AD 2006-08-02 Airworthiness Directives; Boeing Model 747-200C and -200F Series Airplanes

Models named: 747-200C, -200F series. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Boeing Model 747-200C and -200F series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Restatement of Requirements of AD 2004-03-11, but With a New Reduced Threshold and Reduced Repetitive Intervals for Certain Floor Beams: Initial Compliance Time at a New Reduced Threshold (f) At the earliest of the times specified in paragraphs (f)(1) through (f)(3) of this AD, do the inspection required by paragraph (g) of this AD. (1) Before the accumulation of 22,000 total flight cycles, or within 1,000 flight cycles after March 15, 2004 (the effective date of AD 2004-03-11), whichever occurs later. (2) For airplanes with 17,000 or more total flight cycles as of the effective date of this AD: Before the accumulation of 18,000 total flight cycles, or within 90 days after the effective date of this AD, whichever occurs later. (3) For airplanes with fewer than 17,000 total flight cycles as of the effective date of this AD: Before the accumulation of 15,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later. Inspections at Reduced Intervals for Certain Floor Beams and Repair (g) Do the applicable inspection to find fatigue cracking in the upper chord of the upper deck floor beams as specified in Part 1 (Open-Hole High Frequency Eddy Current (HFEC) Inspection Method) or Part 2 (Surface HFEC Inspection Method) of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001. Do the inspections per the service bulletin, except as provided by paragraph (j) of this AD. Any combination of the applicable inspection methods specified in Parts 1 and 2 may be used, provided that the corresponding repetitive inspection interval is used. (1) If any crack is found, before further flight, repair per Part 3 (Upper Chord Repair) of the Work Instructions of the service bulletin; except where the service bulletin specifies to contact Boeing for appropriate action, before further flight, repair according to a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or according to data meeting the certification basis of the airplane approved by an a Boeing Company Designated Engineering Representative (DER) or Authorized Representative for the Boeing Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD. Do the applicable inspection of the repaired area per Part 1 of the Work Instructions of the service bulletin at the applicable time per Part 3 of the Work Instructions of the service bulletin, and repeat the applicable inspection at the applicable interval per Figure 1 of the service bulletin. (2) If no crack is found, repeat the applicable inspection per paragraph (g) of this AD at the applicable time specified in paragraphs (g)(2)(i) through (g)(2)(iii) of this AD. As an option to the repetitive inspections, accomplishment of paragraph (h)(1) or (h)(2) of this AD, before further flight, extends the threshold for the initiation of the repetitive inspections required by this paragraph. (i) If the immediately preceding inspection was conducted using an open-hole HFEC inspection method: Conduct the next inspection of that area within 3,000 flight cycles of the last inspection. (ii) If the immediately preceding inspection was conducted using a surface HFEC inspection method at stations 340 through 420 inclusive and station 500: Conduct the next inspection of that area within 750 flight cycles of the last inspection. (iii) If the immediately preceding inspection was conducted using a surface HFEC inspection method at stations 440 and 520: Conduct the next inspection of that area at the earlier of the times specified in paragraphs (g)(2)(iii)(A) and (g)(2)(iii)(B) of this AD, and thereafter at intervals not to exceed 250 flight cycles. (A) Within 750 flight cycles since the last surface HFEC inspection required by paragraph (g) of this AD. (B) Within 250 flight cycles after the effective date of this AD. Optional Repair/Modification (h) For areas on which the inspection required by paragraph (g) of this AD is done per Part 1 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001, or Revision 1, dated March 10, 2005; and on which no cracking is found: Accomplishment of the actions specified in either paragraph (h)(1) or (h)(2) of this AD extends the threshold for the initiation of the repetitive inspections required by paragraph (g)(2) of this AD. For areas on which the inspection required by paragraph (g) of this AD is done per Part 2 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001, or Revision 1, dated March 10, 2005; and on which no cracking is found: Accomplishment of the actions specified in paragraph (h)(1) of this AD extends the threshold for the initiation of the repetitive inspections required by paragraph (g)(2) of this AD. (1) Do the applicable repair per Part 3 of the Work Instructions of the service bulletin, except as provided by paragraph (j) of this AD. At the applicable time specified in Table 1 of Part 3 of the Work Instructions of the service bulletin, do the applicable inspection of the repaired area per Part 1 of the Work Instructions of the service bulletin. Repeat the inspection thereafter within the applicable interval of 3,000 flight cycles per Figure 1 of the service bulletin. (2) Do the modification of the attachment hole of the floor panel per Figure 5 of the service bulletin, except as provided by paragraph (j) of this AD. Within 10,000 flight cycles after accomplishment of the modification, do the inspection of the modified area per Part 1 of the Work Instructions of the service bulletin. Repeat the inspection thereafter within the applicable interval of 3,000 flight cycles per Figure 1 of the service bulletin. New Requirements of This AD Determining the Number of Flight Cycles for Compliance Time (i) For the purposes of calculating the compliance threshold and repetitive intervals for actions required by paragraphs (f), (g), or (h) of this AD: As of the effective date of this AD, all flight cycles, including the number of flight cycles in which cabin differential pressure is at 2.0 pounds per square inch (psi) or less, must be counted when determining the number of flight cycles that have occurred on the airplane. New Revision of Service Bulletin (j) As of the effective date of this AD, use only the service bulletin specified in Table 1 of this AD. Table 1.—Service Information Do— In accordance with— (1) The actions required by paragraph (g) of this AD Parts 1 and 2 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10,2005; as applicable. (2) The applicable inspection of the repaired area required by paragraph (g)(1) of this AD Parts 1 and 6 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable; at the applicable time per Table 1 of Part 3 of the Work Instructions of the service bulletin. (3) The actions required by paragraph (h)(1) of this AD Parts 1, 3, and 6 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable. (4) The actions required by paragraph (h)(2) of this AD Figure 5 and Part 1 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable. No Reporting Requirement (k) Although the service bulletin referenced in this AD specifies to submit certain information to the manufacturer, this AD does not include that requirement. Alternative Methods of Compliance (AMOCs) (l)(1) The Manager, Seattle Aircraft Certification Office (SACO), 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 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) AMOCs approved previously according to AD 2004-03-11 are approved as AMOCs for the corresponding provisions of paragraphs (f) through (h) of this AD. (4) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office. Material Incorporated by Reference (m) You must use Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001; or Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable; 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 Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. (2) On March 15, 2004 (69 FR 5920, February 9, 2004), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001. (3) 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 31, 2006. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 06-3432 Filed 4-11-06; 8:45 am] BILLING CODE 4910-13-P

This AD results from new reports of cracks in the upper deck floor beams occurring at lower flight cycles. We are issuing this AD to find and fix cracking in certain upper deck floor beams, which could extend and sever floor beams at a floor panel attachment hole location and could result in rapid decompression and loss of controllability of the airplane.