[Federal Register Volume 73, Number 43 (Tuesday, March 4, 2008)]
[Rules and Regulations]
[Pages 11538-11539]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-3810]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0224; Directorate Identifier 2007-NM-188-AD; 
Amendment 39-15400; AD 2008-05-06]
RIN 2120-AA64


 Airworthiness Directives; Boeing Model 737-100, -200, -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 737-100, -200, -300, -400, and -500 series airplanes. This 
AD requires repetitive inspections for fatigue cracking in the 
longitudinal floor beam web, upper chord, and lower chord located at 
certain body stations, and repair if necessary. This AD results from 
several reports of cracks in the center wing box longitudinal floor 
beams, upper chord, and lower chord. We are issuing this AD to detect 
and correct fatigue cracking of the upper and lower chords and web of 
the longitudinal floor beams, which could result in rapid loss of cabin 
pressure.

DATES: This AD is effective April 8, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of April 8, 
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 737-100, -200, -300, -400, and -500 series 
airplanes. That NPRM was published in the Federal Register on November 
26, 2007 (72 FR 65911). That NPRM proposed to require repetitive 
inspections for fatigue cracking in the longitudinal floor beam web, 
upper chord, and lower chord located at certain body stations, and 
repair if necessary.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comment received. Boeing, the single 
commenter, 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 2,852 airplanes of the affected design in the worldwide 
fleet. This AD affects 652 airplanes of U.S. registry. The required 
inspection takes approximately 13 work hours per airplane, at an 
average labor rate of $80 per work hour. Based on these figures, the 
estimated cost of the required inspection for U.S. operators is 
$678,080, or $1,040 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,

[[Page 11539]]

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.

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:

2008-05-06 Boeing: Amendment 39-15400. Docket No. FAA-2007-0224; 
Directorate Identifier 2007-NM-188-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective April 8, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-100, -200, -300, -400, 
and -500 series airplanes, certificated in any category; as 
identified in Boeing Service Bulletin 737-57-1296, dated June 13, 
2007.

Unsafe Condition

    (d) This AD results from several reports of cracks in the center 
wing box longitudinal floor beams, upper chord, and lower chord. We 
are issuing this AD to detect and correct fatigue cracking of the 
upper and lower chords and web of the longitudinal floor beams, 
which could result in rapid loss of cabin pressure.

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.

Repetitive Inspections

    (f) Do the various inspections for fatigue cracks in the 
longitudinal floor beam web, upper chord, and lower chord, located 
at the applicable body stations specified in the Accomplishment 
Instructions of Boeing Service Bulletin 737-57-1296, dated June 13, 
2007, by doing all the actions specified in the Accomplishment 
Instructions of the service bulletin, except as provided by 
paragraph (g) of this AD. Do the inspections at the time specified 
in paragraph (f)(1) or (f)(2) of this AD, as applicable.
    (1) For Groups 1 and 2 airplanes as identified in the service 
bulletin: Do the inspections at the applicable initial compliance 
time listed in paragraph 1.E., ``Compliance,'' of the service 
bulletin; except, where the service bulletin specifies a compliance 
time after the date on the service bulletin, this AD requires 
compliance within the specified compliance time after the effective 
date of this AD. Repeat the inspections thereafter at the intervals 
specified in paragraph 1.E., ``Compliance,'' of the service 
bulletin.
    (2) For Group 3 airplanes as identified in the service bulletin: 
Do the inspections at the applicable initial compliance time listed 
in paragraph 1.E., ``Compliance,'' of the service bulletin; except, 
where the service bulletin specifies a compliance time after the 
date on the service bulletin, this AD requires compliance within the 
specified compliance time after the effective date of this AD. 
Repeat the inspections thereafter at the intervals specified in 
paragraph 1.E., ``Compliance,'' of the service bulletin.
    (g) If any crack is found during any inspection required by this 
AD, and Boeing Service Bulletin 737-57-1296, dated June 13, 2007, 
specifies contacting Boeing for repair instructions: Before further 
flight, repair using a method approved in accordance with the 
procedures specified in paragraph (h) of this AD.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Seattle Aircraft Certification Office, 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.

Material Incorporated by Reference

    (i) You must use Boeing Service Bulletin 737-57-1296, 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 20, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-3810 Filed 3-3-08; 8:45 am]
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