AD 91-03-13

91-03-13 BOEING: Amendment 39-6882. Docket No. 89-NM-261-AD.

Applicability: Model 747 series airplanes, as listed in Boeing Service Bulletin 747-57-2253, Revision 1, dated July 5, 1990, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To verify proper application of the center wing fuel tank secondary fuel barrier and prevent fuel or fuel vapors from entering the cargo or passenger compartments, accomplish the following:

A. Within the next 30 months after the effective date of this AD, inspect the center wing fuel tank secondary fuel barrier application, in accordance with Boeing Service Bulletin 747-57-2253, Revision 1, dated July 5, 1990. If the barrier has been improperly applied, as specified in the service bulletin, repair prior to further flight, in accordance with the service bulletin.

B. Within 30 days after accomplishing the inspection required by paragraph A. of this AD, submit a report of the complete findings of inspections from which it is determined that the secondary fuel barrier is not properly applied, to: Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, 1601 Lind Avenue SW., Renton, Washington 98055; rapid fax: (206) 227-1181; telex 756366.

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 (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be submitted directly to the Manager, Seattle ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Seattle ACO.

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 Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington.

This amendment (39-6882, AD 91-03-13) becomes effective on March 11, 1991.