AD 2009-01-02 Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800 and -900 Series Airplanes

Models named: 737-600, -700, -700C, -800, -900 series. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Boeing Model 737-600, -700, -700C, -800 and -900 series airplanes; certificated in any category; as identified in Boeing Special Attention Service Bulletin 737-25-1544, Revision 1, dated January 16, 2008.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Inspections (f) Before the accumulation of 36,000 total flight cycles, or within 72 months after the effective date of this AD, whichever occurs later, except as required by paragraph (h) of this AD: Do a general visual inspection to determine if the support brackets of the A/C outlet extrusions between body station (BS) 360 and BS 907 have two-rivet attachment fittings in accordance with Part 2 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-25-1544, Revision 1, dated January 16, 2008 (“the service bulletin”), except at the locations identified in the notes of Step 3.B.1 of Part 1 of the Accomplishment Instructions of the service bulletin. (1) For any support bracket attached with three or more rivets: No further action is required by paragraph (f) of this AD. (2) For any subject support bracket having a two-rivet attachment fitting: Before the accumulation of 36,000 total flight cycles, or within 72 months after the effective date of this AD, whichever occurs later, except as required by paragraph (h) of this AD, do medium- and high-frequency eddy current inspections for cracking of the frame around the attachment holes of the support bracket, in accordance with Part 2 of the Accomplishment Instructions of the service bulletin. If any cracking is discovered, before further flight, repair the cracking in accordance with Part 3 of the Accomplishment Instructions of the service bulletin. Modification (g) Except as required by paragraph (h) of this AD: Before the accumulation of 36,000 total flight cycles, or within 72 months after the effective date of this AD, whichever occurs later, replace the support fittings of all A/C outlet extrusions between BS 360 and BS 907 with new, improved support fittings, in accordance with Part 4 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-25-1544, Revision 1, dated January 16, 2008. Compliance Time for Certain Airplanes (h) For airplanes on which Boeing Business Jet (BBJ) lower cabin altitude modification is incorporated in accordance with Supplemental Type Certificate ST01697SE: Before the accumulation of 18,000 total flight cycles, or within 72 months after the effective date of this AD, whichever occurs later, do the actions specified in paragraphs (f) and (g) of this AD. Actions Accomplished According to Previous Issue of Service Bulletin (i) Actions accomplished before the effective date of this AD according to Boeing Special Attention Service Bulletin 737-25-1544, dated October 4, 2006, are considered acceptable for compliance with the corresponding actions specified in this AD. Alternative Methods of Compliance (AMOCs) (j)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, ATTN: Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6447; fax (425) 917-6590; 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 (k) You must use Boeing Special Attention Service Bulletin 737-25-1544, Revision 1, dated January 16, 2008, to perform the actions that are required by this AD, unless the AD specifies otherwise. (1) 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. (2) Contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1, fax 206-766-5680; e-mail me.boecom@boeing.com ; Internet https://www.myboeingfleet.com , for a copy of this service information. (3) You may review copies of the service information that is incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221 or 425-227-1152. (4) You may also review copies of the service information 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 18, 2008. Stephen P. Boyd, Assistant Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E8-31395 Filed 1-22-09; 8:45 am] BILLING CODE 4910-13-P

This AD results from numerous reports of multiple cracks in the frame around the attachment holes of the support bracket of the air conditioning (A/C) outlet extrusion. We are issuing this AD to prevent frame cracking, which, if not corrected, could lead to a severed frame that, combined with cracking of the skin lap splice above stringer 10, could result in rapid decompression of the airplane.