AD 91-21-06

91-21-06 BRITISH AEROSPACE: Amendment 39-8053. Docket No. 91-NM-122-AD. Applicability: Model BAe 146-100A series airplanes, Serial Numbers up to and including E1152; Model BAe 146-200A series airplanes, Serial Numbers up to and including E2156; and Model BAe 146-300A series airplanes, Serial Numbers up to and including E3157; certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To ensure engine fire extinguisher medium is discharged to proper locations in the event of an engine fire, accomplish the following:

(a) Within 30 days after the effective date of this AD, perform a visual inspection to detect chafing of the extinguisher pipe and clamp assemblies between the two fire extinguisher bottles in the engine nose cowls; and ensure that adequate clearance exists between the three pipe assemblies and the adjacent equipment and structure; in accordance with the instructions in British Aerospace Inspection Service Bulletin 26-A29, Revision 2, dated January 14, 1991.

(b) Prior to the installation of any nose cowl or engine/nose cowl combination on an operational airplane, perform a visual inspection to detect chafing of the extinguisher pipe and clamp assemblies between the two fire extinguisher bottles in the engine nose cowls; and ensure that adequate clearance exists between the three pipe assemblies and the adjacent equipment and structure; in accordance with the instructions in British Aerospace Inspection Service Bulletin 26-A29, Revision 2, dated January 14, 1991.

(c) If any damaged extinguisher pipe and clamp assembly is identified as a result of the inspection required by paragraph (a) or (b) of this AD, prior to further flight, repair or replace the damaged assembly in accordance with instructions in British Aerospace Inspection Service Bulletin 26-A29, Revision 2, dated January 14, 1991.

(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, Standardization Branch, ANM-113, 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, Standardization Branch, ANM-113.

(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 inspection and repair or replacement requirements shall be done in accordance with British Aerospace Inspection Service Bulletin 26-A29, Revision 2, dated January 14, 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 British Aerospace, PLC, Librarian for Service Bulletins, P.O. Box 17414, Dulles International Airport, Washington, D.C. 20041-0414. 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.

This amendment (39-8053, AD 91-21-06) becomes effective on November 19, 1991.