AD 2006-07-12 Airworthiness Directives; Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes

Models named: 737-100, -200, -200C, -300, -400, -500 series. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to all Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category.

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 (f) Do a detailed inspection for scribe lines and cracks in the fuselage skin at certain lap joints, butt joints, external repair doublers, and other areas, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1262, dated December 9, 2004, except as provided by paragraphs (g), (j), (k), (l), (m), and (n) of this AD. Do the actions at the time specified in paragraph 1.E., “Compliance,” of the service bulletin, except as required by paragraph (i) of this AD. Acceptable inspection exemptions are described in paragraph 1.E.1. of Boeing Alert Service Bulletin 737-53A1262. (1) If no scribe line is found, no further work is required by this AD. (2) If any scribe line is found: Do all applicable investigative and corrective actions at the time specified by doing all applicable actions specified in the Accomplishment Instructions of the service bulletin, except as required by paragraph (h) of this AD. Note 1: A detailed inspection is defined in Note 10 of Boeing Alert Service Bulletin 737-53A1262 under 3.A., “General Information.” Specific magnification requirements may be specified in the steps of the Work Instructions. Exceptions to and Clarification of Service Bulletin 737-53A1262 Procedures (g) This AD requires accomplishment of Parts 1 through 11 of Boeing Alert Service Bulletin 737-53A1262, dated December 9, 2004. Parts 12 and 13 of the service bulletin may be accomplished, if applicable, to allow temporary return to service. This AD does not require accomplishment of Part 14 of the service bulletin, although the FAA-approved procedures described in Part 14 are acceptable for continued operation with scribe lines found before the applicable compliance time. (h) If any scribe line or crack is found during any inspection required by this AD, and Boeing Alert Service Bulletin 737-53A1262, dated December 9, 2004, specifies to contact Boeing for appropriate action: Before further flight, inspect or repair scribe lines and repair cracks using a method approved in accordance with the procedures specified in paragraph (p) of this AD. (i) Where Boeing Alert Service Bulletin 737-53A1262, dated December 9, 2004, specifies a compliance time after the issuance of the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD. (j) Certain figures are incorrectly identified in Boeing Alert Service Bulletin 737-53A1262, dated December 9, 2004. The figure cited in Part 8, step 3, should be Figure 39, not Figure 38. The figure cited in Part 9, step 4, should be Figure 38, not Figure 39. (k) If the operator's records show that the airplane has never been stripped and repainted under the dorsal fin fairing since delivery from Boeing, then this AD does not require inspections of the butt joint, lap joint, and repair, as specified in paragraph (f) of this AD, in the areas under the dorsal fin fairing. (l) Figure 37 of Boeing Alert Service Bulletin 737-53A1262, dated December 9, 2004, defines “Restricted Zones” at door cutouts as the only affected structure. This AD considers this area to also include Zone 1B. (m) In Figure 1, sheets 2 and 3, of Boeing Service Bulletin 737-53A1262, dated December 9, 2004, the first condition for the initial compliance threshold for Areas B, C, and E is for areas where the cutout modification shown in Boeing Service Bulletin 737-53A1177 was accomplished. This AD considers this condition to also include Zone 1B. (n) In Figure 1, sheets 2 and 3, of Boeing Alert Service Bulletin 737-53A1262, dated December 9, 2004, the second condition for the initial compliance threshold for Areas B, C, and E is for areas where the cutout modification shown in Boeing Service Bulletin 737-53A1177 was not accomplished. This AD considers this condition to apply only to Zone 1A. Reporting Requirement (o) At the applicable time specified in paragraph (o)(1) or (o)(2) of this AD, submit a report of positive findings of cracks found during the inspection required by paragraph (f) of this AD to the Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Alternatively, operators may submit reports to their Boeing field service representatives. The report shall contain, as a minimum, the following information: airplane serial number, flight cycles at time of discovery, location(s) and extent of positive crack findings. Under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq. ), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number 2120-0056. (1) If the inspection was done before the effective date of this AD: Send the report within 30 days after the effective date of this AD. (2) If the inspection was done after the effective date of this AD: Send the report within 30 days after the inspection is done. Alternative Methods of Compliance (AMOCs) (p)(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 14 CFR 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 (AR) 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 approval must specifically refer to this AD. (4) A repair plan approved by a Boeing Company AR or Designated Engineering Representative before the effective date of this AD is acceptable for compliance with the requirements of paragraphs (f)(2) and (h) of this AD, provided the approval was documented via FAA Form 8110-3 or 8100-9, and identified scribe line damage in the title of the form. Material Incorporated by Reference (q) You must use Boeing Alert Service Bulletin 737-53A1262, dated December 9, 2004, 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 March 20, 2006. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 06-3066 Filed 3-30-06; 8:45 am] BILLING CODE 4910-13-P

This AD results from reports of fuselage skin cracks adjacent to the skin lap joints on airplanes that had scribe lines. Scribe line damage can also occur at many other locations, including butt joints, external doublers, door scuff plates, the wing-to-body fairing, and areas of the fuselage where decals have been applied or removed. We are issuing this AD to prevent rapid decompression of the airplane due to fatigue cracks resulting from scribe lines on pressurized fuselage structure.