AD 92-24-05

92-24-05 BOEING: Amendment 39-8410. Docket No. 92-NM-57-AD. Supersedes AD 91-20- 03, Amendment 39-8037.

Applicability: Model 737-300 series airplanes; as listed in Boeing Alert Service Bulletin 737-71A1208, Revision 2, dated March 23, 1989; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent fuel leakage, which can create a potential fire hazard and lead to subsequent engine shutdown, accomplish the following:

(a) For airplanes listed in Boeing Alert Service Bulletin 737-71A1208, dated December 10, 1987: Within the next 30 days after May 27, 1988 (the effective date of AD 88- 11-01, Amendment 39-5918), inspect the variable stator vane (VSV) fuel manifold for chafing and leaks, and check orientation of the fifth/ninth stage pneumatic duct coupling clamps, in accordance with that service bulletin. Prior to further flight, repair or replace chafed components and relocate components, as necessary, in accordance with the service bulletin.

(b) For Groups 1 and 2 airplanes listed in Boeing Alert Service Bulletin 737- 71A1208, Revision 2, dated March 23, 1989, that are not subject to paragraph (a) of this AD: Within the next 60 days after October 7, 1991 (the effective date of AD 91-20-03, Amendment 39-8037), inspect the VSV fuel manifold for chafing and leaks, and check the orientation of the fifth/ninth stage pneumatic duct coupling clamps, in accordance with that service bulletin. Prior to further flight, repair or replace chafed components and relocate components, as necessary, in accordance with the service bulletin.

(c) For Groups 1 and 2 airplanes listed in Boeing Alert Service Bulletin 737- 71A1208, Revision 2, dated March 23, 1989: Within the next 60 days after the effective date of this AD, and thereafter at each engine change, inspect the VSV fuel manifold for chafing and leaks, and check orientation of the fifth/ninth stage pneumatic duct coupling clamps, in accordance with that service bulletin. Prior to further flight, repair or replace chafed components and relocate components, as necessary, in accordance with the service bulletin.

(d) For Group 3 airplanes listed in Boeing Alert Service Bulletin 737-71A1208, Revision 2, dated March 23, 1989: At each engine change after the effective date of this AD, inspect the VSV fuel manifold for chafing and leaks, and check orientation of the fifth/ninth stage pneumatic duct coupling clamps, in accordance with that service bulletin. Prior to further flight, repair or replace chafed components and relocate components, as necessary, in accordance with the service bulletin.

(e) For all airplanes listed in Boeing Alert Service Bulletin 737-71A1208, Revision 2, dated March 23, 1989: Within 60 days after the effective date of this AD, inspect the fuel supply line for interference of the left fan cowl hold open rod with a fuel supply tube and/or lower clamp; in accordance with that service bulletin. Prior to further flight, repair or replace chafed components and relocate components, as necessary, in accordance with the service bulletin.

(f) Installation of index keyed pneumatic ducts, in accordance with Boeing Alert Service Bulletin 737-71A1208, Revision 2, dated March 23, 1989, constitutes terminating action for the repetitive inspections required by paragraphs (c) and (d) of this AD.

(g) 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.

(h) 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.

(i) The inspections and repairs shall be done in accordance with Boeing Alert Service Bulletins 737-71A1208, dated December 10, 1987; and Revision 2, dated March 23, 1989. This incorporation by reference was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51 as of October 7, 1991 (56 FR 47671, September 20, 1991). 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 Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

This amendment 39-8410, AD 92-24-05, supersedes AD 91-20-03, Amendment 39-8037 which superseded AD 88-11-01, Amendment 39-5918.

(j)This amendment becomes effective on December 11, 1992.