AD 86-05-01

86-05-01 BOEING: Amendment 39-5246. Applies to all Model 747 series airplanes equipped with Rolls Royce engines, certificated in any category, listed in Boeing Alert Service Bulletin 747-71A2216, dated December 20, 1985.

To detect faulty self-locking nuts that could lead to separation of an engine, accomplish the following, unless already accomplished:

A. Within 30 days after the effective date of this AD, perform a one-time inspection of the forward engine mount nuts for adequate self-locking torque, in accordance with Boeing Alert Service Bulletin 747-71A2216, dated December 20, 1985, or later FAA-approved revisions.

B. Defective nuts must be replaced prior to further flight.

C. Upon the request of an operator, an FAA Principal Maintenance Inspector, subject to prior approval of the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, may adjust the inspection time in this AD to permit compliance at an established inspection periodof that operator, if the request contains substantiating data to justify the change for that operator.

D. Alternate means of compliance which provide an acceptable level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

E. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD.

All persons affected by this proposal who have not already received information on inspection procedures from the manufacturer may obtain copies upon request to the Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.

This amendment becomes effective March 24, 1986.