AD 93-14-11

93-14-11 BOEING: Amendment 39-8635. Docket 92-NM-201-AD.

Applicability: Model 767 series airplanes, line position 001 through 307, inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the engine bleed air crossover ducts, which could result in loss of pneumatics and damage to adjacent structure, accomplish the following:

(a) OPTION 1: As an alternative to the requirements of paragraph (b) of this AD, accomplish the following:

(1) Within 6 months after the effective date of this AD, or prior to the accumulation of 7,000 total flight cycles, whichever occurs later, conduct a dye penetrant inspection and proof pressure test of the crossover pneumatic ducts, in accordance with Boeing Alert Service Bulletin 767-36A0041, dated July 2, 1992; or Revision 1, dated February 25, 1993.

(i) If cracks or ruptures are detected, prior to further flight, repair or replace the crossover pneumatic ducts in accordance with the service bulletin.

(ii) Stress relieving of the ducts, in accordance with the service bulletin, may be accomplished in conjunction with the initial dye penetrant inspection and proof pressure test required by this paragraph. Such action constitutes terminating action for the requirements of paragraph (a)(2) of this AD.

(2) Within 3,000 flight cycles after accomplishing the initial dye penetrant inspection and proof pressure test required by paragraph (a)(1) of this AD, conduct an additional dye penetrant inspection and proof pressure test of the crossover pneumatic ducts, and stress relieve the crossover pneumatic duct assemblies, in accordance with Boeing Alert Service Bulletin 767-36A0041, dated July 2, 1992; or Revision 1, dated February 25, 1993. If cracks or ruptures are detected, prior to further flight, repair or replace the crossover pneumatic ducts in accordance with the service bulletin.

(b) OPTION 2: As an alternativeto the requirements of paragraph (a) of this AD, accomplish the following:

(1) Within 18 months after the effective date of this AD, or prior to the accumulation of 7,000 total flight cycles, whichever occurs later, conduct a dye penetrant inspection and proof pressure test of the crossover pneumatic ducts and stress relieve the crossover pneumatic duct assemblies, in accordance with Boeing Alert Service Bulletin 767-36A0041, dated July 2, 1992; or Revision 1, dated February 25, 1993.

(2) If cracks or ruptures are detected, prior to further flight, repair or replace the crossover pneumatic ducts in accordance with the service bulletin.

(c) Replacement of all crossover pneumatic ducts with stress relieved ducts in accordance with Boeing Alert Service Bulletin 767-36A0041, dated July 2, 1992; or Revision 1, dated February 25, 1993, constitutes terminating action for the requirements of paragraphs (a) and (b) of this AD.

(d) 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. 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: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

(e) 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.

(f) The inspection, test, repair, and replacement shall be done in accordance with Boeing Alert Service Bulletin 767-36A0041, dated July 2, 1992; or Boeing Service Bulletin 767-36A0041, Revision 1, dated February 25, 1993. 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, 800 North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on September 16, 1993.