AD 2006-16-11 Airworthiness Directives; Boeing Model 737-700 and 737-800 Series Airplanes

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

This AD applies to Boeing Model 737-700 and 737-800 series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 737-53-1236, Revision 1, dated November 10, 2005.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Inspection of Backup Intercostals (f) Before the accumulation of 24,000 total flight cycles, or within 4,500 flight cycles after the effective date of this AD, whichever comes later: Perform a high frequency eddy current (HFEC) inspection for cracking of the backup intercostals located above the cutout for the forward airstair door, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-53-1236, Revision 1, dated November 10, 2005; and, before further flight, do related investigative actions and applicable corrective actions if any crack is found, and other specified corrective actions if no crack is found. Related investigative actions, applicable corrective actions, and other specified corrective actions must be done in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-53-1236, Revision 1, dated November 10, 2005; except where the service bulletin specifies to contact Boeing for repair instructions, repair all cracks using a method approved in accordance with the procedures specified in paragraph (h) of this AD. Actions Accomplished Using Original Issue of Service Bulletin (g) Actions accomplished before the effective date of this AD in accordance with Boeing Service Bulletin 737-53-1236, dated July 11, 2002, are considered acceptable for compliance with the corresponding requirements of this AD. Alternative Methods of Compliance (AMOCs) (h)(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) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office. (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 (i) You must use Boeing Special Attention Service Bulletin 737-53-1236, Revision 1, dated November 10, 2005, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov ; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the 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 July 31, 2006. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E6-12825 Filed 8-8-06; 8:45 am] BILLING CODE 4910-13-P

This AD results from a report of fatigue cracks discovered during a full-scale fatigue test conducted by the manufacturer. We are issuing this AD to detect and correct such cracking, which could result in more extensive fatigue cracking and lead to possible loss of cabin pressure.