AD 99-20-10 Airworthiness Directives; Boeing Model 727 Series Airplanes

Models named: 727 series. Read the applicability below — it usually turns on serial or part numbers too.

Model 727 series airplanes; line numbers 124, 126, 130, 146, 221, 287, 331, 339, 345, 355, 416, 439, 516, 532, 540, 608, 631, 650, 717, 777, 788, 791, 837, and 1087; 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 (b) 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 cracking of the pressure web of the nose landing gear wheel well, which could result in loss of airplane pressurization, accomplish the following: Modification (a) Prior to the accumulation of 60,000 total flight cycles, or within 4 years after the effective date of this AD, whichever occurs later, install reinforcement straps and stiffeners on the sidewall, top, and forward bulkhead panels of the pressure web of the [[Page 53621]] nose landing gear wheel well, in accordance with Part II of the Accomplishment Instructions of Boeing Service Bulletin 727-53-0145, Revision 1, dated December 7, 1989. Alternative Methods of Compliance (b) 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 Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate; or in accordance with 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. 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 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 (c) Special flight permits may be issued in accordance with Secs. 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 (d) The modification shall be done in accordance with Boeing Service Bulletin 727-53-0145, Revision 1, dated December 7, 1989. 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. (e) This amendment becomes effective on November 8, 1999. Issued in Renton, Washington, on September 22, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 99-25219 Filed 10-1-99; 8:45 am] BILLING CODE 4910-13-P