AD 2007-26-02 Airworthiness Directives; Boeing Model 757-200, -200CB, and -300 Series Airplanes

Models named: 757-200, -200CB, -300 series. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Boeing Model 757-200, -200CB, and -300 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 757-53A0093, dated November 8, 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/Investigative and Corrective Actions (f) Before the accumulation of 20,000 total flight cycles or within 3,000 flight cycles after the effective date of this AD, whichever is later: Do the applicable inspection specified in paragraph (f)(1) or (f)(2) of this AD by doing all the actions including all applicable related investigative (additional detailed inspections if necessary) and corrective actions; except as provided by paragraph (g) of this AD; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 757-53A0093, dated November 8, 2006. All related investigative and corrective actions must be done before further flight. (1) Do a detailed inspection for cracks of the intercostal tee clips and attachment fasteners at the number 3 and number 4 doorstops of the passenger door cutouts. Repeat the inspection thereafter at intervals not to exceed 3,000 flight cycles until accomplishment of the terminating action specified in paragraph (h) of this AD. (2) Do a detailed inspection with a borescope for cracks of the intercostal tee clips. Repeat the inspection thereafter at intervals not to exceed 3,000 flight cycles until accomplishment of the terminating action specified in paragraph (h) of this AD. (g) If any cracked structure is found during any inspection required by this AD, and the Accomplishment Instructions of Boeing Alert Service Bulletin 757-53A0093, dated November 8, 2006, specify to contact Boeing for appropriate action: Before further flight, repair any cracked structure using a method approved in accordance with the procedures specified in paragraph (i)(2) of this AD. Optional Terminating Action (h) Replacing both intercostal tee clips on the left and right sides with new tee clips in accordance with Part 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 757-53A0093, dated November 8, 2006, terminates the repetitive inspections required by this AD. Alternative Methods of Compliance (AMOCs) (i)(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) 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. (3) 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. Material Incorporated by Reference (j) You must use Boeing Alert Service Bulletin 757-53A0093, dated November 8, 2006, 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 December 10, 2007. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E7-24337 Filed 12-14-07; 8:45 am] BILLING CODE 4910-13-P

This AD results from reports of cracked intercostal tee clips at the number 3 and number 4 doorstops of the passenger door cutouts. We are issuing this AD to detect and correct cracking of the tee clips, which could result in additional stress on the adjacent tee clips, surrounding intercostals, edge frame, door structure and doorstops. This additional stress could cause further cracking or breaking of the tee clips, which could result in failure of the door to seal and consequent rapid decompression of the airplane.