AD 93-09-01

93-09-01 BOEING: Amendment 39-8568. Docket 92-NM-209-AD.

Applicability: Model 747-400 series airplanes, passenger and combi configurations, line positions 696 through 906, inclusive; Model 757 series airplanes, line numbers 1 through 488, inclusive; and Model 767 series airplanes, line numbers 1 through 421, inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent an improper electrical connection of the fire extinguishing system due to a damaged discharge cartridge or electrical connector on the fire extinguisher bottle, accomplish the following:

(a) Within 120 days after the effective date of this AD, conduct a detailed visual inspection to detect damage to the discharge cartridges and the electrical connectors on each fire extinguisher bottle installed in auxiliary power unit (APU), cargo compartment, and engine fire extinguishing systems, in accordance with Boeing Alert Service Bulletin 747-26A2210, dated October 29, 1992 (for Model 747-400 series airplanes); Boeing Alert Service Bulletin 757-26A0032, dated October 22, 1992, as amended by Notice of Status Change 757-26A0032 NSC 2, dated February 4, 1993 (for Model 757 series airplanes); or Boeing Alert Service Bulletin 767-26A0089, dated October 22, 1992 (for Model 767 series airplanes); as applicable. The operational tests of the discharge cartridges specified in the Accomplishment Instructions of the applicable service bulletin are not required to be performed prior to accomplishing the detailed visual inspection required by this paragraph. Since an operational test of the fire extinguishing system can be successfully completed even if there is a damaged pin or connector, this inspection must be performed by visually examining the discharge cartridge and the electrical connector.

(b) If any damage is detected during the inspection required by paragraph (a) of this AD, prior to further flight, replace the damaged item with a serviceable part and perform an operational test of the bottle discharge cartridge circuit in accordance with Boeing Alert Service Bulletin 747-26A2210, dated October 29, 1992 (for Model 747-400 series airplanes); Boeing Alert Service Bulletin 757-26A0032, dated October 22, 1992, as amended by Notice of Status Change 757-26A0032 NSC 2, dated February 4, 1993 (for Model 757 series airplanes); or Boeing Alert Service Bulletin 767-26A0089, dated October 22, 1992 (for Model 767 series airplanes); as applicable. Any discrepancy detected as a result of the operational test must be corrected prior to further flight.

(c) The cross-wiring end-to-end functional tests required by AD 89-03-51, Amendment 39-6213, do not have to be accomplished following performance of the inspection required by paragraph (a) of this AD, if the inspection is accomplished one discharge cartridge at a time.

(d) As of the effective date of this AD, no person shall install a fire extinguisher bottleon any airplane unless the discharge cartridge and electrical connector have been inspected in accordance with this AD.

(e) 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.

(f) 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.

(g) The inspection and replacement shall be done in accordance with Boeing Alert Service Bulletin 747-26A2210, dated October 29, 1992 (for Model 747-400 series airplanes); Boeing Alert Service Bulletin 757-26A0032, dated October 22, 1992, and Notice of Status Change 757-26A0032 NSC 2, dated February 4, 1993 (for Model 757 series airplanes); or Boeing Alert Service Bulletin 767-26A0089, dated October 22, 1992 (for Model 767 series airplanes); as applicable. 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 Company, 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.

(h) This amendment becomes effective on June 9, 1993.