Airworthiness Directive · Amendment 39-13936 · Boeing Model 757-200, -200PF, and -200CB Series Airplanes
Boeing Model 757-200, -200PF, and -200CB Series Airplanes
Model 757-200, -200PF, and -200CB series airplanes, line numbers 1 through 979 inclusive; certificated in any category.
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 757-200, -200PF, and -200CB series airplanes, that requires an inspection of certain ballscrews of the trailing edge flap system to find their part numbers, and replacement of the ballscrews with new, serviceable, or modified ballscrews if necessary. This action is necessary to prevent a flap skew due to insufficient secondary load path of the ballscrew of the trailing edge flaps in the event that the primary load path fails, which could result in possible loss of a flap and reduced controllability of the airplane. This action is intended to address the identified unsafe condition.
To prevent a flap skew due to insufficient secondary load path of the ballscrew of the trailing edge flaps in the event that the primary load path fails, which could result in possible loss of a flap and reduced controllability of the airplane, accomplish the following:
(a) Within 48 months after the effective date of this AD, do an inspection of the ballscrews of the trailing edge flap system to find their part numbers (P/N). If the P/N of the ballscrew is S251N401-5 (Thomson Saginaw P/N 7820921) or S251N401-9 (Thomson Saginaw P/N 7821341), within 48 months after the effective date of this AD, replace the ballscrew with a new, serviceable, or modified ballscrew, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 757-27A0139, dated June 16, 2003.
(b) As of the effective date of this AD, no person may install a trailing edge flap ballscrew, P/N S251N401-5 (Thomson Saginaw P/N 7820921) or S251N401-9 (Thomson Saginaw P/N 7821341), on any airplane.
(c) In accordance with 14 CFR 39.19, the Manager, Seattle Aircraft Certification Office, FAA, is authorized to approve alternative methods of compliance for this AD.
(d) Unless otherwise specified in this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 757-27A0139, dated June 16, 2003. 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 Airplanes, 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 National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/ code_of_federal_regulations/ibr_locations.html.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
