AD 2008-17-03 Airworthiness Directives; Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes

This AD applies to the airplanes, certificated in any category, identified in Table 1 of this AD. Table 1—Applicability Boeing model— As identified in Boeing Alert Service Bulletin— 737-100, -200, and -200C series airplanes 737-53A1197, dated August 25, 2006. 737-300, -400, and -500 series airplanes 737-53A1188, Revision 2, dated May 9, 2007, or 737-53A1197, dated August 25, 2006.

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: Service Bulletin 737-53A1188 (f) For airplanes identified in Boeing Alert Service Bulletin 737-53A1188, Revision 2, dated May 9, 2007, including airplanes modified by the repair/preventive change specified in the original version, dated April 9, 1998; or Revision 1, dated March 18, 1999; of the service bulletin: Do detailed and high frequency eddy current (HFEC) inspections in the web and doubler around the slotted holes in the frame web at stringers 15L and 16L, in accordance with the Accomplishment Instructions of Revision 2 of the service bulletin. Do the inspections at the applicable time specified in paragraph 1.E. of Revision 2 of the service bulletin, except as provided by paragraph (h) of this AD. Do all applicable corrective actions before further flight in accordance with Revision 2 of the service bulletin, except as provided by paragraph (i) of this AD. Repeat the inspections at intervals not to exceed 4,500 flight cycles until accomplishment of the repair/preventive change in accordance with Revision 2 of the service bulletin, which terminates the repetitive inspection requirements. A repair/preventive change done in accordance with the original version or Revision 1 of the service bulletin does not terminate the repetitive inspections, but the repetitive inspections may be terminated after the existing kit is replaced with a new kit in accordance with paragraph 3.B., Part II, step 3, or Part III, step 3, of Revision 2 of the service bulletin. Repetitive Inspections: Service Bulletin 737-53A1197 (g) For airplanes identified in Boeing Alert Service Bulletin 737-53A1197, dated August 25, 2006: Do an ultrasound inspection of the slot-shaped cutout in the web for the door stop strap at stringer 16L, an HFEC inspection of the web along the upper and lower edges of the doubler around the doorstop strap at stringer 16L, and a detailed inspection of the web around the doubler for the cutout at stringer 16L, in accordance with the Accomplishment Instructions of the service bulletin. Do the inspections at the applicable time specified in paragraph 1.E. of the service bulletin, except as provided by paragraph (h) of this AD. Do all applicable corrective actions before further flight in accordance with the service bulletin, except as provided by paragraph (i) of this AD. Repeat the inspections at intervals not to exceed 4,500 flight cycles, until accomplishment of the repair/preventive change in accordance with the service bulletin, which terminates the repetitive inspections. Exceptions to Service Bulletin Specifications (h) Where Boeing Alert Service Bulletin 737-53A1188, Revision 2, dated May 9, 2007, and Boeing Alert Service Bulletin 737-53A1197, dated August 25, 2006, specify a compliance time after release of the service bulletin, this AD requires compliance within the specified time after the effective date of this AD. For the initial inspection, the grace period for airplanes that have exceeded the specified threshold is extended to 4,500 flight cycles after the effective date of this AD. (i) Where Boeing Alert Service Bulletin 737-53A1188, Revision 2, dated May 9, 2007, and Boeing Alert Service Bulletin 737-53A1197, dated August 25, 2006, specify to contact Boeing for appropriate action, including repair of damage outside the scope of the service bulletin, repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD. Alternative Methods of Compliance (AMOCs) (j)(1) The Manager, Seattle Aircraft Certification Office, FAA, ATTN: Howard Hall, Aerospace Engineer, Airframe Branch, ANM-120S; telephone (425) 917-6430; fax (425) 917-6590; has the authority to approve AMOCs for this AD, if requested using 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 (k) You must use Boeing Alert Service Bulletin 737-53A1188, Revision 2, dated May 9, 2007; or Boeing Alert Service Bulletin 737-53A1197, dated August 25, 2006; as applicable; 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 August 6, 2008. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E8-18812 Filed 8-18-08; 8:45 am] BILLING CODE 4910-13-P

This AD results from reports of cracks found at the cutout in the web of body station frame 303.9 inboard of stringer 16L. We are issuing this AD to detect and correct such cracking, which could prevent the left forward entry door from sealing correctly, and could cause in-flight decompression of the airplane.