AD 2009-02-06 Airworthiness Directives; Boeing Model 737-300, -400, and -500 Series Airplanes

Models named: 737-300, -400, -500 series. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Boeing Model 737-300, -400, and -500 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 737-53A1279, dated December 18, 2007.

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 Requirements of AD 2009-02-06 With Clarifications of Compliance Requirements Service Bulletin Reference Paragraph (g) The term “service bulletin,” as used in this AD, means Boeing Alert Service Bulletin 737-53A1279, dated December 18, 2007. (1) 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. (2) The “Condition” column of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-53A1279, dated December 18, 2007, refers to total flight cycles “at the date given on this service bulletin.” However, this AD applies to the airplanes with the specified total flight cycles as of April 15, 2009 (the effective date of AD 2009-02-06). (3) Where the service bulletin specifies to contact Boeing for instructions for removing damage and repairing cracking: Before further flight, remove the damage or repair the cracking using a method approved in accordance with the procedures specified in paragraph (j) of this AD. (4) Although the service bulletin referenced in this AD specifies to submit information to the manufacturer, this AD does not include that requirement. Inspections, Related Investigative Actions, and Corrective Actions (h) At the applicable time specified in paragraph 1.E., “Compliance,” of the service bulletin, except as specified by paragraph (g)(1) of this AD: Do a high frequency eddy current (HFEC) surface inspection or an HFEC hole/edge inspection for cracking of the 1.04-inch nominal diameter wire penetration hole in the frame and frame reinforcement, between stringer S-20 and S-21; and do all applicable related investigative and corrective actions by accomplishing all the actions specified in the Accomplishment Instructions of the service bulletin, except as specified by paragraphs (g)(3) and (g)(4) of this AD. Do all applicable related investigative and corrective actions before further flight. Thereafter, repeat the inspections at the applicable intervals specified in paragraph 1.E., “Compliance,” of the service bulletin. Terminating Action (i) Doing the repair in Part 3 or the preventative modification in Part 5 of the Accomplishment Instructions of the service bulletin terminates the repetitive inspection requirements of this AD. 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 using the procedures found in 14 CFR 39.19. Send information to Attn: Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM-120S, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6447; fax (425) 917-6590. Or, e-mail information to 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov. (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 principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD. (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 Alert Service Bulletin 737-53A1279, dated December 18, 2007, to do the actions required by this AD, unless the AD specifies otherwise. (1) The Director of the Federal Register previously approved the incorporation by reference of Boeing Alert Service Bulletin 737-53A1279, dated December 18, 2007, on April 15, 2009 (74 FR 10469, March 11, 2009). (2) 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. (3) You may review copies of the service information 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 that is incorporated by reference 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 August 26, 2009. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E9-21311 Filed 9-4-09; 8:45 am] BILLING CODE 4910-13-P

This AD results from reports of cracking in the frame, or in the frame and frame reinforcement, common to the 1.04-inch nominal diameter wire penetration hole intended for wire routing. We are issuing this AD to detect and correct cracking in the fuselage frames and frame reinforcements, which could reduce the structural capability of the frames to sustain limit loads, and result in cracking in the fuselage skin and subsequent rapid depressurization of the airplane.