AD 92-10-08

92-10-08 BOEING: Amendment 39-8242. Docket No. 92-NM-77-AD.

Applicability: Boeing Model 757-200 series airplanes equipped with Rolls-Royce RB211-535 series engines; as listed in Boeing Alert Service Bulletin 757-78A0030, dated January 31, 1992; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent in-flight deployment of both thrust reverser sleeves on one engine, which could result in reduced controllability of the airplane, accomplish the following:

(a) Within 90 days after the effective date of this AD, replace the restrictor union with a standard union, on each engine strut, in the return port of the thrust reverser directional control valve; and perform a functional test of the thrust reverser system; in accordance with Boeing Alert Service Bulletin 757-78A0030, dated January 31, 1992.

(b) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. The request shall be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle ACO.

(c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) The replacement and functional test shall be done in accordance with Boeing Alert Service Bulletin 757-78A0030, dated January 31, 1992. 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 FederalRegister, 1100 L Street NW., Room 8401, Washington, DC.

(e) This amendment becomes effective on June 8, 1992.