AD 2008-13-25 Airworthiness Directives; Boeing Model 737-300 and -400 Series Airplanes

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

This AD applies to Boeing Model 737-300 and -400 series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 737-57-1289, dated June 13, 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. Testing/Inspecting/Investigative and Corrective Actions (f) Within 6 months after the effective date of this AD: Do a test of the web panel of the main wheel well pressure deck to determine the material type, and do an ultrasonic inspection to determine material thickness, by doing all the applicable actions specified in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-57-1289, dated June 13, 2007. (g) For airplanes on which the web thickness or material is found to be discrepant during the test and inspection required by paragraph (f) of this AD, accomplish the applicable actions specified in paragraphs (g)(1) and (g)(2) of this AD at the time specified, in accordance with Boeing Special Attention Service Bulletin 737-57-1289, dated June 13, 2007. (1) Except as provided by paragraph (h) of this AD: Do all applicable related investigative and corrective actions (including detailed and general visual inspections) before further flight, by doing all the actions specified in the Accomplishment Instructions of the service bulletin. Repeat the inspections thereafter at intervals not to exceed 1,000 flight cycles until the actions required by paragraph (g)(2) of this AD have been done. For any web panel with a material thickness of less than 0.037 inch, replace the web panel before further flight, in accordance with paragraph 3.B.7. of the Accomplishment Instructions of the service bulletin. Doing this replacement ends the repetitive inspections required by this paragraph. (2) Except as required by paragraph (g)(1) of this AD: Within 30 months or 6,000 flight cycles after accomplishing the actions required by paragraph (g)(1) of this AD, whichever is later, replace the web panel in accordance with the Accomplishment Instructions of the service bulletin. Doing this replacement ends the repetitive inspections required by paragraph (g)(1) of this AD. Corrective Actions (h) If any crack or corrosion is found during any inspection required by paragraph (g)(1) of this AD, and Boeing Special Attention Service Bulletin 737-57-1289, dated June 13, 2007, specifies to contact Boeing for repair instructions: Before further flight, repair according to a method approved in accordance with the procedures specified in paragraph (i) of this AD. Alternative Methods of Compliance (AMOCs) (i)(1) The Manager, Seattle Aircraft Certification Office (ACO), 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 Special Attention Service Bulletin 737-57-1289, 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 June 10, 2008. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E8-14475 Filed 7-7-08; 8:45 am] BILLING CODE 4910-13-P

This AD results from several reports indicating that cracks ranging from 0.8 to 8.0 inches long were found on a certain web panel of the main wheel well pressure deck. We are issuing this AD to prevent fatigue cracking in the web panel of the main wheel well pressure deck, which could result in venting and consequent decompression of the airplane.