AD 86-26-03

86-26-03 BOEING: Amendment 39-5500. Applies to Model 757 series airplanes equipped with Pratt and Whitney Aircraft PW2037 engines, as listed in Boeing Alert Service Bulletin 757- 78A0006, dated August 7, 1986, certificated in any category.

To minimize the potential for uncommanded deployment of a thrust reverser in flight, accomplish the following within 30 days after the effective date of this AD, unless previously accomplished:

A. Inspect and, if necessary, install a restrictor check valve on the control port of both thrust reverser isolation valves in accordance with Boeing Alert Service Bulletin 757- 78A0006, dated August 7, 1986, or later FAA-approved revision.

B. Modify the unlock and auto-restow proximity sensors' installation in accordance with Boeing Alert Service Bulletin 757-78A0006, dated August 7, 1986, or later FAA-approved revision.

C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

D. 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 directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to the Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124-2207. These documents 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 January 12, 1987.