AD 93-01-19

93-01-19 BOEING: Amendment 39-8473. Docket 92-NM-130-AD. Supersedes AD 89-08-07, Amendment 39-6186.

Applicability: Model 767 series airplanes with entry or service doors equipped with slide rafts; line positions 002 through 409, inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To ensure opening of entry/service doors when required for emergency evacuation, accomplish the following:

(a) For airplanes having line positions 132, 136, and 140 through 409, inclusive: Within 350 flight hours after May 9, 1989 (the effective date of AD 89-08-07, Amendment 39- 6186), perform an operational check on each entry/service door to detect a broken counterbalance inner torsion spring, in accordance with Boeing Alert Service Bulletin 767-52A0053, dated August 25, 1988; or Revision 1, dated December 22, 1988.

(1) Repeat this operational check thereafter at intervals not to exceed 350 flight hours, until the requirements of paragraph (b) of this AD are accomplished.

(2) If any broken counterbalance inner torsion spring is detected during an operational check, prior to further flight, replace it with an airworthy part in accordance with the service bulletin. After replacement of any counterbalance inner torsion spring, continue to perform the operational checks at intervals not to exceed 350 flight hours until the requirements of paragraph (b) of this AD are accomplished.

(b) For airplanes having line positions 002 through 409, inclusive: Within 425 flight hours after the effective date of this AD, or within 425 flight hours after the last operational check accomplished in accordance with paragraph (a) of this AD, whichever occurs first, determine if the entry/service doors are equipped with a counterbalance assembly using a titanium inner torsion spring, a counterbalance assembly rated for escape slides, an improved counterbalance assembly, or an improved graphite-composite innertorsion spring; and if further action is necessary; in accordance with Section III, paragraphs A. through F., of Boeing Service Bulletin 767-52A0053, Revision 2, dated April 30, 1992. The airplane records may be reviewed in order to make this determination.

NOTE: The part numbers of the "improved" parts referred to in this AD are specified in Section III, paragraphs A. through F., of Boeing Service Bulletin 767-52A0053, Revision 2, dated April 30, 1992.

(1) For those doors equipped with a counterbalance assembly using titanium inner torsion springs, a counterbalance assembly rated for escape slides, an improved counterbalance assembly, or an improved graphite-composite inner torsion spring, no further action is required.

(2) For those doors not equipped with a counterbalance assembly using a titanium inner torsion spring, a counterbalance assembly rated for escape slides, an improved counterbalance assembly, or an improved graphite-composite inner torsion spring: Prior to further flight, perform an operational check to detect the existence of a broken inner torsion spring, in accordance with Section III, paragraph G., of the Boeing service bulletin.

(i) If any broken inner torsion spring is found, prior to further flight, accomplish the procedures specified in either paragraph (b)(2)(i)(A) or (b)(2)(i)(B) of this AD:

(A) Replace the spring with an airworthy part in accordance with Section III., paragraph G., of the Boeing service bulletin, and repeat the operational check at intervals not to exceed 425 flight hours; or

(B) Install an improved counterbalance assembly or an improved graphite-composite inner torsion spring, in accordance with Section III, paragraph H., of the Boeing service bulletin. Such installation constitutes terminating action for the requirements of this AD.

(ii) If no broken inner torsion spring is found, accomplish the procedures specified in either paragraph (b)(2)(ii)(A) or (b)(2)(ii)(B) of this AD:

(A) Repeat the operational check at intervals not to exceed 425 flight hours; or

(B) Install an improved counterbalance assembly or an improved graphite-composite inner torsion spring, in accordance with Section III, paragraph H., of the Boeing service bulletin. Such installation constitutes terminating action for the requirements of this AD.

(c) Installation of a counterbalance assembly using a titanium inner torsion spring, a counterbalance assembly rated for escape slides, an improved counterbalance assembly, or an improved graphite-composite inner torsion spring, in accordance with Section III, paragraph H., of Boeing Service Bulletin 767-52A0053, Revision 2, dated April 30, 1992, constitutes terminating action for the requirements of this AD.

(d) 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.

(e) 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.

(f) The operational checks and replacement procedures shall be done in accordance with Boeing Service Bulletin 767-52A0053, Revision 2, dated April 30, 1992. 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 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.

(g) This amendment becomes effective on March 10, 1993.