AD 99-12-08 Airworthiness Directives; Boeing Model 737-200C Series Airplanes

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

All Model 737-200C series airplanes, 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)(1) 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 opening or loss of the cargo door during flight, and consequent rapid decompression of the airplane, accomplish the following: Restatement of Requirements of AD 93-13-02 (a) Prior to the accumulation of 29,000 flight cycles or within 250 flight cycles after August 9, 1993 (the effective date AD 93-13- 02, amendment 39-8615), whichever occurs later, accomplish an external detailed visual inspection to detect cracks of the fuselage skin between stringers 19 left and 25 left and at body stations 360 to 540, in accordance with Boeing Alert Service Bulletin 737- 53A1160, dated October 24, 1991; or Boeing Service Bulletin 737- 53A1160, Revision 1, dated April 29, 1993. If any crack is found, prior to further flight, accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD. (1) Perform an internal detailed visual inspection to detect cracks of the frames between stringers 19 left and 25 left and at body stations 360 to 500B, in accordance with either service bulletin. (2) Repair all cracks in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. (b) Within 3,000 flight cycles after completing the requirements of paragraph (a) of this AD, unless accomplished within the last 6,000 flight cycles prior to August 9, 1993, perform an internal detailed visual inspection to detect cracks of the frames between stringers 19 left and 25 left and at body stations 360 to 500B, in accordance with Boeing Alert Service Bulletin 737-53A1160, dated October 24, 1991; or Boeing Service Bulletin 737-53A1160, Revision 1, dated April 29, 1993. Thereafter, repeat the internal detailed visual inspection at intervals not to exceed 9,000 flight cycles. If any crack is found, prior to further flight, accomplish the requirements of paragraph (b)(1) or (b)(2) of this AD, as applicable. (1) If any crack is found that does not exceed the limits specified in the Boeing 737 Structural Repair Manual (SRM), repair the crack in accordance with the Boeing 737 SRM. Repeat the internal detailed visual inspection thereafter at intervals not to exceed 9,000 flight cycles. (2) If any crack is found that exceeds the limits specified in the Boeing 737 SRM, repair the crack in accordance with a method approved by the Manager, Seattle ACO. Repeat the internal detailed visual inspection thereafter at intervals not to exceed 9,000 flight cycles. New Requirements of This AD (c) Prior to the accumulation of 75,000 total flight cycles, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, install doublers on the frames located between stringers 19 left and 25 left and at body stations 360 to 500B, in accordance with Boeing Service Bulletin 737-53A1160, Revision 1, dated April 29, 1993. Accomplishment of this modification constitutes terminating action for the requirements of this AD. Alternative Methods of Compliance (d)(1) 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. (d)(2) Alternative methods of compliance approved previously in accordance with AD 93-13-02, amendment 39-8615, are [[Page 31490]] approved as alternative methods of compliance with this AD. Note 2: 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 paragraphs (a)(2), (b)(1), and (b)(2) of this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 737-53A1160, dated October 24, 1991; or Boeing Service Bulletin 737-53A1160, Revision 1, dated April 29, 1993. The incorporation by reference of these documents was approved previously by the Director of the Federal Register as of August 9, 1993 (58 FR 36863, July 9, 1993). 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. (g) This amendment becomes effective on July 16, 1999. Issued in Renton, Washington, on June 4, 1999. Vi L. Lipski, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 99-14821 Filed 6-10-99; 8:45 am] BILLING CODE 4910-13-P