AD 92-07-15

92-07-15 BOEING: Amendment 39-8211. Docket No. 91-NM-167-AD.

Applicability: Model 757 series airplanes; variable numbers NA010, NA011 and NA501 through NA531, and line numbers 142 through 371; certificated in any category. Compliance: Required as indicated, unless accomplished previously.

To prevent the separation of the fixed inboard trailing edge upper panel and consequent damage to airplane structure, hydraulic lines, and wire bundles, accomplish the following:

(a) For airplanes having variable numbers NA010, NA011, and NA501 through NA531: Within the next 18 months after the effective date of this AD, accomplish the procedures specified in either subparagraph (a)(1) or (a)(2) of this AD:

(1) Determine the panel assembly part number of the left and right wing in accordance with Boeing Service Bulletin 757-57-0036, dated June 13, 1991 . (i) If a panel assembly part number is 113N1611-9 (left), -10 (right), -11 (left), or -12 (right): No further actionis required.

(ii) If a panel assembly part number is 113N1611-13 (left), -14 (right), -15 (left), or -16 (right): Prior to further flight, modify the fixed inboard trailing edge upper panel in accordance with Boeing Service Bulletin 757-57-0036, dated June 13, 1991.

(2) With the panel installed on the airplane, locate a small area on the sloped surface of the panel near one of the three edges where fasteners are installed through the panel. Sand the small area with light pressure until paint, primer, and Tedlar protective film layers are removed.

(i) If the exposed skin layer is any color other than black, no further action is required.

(ii) If the exposed skin layer is black, modify the fixed inboard trailing edge upper panel, prior to further flight, in accordance with Boeing Service Bulletin 757-57-0036, dated June 13, 1991.

(b) For airplanes having line numbers 142 through 371: Within the next 18 months after the effective date of this AD, modify thefixed inboard trailing edge upper panel in accordance with Boeing Service Bulletin 757-57-0036, dated June 13, 1991.

(c) 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.

(d) 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.

(e) The inspection and modifications shall be done in accordance with Boeing Service Bulletin 757-57-0036, dated June 13, 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. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, DC.

(f) This amendment becomes effective on May 5, 1992.