Airworthiness Directives; Boeing Model 737-300, -400, and -500 Series Airplanes

[Federal Register Volume 73, Number 40 (Thursday, February 28, 2008)]
[Rules and Regulations]
[Pages 10649-10650]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-3461]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0226; Directorate Identifier 2007-NM-187-AD; 
Amendment 39-15393; AD 2008-04-21]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-300, -400, and -500 
Series 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 
Boeing Model 737-300, -400, and -500 series airplanes. This AD requires 
repetitive inspections for cracking of the body buttock line (BBL) 0.07 
floor beam between body station (BS) 651 and BS 676 and between BS 698 
and BS 717, and related investigative and corrective actions if 
necessary. This AD also provides an optional terminating action for the 
repetitive inspections. This AD results from reports of cracking in the 
BBL 0.07 floor beam. We are issuing this AD to prevent failure of the 
main deck floor beams at certain body stations due to fatigue cracking, 
which could result in rapid decompression of the airplane.

DATES: This AD is effective April 3, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of April 3, 
2008.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.

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: Nancy Marsh, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6440; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an airworthiness directive (AD) that would apply to 
certain Boeing Model 737-300, -400, and -500 series airplanes. That 
NPRM was published in the Federal Register on November 26, 2007 (72 FR 
65901). That NPRM proposed to require repetitive inspections for 
cracking of the body buttock line 0.07 floor beam between body station 
(BS) 651 and BS 676 and between BS 698 and BS 717, and related 
investigative and corrective actions if necessary.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comment received. Boeing supports the NPRM.

Conclusion

    We reviewed the relevant data, considered the comment received, and 
determined that air safety and the public interest require adopting the 
AD as proposed.

Costs of Compliance

    There are 1,961 airplanes of the affected design in the worldwide 
fleet. This AD affects 599 airplanes of U.S. registry. The required 
inspections take about 4 work hours per airplane, at an average labor 
rate of $80 per work hour. Based on these figures, the estimated cost 
of the required AD for U.S. operators is $191,680, or $320 per 
airplane, 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

    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.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

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

[[Page 10650]]

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 FAA amends Sec.  39.13 by adding the following new AD:

2008-04-21 Boeing: Amendment 39-15393. Docket No. FAA-2007-0226; 
Directorate Identifier 2007-NM-187-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective April 3, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-300, -400, and -500 
series airplanes, certificated in any category; as identified in 
Boeing Service Bulletin 737-57-1210, Revision 2, dated June 13, 
2007.

Unsafe Condition

    (d) This AD results from reports of cracking in the body buttock 
line (BBL) 0.07 floor beam. We are issuing this AD to prevent 
failure of the main deck floor beams at certain body stations due to 
fatigue cracking, which 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 and Related Investigative/Corrective Actions

    (f) Before the accumulation of 20,000 total flight hours, or 
within 7,000 flight cycles after the effective date of this AD, 
whichever occurs later: Do the detailed inspections for cracking of 
the BBL 0.07 floor beam between body station (BS) 651 and BS 676 and 
between BS 698 and BS 717, and do all the applicable related 
investigative and corrective actions before further flight, by 
accomplishing all of the applicable actions specified in paragraphs 
B.2. and B.4. of the Accomplishment Instructions of Boeing Service 
Bulletin 737-57-1210, excluding Appendix A, Revision 2, dated June 
13, 2007, except as provided by paragraph (g) of this AD. Repeat the 
inspections thereafter at intervals not to exceed 7,000 flight 
cycles. Installing a repair in accordance with paragraphs B.2. and 
B.4. of the Accomplishment Instructions of the service bulletin, or 
doing the modification in accordance with paragraph (h) of this AD, 
terminates the repetitive inspections for the applicable area only.

Exception to Corrective Action

    (g) If any cracking is found during any inspection required by 
this AD, and Boeing Service Bulletin 737-57-1210, excluding Appendix 
A, Revision 2, dated June 13, 2007, specifies to contact Boeing for 
appropriate action: Before further flight, repair the cracking using 
a method approved in accordance with the procedures specified in 
paragraph (i) of this AD.

Optional Terminating Action

    (h) If no cracking is found during the detailed inspection and 
related investigative action required by paragraph (f) of this AD: 
Accomplishing the modification of the BBL 0.07 floor beam between BS 
651 and BS 676 and between BS 698 and BS 717, as applicable, in 
accordance with paragraphs B.2. and B.4., as applicable, of the 
Accomplishment Instructions of Boeing Service Bulletin 737-57-1210, 
excluding Appendix A, Revision 2, dated June 13, 2007, terminates 
the repetitive inspections for the applicable area only.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Seattle Aircraft Certification Office (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) 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

    (j) You must use Boeing Service Bulletin 737-57-1210, Revision 
2, dated June 13, 2007, to do the actions required by this AD, 
unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 
98124-2207.
    (3) You may review copies of the service information 
incorporated by reference at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., 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/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on February 15, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-3461 Filed 2-27-08; 8:45 am]
BILLING CODE 4910-13-P

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