85-21-51: Elevator Actuator Rod End Bolt Retaining Nuts

85-21-51 Boeing; Applies to Boeing Model 767-200 airplanes, certificated in any category. To prevent loss of certain critical airframe self-locking nuts, accomplish the following, unless previously accomplished:\n\n\tA. Within 35 landings or 10 days after the effective date of this AD, whichever occurs first, inspect the horizontal elevator self-locking nuts in accordance with Boeing Alert Service Bulleting 767-27A0064, dated October 25, 1985, or later FAA-approved revision. Self-locking nuts found to be insecure in accordance with the criteria specified in the service bulletin must be replaced before further flight with serviceable self-locking nuts.\n\n\tB. Within 50 landings or 20 days after the effective date of this AD, whichever occurs first, inspect the inboard aft trailing edge flap self-locking nuts and the outboard wing spoiler actuator self-locking nuts in accordance with Boeing Alert Service Bulletin 767-27A0064, dated October 25, 1985, or later FAA-approved revision.Self-locking nuts found to be insecure in accordance with the criteria specified in the service bulletin must be replaced before further flight with serviceable self-locking nuts.\n\n\tC. 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.\n\n\tAll persons affected by this directive who have not already received the appropriate service document from the manufacturer may obtain copies upon request to Boeing Commercial Airplane Company, P. O. Box 3707, Seattle, Washington 98124. This document may also be examined at FAA Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.\n\n\tThis amendment becomes effective February 24, 1986 as to all persons, except those persons to whom it was made immediately effective by telegraphic AD T85-21-51, issued October 25, 1985.