AD 87-01-01

87-01-01 BOEING: Amendment 39-5493. Applies to the Model 757 series airplanes specified in Boeing Alert Service Bulletin 757-24A0032, dated May 16, 1986, certificated in any category. To minimize the fire hazard associated with overheating of the transformer rectifier unit of the auxiliary power unit starter motor, accomplish the following within 7 months after the effective date of this AD, unless previously accomplished:

A. Replace the 50-ampere circuit breaker used for the auxiliary power unit starter transformer rectifier unit with a 35-ampere circuit breaker in accordance with Boeing Service Bulletin 757-24A0032, dated May 16, 1986, or later FAA-approved revision.

B. 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.

C. Special flight permits may be issued in accordance with FAR 21.197and 21.199 to operate airplanes to a base for the accomplishment of the modification required by this AD.

All persons affected by this directive who have not already received copies of the appropriate service document from the manufacturer may obtain copies upon request to the Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124-2207. This document 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 20, 1987.