AD 2008-05-05 Airworthiness Directives; Boeing Model 737-600, 737-700, 737-700C, 737-800, and 737-900 Series Airplanes

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

This AD applies to certain Boeing Model 737-600, 737-700, 737-700C, 737-800, and 737-900 series airplanes, certificated in any category; as identified in Boeing Service Bulletin 737-53A1242, Revision 2, dated April 23, 2007.

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) Within 2,500 flight cycles or 18 months after the effective date of this AD, whichever occurs first, do the detailed inspections specified in paragraphs (f)(1), (f)(2), and (f)(3) of this AD in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-53A1242, Revision 2, dated April 23, 2007. (1) Do a detailed inspection of the vertical fin lugs, skin, and skin edges for discrepancies (i.e., water ingress; corrosion damage; and missing, insufficient, or cracked sealant). (2) Do a detailed inspection of the flight control cables, fittings, and pulleys in section 48 for signs of corrosion. (3) Do a detailed inspection of the horizontal stabilizer jackscrew, ball nut, and gimbal pins for signs of corrosion. Note 1: For the purposes of this AD, a detailed inspection is: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector (i.e., the person performing the inspection). Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.” Corrective Actions (g) If any discrepancy or corrosion is found during any inspection required by paragraph (f) of this AD, before further flight, do the applicable corrective actions in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-53A1242, Revision 2, dated April 23, 2007; except where the service bulletin specifies to contact Boeing, repair using a method approved in accordance with the procedures specified in paragraph (i) of this AD. Credit for Actions Done Using the Previous Service Information (h) Actions accomplished before the effective date of this AD in accordance with Boeing Service Bulletin 737-53A1242, dated October 17, 2002; or Revision 1, dated April 28, 2005; are considered acceptable for compliance with the corresponding actions specified in paragraphs (f) and (g) of 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) 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 (j) You must use Boeing Service Bulletin 737-53A1242, Revision 2, dated April 23, 2007, 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 February 20, 2008. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E8-3821 Filed 3-3-08; 8:45 am] BILLING CODE 4910-13-P

This AD results from reports indicating that moisture was found within the section 48 cavity. We are issuing this AD to ensure that the correct amount of sealant was applied around the vertical fin lugs, skin and the skin edges. Missing sealant could result in icing of the elevator cables, which could cause a system jam and corrosion of structural and flight control parts, resulting in reduced controllability of the airplane.