AD 2004-23-10 Airworthiness Directives; Boeing Model 737-700 and -800 Series Airplanes

Models named: 737-700, -800 series. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Boeing Model 737-700 and -800 series airplanes, certificated in any category; having variable and serial numbers listed in Table 1 of this AD. Table 1.—Applicable Variable and Serial Numbers. Variable number Serial number Group YA004 27837 1 YA005 27836 2 YA201 28004 4 YC003 27977 3

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Initial Inspection and/or Repair (f) At the applicable times specified in Table 1 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 737-53-1256, dated September 18, 2003, do the applicable actions specified in Table 2 of this AD in accordance with the Accomplishment Instructions of the service bulletin. Table 2.—Initial Inspection and/or Repair For airplanes identified in the service bulletin as— Requirements— (1) Groups 1, 2, and 3 Do an external ultrasonic inspection for pitting and cracks of the lower skin panel at the lap joint. (2) Groups 1 and 2 Trim the inner skin and install two exterior doublers (including related investigative actions). (3) Group 3 Install three exterior doublers. (4) Group 4 Replace the fuselage skin assembly with a new assembly. Repetitive Inspections (g) For Groups 1, 2, and 3 airplanes identified in Boeing Special Attention Service Bulletin 737-53-1256, dated September 18, 2003: At the applicable times specified in Table 2 of paragraph 1.E., “Compliance,” of the service bulletin, do the repetitive supplemental inspections of the lower skins and external doublers for discrepancies in accordance with the Accomplishment Instructions of the service bulletin. Corrective Action (h) If any discrepancy is found during any action required by this AD, before further flight, repair per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved, the approval must specifically reference this AD. Alternative Methods of Compliance (AMOCs) (i)(1) The Manager, Seattle 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) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the approval must specifically refer to this AD. Material Incorporated by Reference (j) You must use Boeing Special Attention Service Bulletin 737-53-1256, dated September 18, 2003, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approves the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. For information on the availability of this material at the National Archives and Records Administration (NARA), call (202) 741-6030, or go to http://www.archives.gov/federal_ register/code_of_federal_regulations/ibr_locations.html. You may view the AD docket at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW, room PL-401, Nassif Building, Washington, DC. Issued in Renton, Washington, on November 1, 2004. Kalene C. Yanamura, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 04-24936 Filed 11-12-04; 8:45 am] BILLING CODE 4910-13-P

This AD was prompted by a report indicating that localized pitting in the lower skin panels was found during production on a limited number of airplanes. We are issuing this AD to detect and correct premature fatigue cracking at certain lap splice locations and consequent rapid decompression of the airplane.