AD 2001-13-23 Airworthiness Directives; Boeing Model 737-700 and -800 Series Airplanes

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

Model 737-700 and -800 series airplanes; line numbers 4, 6, 9 through 20 inclusive, 29, and 31 through 46 inclusive; certificated in any category. Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Required as indicated, unless accomplished previously. To prevent fatigue cracking along the bulkhead-to-fuselage attachment, which could result in structural failure of the aft pressure bulkhead and consequent rapid decompression of the airplane, accomplish the following: Inspections and Corrective Actions (a) Prior to the accumulation of 3,000 total flight cycles, or within 90 days after the effective date of this AD, whichever occurs later, do one-time special detailed inspections of tension bolts at the attachment of the aft pressure bulkhead to the fuselage at body station 1016 to determine whether the correct parts are installed, per the Accomplishment Instructions of Boeing Service Bulletin 737-53-1212, including Appendix A, dated August 13, 1998. (1) If any long bolt is found above the main deck floor, do paragraphs (a)(1)(i) and (a)(1)(ii) of this AD. (i) Before further flight, do a torque test of the nut on the long bolt to determine whether the bolt is properly clamped. (ii) Replace the bolt and nut, as applicable, with new parts, per the service bulletin, except as provided by paragraph (c) of this AD. The correct replacement parts are listed in Figure 4 of the service bulletin. Do the replacement no later than the compliance time specified in the compliance table in Section 1.D. (“Compliance”) of the service bulletin. For the purposes of this AD, compliance times stated in flight cycles and years are to be counted from the time of the inspection per paragraph (a) of this AD. (2) For any long or short bolt other than those identified in paragraph (a)(1) of this AD, replace the bolt and nut, as applicable, with new parts, per the service bulletin, except as provided by paragraph (c) of this AD. The correct replacement parts are listed in Figure 4 of the service bulletin. Do the replacement no later than the compliance time specified in the compliance table in Section 1.D. (“Compliance”) of the service bulletin. For the purposes of this AD, compliance times stated in flight cycles and years are to be counted from the time of the inspection per paragraph (a) of this AD. Note 2: For the purposes of this AD, a special detailed inspection is defined as: “An intensive examination of a specific item(s), installation, or assembly to detect damage, failure, or irregularity. The examination is likely to make extensive use of specialized inspection techniques and/or equipment. Intricate cleaning and substantial access or disassembly procedures may be required.” Repetitive Inspections (b) Where short bolts are installed between two adjacent stringer end fittings or at stringer end fittings, doing repetitive inspections of the nuts to determine if bolts are properly clamped, per Boeing Service Bulletin 737-53-1212, including Appendix A, dated August 13, 1998, extends the compliance time for the replacement of bolts, per the compliance table in Section 1.D. (“Compliance”) of the service bulletin. Exception for Certain Repair Conditions (c) Where Boeing Service Bulletin 737-53-1212, including Appendix A, dated August 13, 1998, specifies to contact Boeing for replacement instructions: Before further flight, replace per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative 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 approval letter must specifically reference this AD. Alternative Methods of Compliance (d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. Special Flight Permits (e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. Incorporation by Reference (f) Except as provided by paragraph (c) of this AD, the actions shall be done in accordance with Boeing Service Bulletin 737-53-1212, including Appendix A, dated August 13, 1998. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. Effective Date (g) This amendment becomes effective on August 13, 2001. Issued in Renton, Washington, on June 27, 2001. Vi L. Lipski, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 01-16740 Filed 7-5-01; 8:45 am] BILLING CODE 4910-13-U