AD 91-22-51

91-22-51 BOEING: Amendment 39-8129. Docket 91-NM-214-AD. Final Rule of Telegraphic AD T91-22-51.

Applicability: Model 757 series airplanes, line numbers 140 through 335, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent the separation of the trailing edge wedges from the airplane, accomplish the following:

(a) Perform a close detailed visual inspection of the trailing edge wedges of slats 1 through 4 and 7 through 10, for delamination and physical damage in accordance with Boeing Alert Service Bulletin 757-57A0045, dated October 16, 1991, at the times specified below:

(1) For airplanes that have accumulated 5,000 or more flight hours as of the effective date of this AD: Within the next 10 calendar days after the effective date of this AD, and thereafter at intervals not to exceed 300 flight hours.

(2) For airplanes that have accumulated less than 5,000 flight hours as of the effective date of this AD: Within the next 300 flight hours after the effective date of this AD, and thereafter at intervals not to exceed 300 flight hours.

(b) Within the next 300 flight hours after the effective date of this AD, perform a "coin-tap" inspection of the trailing edge wedges of slats 1 through 4 and 7 through 10 for delamination and physical damage, in accordance with Boeing Alert Service Bulletin 757- 57A0045, dated October 16, 1991, Repeat this inspection at intervals not to exceed 1,500 flight hours.

(c) If delamination and/or physical damage are found as a result of the inspections required by paragraph (a) or (b) of this AD, prior to further flight, repair in accordance with an FAA-approved procedure or replace with new parts. If a repair is accomplished or if new parts are installed, the inspections required by paragraphs (a) and (b) of this AD must be continued.

(d) 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.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle ACO.

(e) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

(f) The inspections required by this AD shall be done in accordance with Boeing Alert Service Bulletin 757-57A0045, dated October 16, 1991. 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 S.W., Renton, Washington; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.

(g) This amendment (39-8129, AD 91-22-51) becomes effective on January 24, 1992, to all persons except those persons to whom it was made immediately effective by telegraphic AD T91-22-51, issued October 17, 1991, which contained the requirements of this amendment.