
[Federal Register: January 23, 2009 (Volume 74, Number 14)]
[Rules and Regulations]               
[Page 4117-4119]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23ja09-2]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28283; Directorate Identifier 2006-NM-254-AD; 
Amendment 39-15780; AD 2009-01-02]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800 
and -900 Series Airplanes

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

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 737-600, -700, -700C, -800 and -900 series 
airplanes. This AD requires a one-time general visual inspection of 
frames between body station (BS) 360 and BS 907 to determine if certain 
support brackets of the air conditioning (A/C) outlet extrusions are 
installed; medium- and high-frequency eddy current inspections for 
cracking of the frames around the attachment holes of the subject 
brackets; and repair if necessary. This AD also requires installing 
new, improved fittings for all support brackets of the A/C outlet 
extrusions between BS 360 and BS 907. This AD results from numerous 
reports of multiple cracks in the frames around the attachment holes of 
certain support brackets of the A/C outlet extrusions. We are issuing 
this AD to prevent frame cracking, which, if not corrected, could lead 
to a severed frame that, combined with cracking of the skin lap splice 
above stringer 10, could result in rapid decompression of the airplane.

DATES: This AD becomes effective February 27, 2009.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of February 27, 
2009.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1, fax 206-766-5680; e-mail me.boecom@boeing.com; 
Internet https://www.myboeingfleet.com.

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 (telephone 800-647-5527) is the 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, Washington 98057-3356; telephone (425) 
917-6447; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA issued a supplemental notice of proposed rulemaking (NPRM) 
to amend 14 CFR part 39 to include an AD that would apply to certain 
Boeing Model 737-600, -700, -700C, -800 and -900 series airplanes. That 
supplemental NPRM was published in the Federal Register on August 19, 
2008 (73 FR 48307). That supplemental NPRM proposed to require a one-
time general visual inspection of frames between body station (BS) 360 
and BS 907 to determine if certain support brackets of the air 
conditioning (A/C) outlet extrusions are installed; medium- and high-
frequency eddy current inspections for cracking of the frames around 
the attachment holes of the subject brackets; and repair if necessary. 
That supplemental NPRM also proposed to require installing new, 
improved fittings for all support brackets of the A/C outlet extrusions 
between BS 360 and BS 907.

Comments

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

Request To Revise ``Estimated Costs'' Table

    Boeing requests that we revise the ``Estimated Costs'' table in the 
Cost of Compliance paragraph of the supplemental NPRM to match the 
information specified in Boeing Special Attention Service Bulletin 737-
25-1544, Revision 1, dated January 16, 2008. Boeing states that the 
parts cost in the supplemental NPRM reflects a price range between 
$56,095 and $81,339, while the price range specified in the Boeing 
special attention service bulletin is between $19,854 and $28,789. We 
referred to the Boeing special attention service bulletin as the 
appropriate source of service information for doing the actions 
specified in the supplemental NPRM.
    We agree with the commenter's request to revise the parts cost to 
match the information specified in Boeing Special Attention Service 
Bulletin 737-25-1544, Revision 1, dated January 16, 2008. We have 
revised the parts cost to specify ``between $19,854 and $28,789'' and 
we have revised the corresponding ``Cost per Airplane'' and ``Fleet 
Cost'' columns in the ``Estimated Costs'' table of this AD.

Request To Clarify the References to the Boeing Special Attention 
Service Bulletin

    Boeing requests that we clarify the references to Boeing Special 
Attention Service Bulletin 737-25-1544, Revision 1, dated January 16, 
2008, in paragraphs (g), (g)(2), and (h) of the supplemental NPRM. 
Boeing states that the supplemental NPRM reads ``* * * in accordance 
with Part 2 of the service bulletin * * *'' when the reference is meant 
to be ``* * * in accordance with Part 2 of the accomplishment 
instructions of the service bulletin.

[[Page 4118]]

* * *'' Boeing further states the service bulletin is divided into 
three parts with Part 3 being the accomplishment instructions. Boeing 
notes that the accomplishment instructions are further divided into 
four parts, which are referenced in the supplemental NPRM.
    We agree to clarify the references to Boeing Special Attention 
Service Bulletin 737-25-1544, Revision 1, dated January 16, 2008. 
However, we had already included the phrase ``Accomplishment 
Instructions'' in paragraph (f) of the supplemental NPRM as part of the 
definition of ``service bulletin.'' Paragraph (f) of the supplemental 
NPRM states that ``the term `service bulletin,' as used in this AD, 
means the Accomplishment Instructions of Boeing Special Attention 
Service Bulletin 737-25-1544, Revision 1, dated January 16, 2008.''
    To avoid any confusion as to which part of the service bulletin we 
are referring to in the AD, we have removed paragraph (f) of the 
supplemental NPRM from this AD and revised the subsequent paragraph 
identifiers accordingly. We have also included the phrase 
``Accomplishment Instructions'' in the references to the service 
bulletin in paragraphs (f), (f)(2), and (g) of this AD.

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 1,679 airplanes of the affected design in the 
worldwide fleet. This AD affects about 626 airplanes of U.S. registry. 
The following table provides the estimated costs for U.S. operators to 
comply with this AD, at an average labor rate of $80 per work hour. 
Operators should note that special cold working tools and sleeves will 
be needed if any repair is required, which may increase costs.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                         Cost per
            Action                  Work hours           Parts           airplane              Fleet cost
----------------------------------------------------------------------------------------------------------------
General visual inspection.....  1................  No parts          $80.............  $50,080.
                                                    required.
MFEC and HFEC inspections.....  Between 170 and    No parts          Between $13,600   Up to $10,817,280.
                                 216.               required.         and $17,280.
Replace support fittings......  Between 258 and    Between $19,854   Between $40,494   Up to $35,349,594.
                                 346.               and $28,789.      and $56,469.
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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 
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:
    (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 
adding the following new airworthiness directive (AD):

2009-01-02 Boeing: Amendment 39-15780. Docket No. FAA-2007-28283; 
Directorate Identifier 2006-NM-254-AD.

Effective Date

    (a) This AD becomes effective February 27, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-600, -700, -700C, -800 
and -900 series airplanes; certificated in any category; as 
identified in Boeing Special Attention Service Bulletin 737-25-1544, 
Revision 1, dated January 16, 2008.

Unsafe Condition

    (d) This AD results from numerous reports of multiple cracks in 
the frame around the attachment holes of the support bracket of the 
air conditioning (A/C) outlet extrusion. We are issuing this AD to 
prevent frame cracking, which, if not corrected, could lead to a 
severed frame that, combined with cracking of the skin lap splice 
above stringer 10, could result in rapid decompression of the 
airplane.

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.

Inspections

    (f) Before the accumulation of 36,000 total flight cycles, or 
within 72 months after the effective date of this AD, whichever 
occurs later, except as required by paragraph (h) of this AD: Do a 
general visual inspection to

[[Page 4119]]

determine if the support brackets of the A/C outlet extrusions 
between body station (BS) 360 and BS 907 have two-rivet attachment 
fittings in accordance with Part 2 of the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 737-25-
1544, Revision 1, dated January 16, 2008 (``the service bulletin''), 
except at the locations identified in the notes of Step 3.B.1 of 
Part 1 of the Accomplishment Instructions of the service bulletin.
    (1) For any support bracket attached with three or more rivets: 
No further action is required by paragraph (f) of this AD.
    (2) For any subject support bracket having a two-rivet 
attachment fitting: Before the accumulation of 36,000 total flight 
cycles, or within 72 months after the effective date of this AD, 
whichever occurs later, except as required by paragraph (h) of this 
AD, do medium- and high-frequency eddy current inspections for 
cracking of the frame around the attachment holes of the support 
bracket, in accordance with Part 2 of the Accomplishment 
Instructions of the service bulletin. If any cracking is discovered, 
before further flight, repair the cracking in accordance with Part 3 
of the Accomplishment Instructions of the service bulletin.

Modification

    (g) Except as required by paragraph (h) of this AD: Before the 
accumulation of 36,000 total flight cycles, or within 72 months 
after the effective date of this AD, whichever occurs later, replace 
the support fittings of all A/C outlet extrusions between BS 360 and 
BS 907 with new, improved support fittings, in accordance with Part 
4 of the Accomplishment Instructions of Boeing Special Attention 
Service Bulletin 737-25-1544, Revision 1, dated January 16, 2008.

Compliance Time for Certain Airplanes

    (h) For airplanes on which Boeing Business Jet (BBJ) lower cabin 
altitude modification is incorporated in accordance with 
Supplemental Type Certificate ST01697SE: Before the accumulation of 
18,000 total flight cycles, or within 72 months after the effective 
date of this AD, whichever occurs later, do the actions specified in 
paragraphs (f) and (g) of this AD.

Actions Accomplished According to Previous Issue of Service Bulletin

    (i) Actions accomplished before the effective date of this AD 
according to Boeing Special Attention Service Bulletin 737-25-1544, 
dated October 4, 2006, are considered acceptable for compliance with 
the corresponding actions specified in this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, ATTN: Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM-
120S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 
98057-3356; telephone (425) 917-6447; fax (425) 917-6590; has the 
authority to approve AMOCs for this AD, if requested in accordance 
with the procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (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.

Material Incorporated by Reference

    (k) You must use Boeing Special Attention Service Bulletin 737-
25-1544, Revision 1, dated January 16, 2008, to perform the actions 
that are required by this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this document in accordance with 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) Contact Boeing Commercial Airplanes, Attention: Data & 
Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 
98124-2207; telephone 206-544-5000, extension 1, fax 206-766-5680; 
e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com, 
for a copy of this service information.
    (3) You may review copies of the service information that is 
incorporated by reference 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 or 425-227-1152.
    (4) You may also review copies of the service information 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/code_of_federal_
regulations/ibr_locations.html.

    Issued in Renton, Washington, on December 18, 2008.
Stephen P. Boyd,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service.
[FR Doc. E8-31395 Filed 1-22-09; 8:45 am]

BILLING CODE 4910-13-P
