AD 97-03-19 Airworthiness Directives; Boeing Model 747 Series Airplanes

Models named: 747-100, -200, -300 series. Read the applicability below — it usually turns on serial or part numbers too.

Model 747-100, -200, and -300 series airplanes equipped with an off-wing, two-piece escape slide on Door 3; certificated in any category. Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Required as indicated, unless accomplished previously. To prevent failure of the escape slide to deploy, which could delay and possibly jeopardize the successful emergency evacuation of an airplane, accomplish the following: (a) Within 18 months after November 25, 1992 (the effective date of AD92-16-17, amendment 39-8327), perform an inspection of the door opening thrusters of the escape system in accordance with OEA Service Bulletin 2174200-25-013, dated July 29, 1991. Repeat this inspection thereafter at intervals not to exceed 20 months until the replacement required by paragraph (c) of this AD is accomplished. Note 2: Inspections accomplished in accordance with OEA Service Bulletin 2174200-25-013, Revision 1, dated September 14, 1993; Revision 2, dated November 1, 1993; or Revision 3, dated January 13, 1994; are considered acceptable for compliance with the inspections specified in paragraph (a) of this AD. (b) Within 18 months after November 25, 1992, inspect and modify the door latching mechanism of the escape slide compartment in accordance with Boeing Service Bulletin 747-25-2951, dated August 15, 1991. Note 3: Inspections and modifications accomplished in accordance with Boeing Service Bulletin 747-25-2951, Revision 1, dated May 13, 1993; or Revision 2, dated September 30, 1993; are considered acceptable for compliance with the applicable action specified in paragraph (b) of this AD. (c) Within 2 years after the effective date of this AD, replace the door opening thrusters having part number (P/N) 60B50077-14 or - 17 with new thrusters having P/N 60B50077-19 in accordance with Boeing Service Bulletin 747-25-3073, dated September 21, 1995. Accomplishment of this replacement terminates the repetitive inspections required by this AD. (d) As of 2 years after the effective date of this AD, only door opening thrusters having P/N 60B50077-19 shall be installed on any airplane. (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 4: 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 Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. (g) The inspections and modification shall be done in accordance with OEA Service Bulletin 2174200-25-013, dated July 29, 1991; and Boeing Service Bulletin 747-25-2951, dated August 15, 1991. The incorporation by reference of those documents 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 November 25, 1992 (57 FR 47987, October 21, 1992). The replacement shall be done in accordance with Boeing Service Bulletin 747-25-3073, dated September 21, 1995. The incorporation by reference of that document 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 98124-2207; and OEA Aerospace Inc., P.O. Box KK, Hwy. 12, Explosive Technology Road, Fairfield, California 94533-0659. 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 March 19, 1997. Issued in Renton, Washington, on January 31, 1997. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 97-3027 Filed 2-11-97; 8:45 am] BILLING CODE 4910-13-U