
[Federal Register: March 12, 2008 (Volume 73, Number 49)]
[Rules and Regulations]               
[Page 13109-13111]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr12mr08-15]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0228; Directorate Identifier 2007-NM-107-AD; 
Amendment 39-15421; AD 2008-06-09]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 737-200 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 737-200 series airplanes. This AD requires repetitive 
inspections to detect cracking of the support fittings of the Krueger 
flap actuators, and corrective actions if necessary. This AD also 
requires eventual replacement of any existing aluminum support fitting 
on each wing with a steel fitting, and modification of the aft 
attachment of the actuator. Doing these actions terminates the 
repetitive inspection requirements. This AD results from reports of 
cracking due to fatigue and stress corrosion of the support fittings of 
the Krueger flap actuator. We are issuing this AD to prevent cracking 
of the support fittings, which could result in fracturing of the 
actuator attach lugs, separation of the actuator from the support 
fitting, severing of the hydraulic lines, resultant loss of hydraulic 
fluids, and consequent reduced controllability of the airplane.

DATES: This AD is effective April 16, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of April 16, 
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 737-200 series airplanes. That NPRM was published 
in the Federal Register on November 26, 2007 (72 FR 65909). That NPRM 
proposed to require repetitive inspections to detect cracking of the 
support fittings of the Krueger flap actuators, and corrective actions 
if necessary. The NPRM also proposed to require eventual replacement of 
any existing aluminum support fitting on each wing with a steel 
fitting, and modification of the aft attachment of the actuator. Doing 
these actions terminates the repetitive inspection requirements.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the one 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 about 13 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this AD.

[[Page 13110]]



                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                 Number of U.S.-
                Action                   Work hours     Average labor       Parts          Cost per airplane       registered           Fleet cost
                                                        rate per hour                                               airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection...........................               5             $80              $0  $400, per inspection                   3  $1,200, per inspection
                                                                                        cycle.                                    cycle.
Replacement..........................              88              80          29,642  $36,682.................               3  $110,046.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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.

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:

2008-06-09 Boeing: Amendment 39-15421. Docket No. FAA-2007-0228; 
Directorate Identifier 2007-NM-107-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective April 16, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-200 series airplanes, 
line numbers 814 through 826 inclusive, certificated in any 
category.

Unsafe Condition

    (d) This AD results from reports of cracking due to fatigue and 
stress corrosion of the support fittings of the Krueger flap 
actuator. We are issuing this AD to prevent cracking of the support 
fittings, which could result in fracturing of the actuator attach 
lugs, separation of the actuator from the support fitting, severing 
of the hydraulic lines, resultant loss of hydraulic fluids, and 
consequent reduced controllability 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.

Repetitive Inspections

    (f) Within 12 months after the effective date of this AD, do a 
high frequency eddy current (HFEC) inspection to detect cracking of 
the support fittings of the Krueger flap actuator on each wing, in 
accordance with the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 737-57-1129, Revision 3, dated March 19, 
2007.
    (1) If no cracking is detected, repeat the inspection thereafter 
at intervals not to exceed 3,000 flight hours until the terminating 
action required by paragraph (g) of this AD is accomplished.
    (2) If any cracking is detected, before further flight, do the 
replacement and modification specified in paragraph (g) of this AD.

Terminating Action

    (g) Within 60 months after the effective date of this AD: 
Replace any existing Krueger flap actuator aluminum support fitting 
on each wing with a steel fitting, and modify the actuator aft 
attachment, in accordance with the Accomplishment Instructions of 
Boeing Special Attention Service Bulletin 737-57-1129, Revision 3, 
dated March 19, 2007. Doing this replacement and modification 
terminates the repetitive inspection requirements of paragraph (f) 
of this AD.

Parts Replacement

    (h) As of the effective date of this AD, no person may install 
on any airplane any aluminum support fitting (actuator support 
assembly) identified in the ``Existing Part Number'' column of 
paragraph 2.C. of Boeing Special Attention Service Bulletin 737-57-
1129, Revision 3, dated March 19, 2007.

Actions Accomplished in Accordance With Previous Revisions of Service 
Bulletin

    (i) Actions done before the effective date of this AD in 
accordance with the service bulletins listed in Table 1 of this AD, 
are acceptable for compliance with the corresponding requirements of 
this AD.

            Table 1.--Previous Revisions of Service Bulletins
------------------------------------------------------------------------
                                    Revision
     Boeing service bulletin         level               Date
------------------------------------------------------------------------
737-57-1129......................          1  Oct. 30, 1981.
737-57-1129......................          2  May 28, 1998.
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Alternative Methods of Compliance (AMOCs)

    (j)(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

[[Page 13111]]

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-
57-1129, Revision 3, dated March 19, 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 28, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-4674 Filed 3-11-08; 8:45 am]

BILLING CODE 4910-13-P
