AD 91-25-02

91-25-02 BOEING: Amendment 39-8103. Docket 91-NM-07-AD.

Applicability: Model 747 series airplanes; equipped with BFGoodrich single-piece ramp/slide, part numbers (P/N) 7A1418-1 through -16, for Door 3 evacuation system; certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent failure of the Door 3 evacuation system, accomplish the following:

(a) Within 12 months after the effective date of this AD, accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD:

(1) Modify the regulator assembly, P/N 4A3474-1 (a subassembly of reservoir assembly P/N 4A3416-1), to the P/N 4A3474-2 or 4A3474-3 configuration, by installing improved internal components in accordance with paragraph 2., Accomplishment Instructions, of BFGoodrich Service Bulletin No. 4A3416-25-233, dated December 14, 1990; or Revision 1, dated October 1, 1991.

(2) Reidentify the Door 3 ramp/slide in accordance with paragraph 3.B.,Identification, of BFGoodrich Service Bulletin No. 4A3416-25-233, dated December 14, 1990; or Revision 1, dated October 1, 1991.

(b) 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, Los Angeles Aircraft Certification Office (ACO), 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, Los Angeles ACO.

(c) 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 requirements of this AD.

(d) The modification requirements shall be done in accordance with BFGoodrich Service Bulletin No. 4A3416-25-233, dated December 14, 1990; or BFGoodrich Service Bulletin No. 4A3416-25-233, Revision 1, dated October 1, 1991. This incorporation by reference was approved bythe Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from BFGoodrich Company, Aircraft Evaluation Systems, 3414 South 5th Street, Phoenix, Arizona 85040. Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; or at the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.

(e) This amendment (39-8103), AD 91-25-02, becomes effective on January 9, 1992.