AD 88-05-07

88-05-07 BOEING: Amendment 39-5867. Applies to Model 747 series airplanes, as listed in Boeing Service Bulletin 747-49-2051, dated November 5, 1987, certificated in any category. Compliance required as indicated, unless previously accomplished.

To eliminate the potential for a fire due to fuel leaking from the auxiliary power unit (APU) drain system, accomplish the following:

A. Within the next 30 days after the effective date of this AD, and at intervals not to exceed 30 days thereafter, inspect the APU fuel supply line for fuel leaks, in accordance with Boeing Model 747 Maintenance Manual Section 28-25-00, page 601, dated August 25, 1987, or later FAA-approved revision. If leakage is detected, repair in accordance with the Maintenance Manual, before further flight.

B. Modification of the APU fuel line drain system, fuel pump drain, and turbine drain assembly, in accordance with Boeing Service Bulletin 747-49-2051, dated November 5, 1987, or later FAA-approvedrevision, constitutes terminating action for the repetitive inspection requirement of paragraph A., above.

C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety and which has the concurrence of an FAA Principal Maintenance Inspector, 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 in order to comply with the requirements of 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. This information may be examined at FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington.

This amendment becomes effective March 25, 1988.