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for a copy of this service information. You 
may review copies at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue, S.W., Renton, Washington; or 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 March 7, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-4540 Filed 3-14-07; 8:45 am]
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