AD 79-20-11

79-20-11 BOEING: Amendment 39-3583. Applies to Boeing Model 747 series airplanes certificated in all categories. Compliance required as indicated. To improve the lightning protection design of the fuel system, accomplish the following: Within 5000 hours time in service or fifteen calendar months from the effective date, whichever occurs first, modify the fuel systems as follows, unless already accomplished or an equivalent modification was incorporated during production:

A. Rework the outboard wing fuel system components in accordance with Boeing Service Bulletin 747-28-2068, Revision 3, dated September 28, 1979, or later FAA-approved revisions. B. Install wiring shrouds and a relay circuit for the fuel quantity system in accordance with Boeing Service Bulletin 747-28-2069 dated June 1, 1979, Revision 1 dated October 5, 1979, or later FAA-approved revisions. C. Replace the nonmetallic fuel tank and dry bay access doors in accordance with Boeing Service Bulletin 747-57-2035 dated December 18, 1970, and 747-28-2084 Revision 1, dated June 8, 1979, or later FAA-approved revisions. Equivalent modifications may be used when approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region, 9010 East Marginal Way South, Seattle, Washington 98108. The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer, may obtain copies upon request to Boeing Commercial Airplane Company, Post Office Box 3707, Seattle, Washington 91824. These documents may also be examined at FAA Northwest Region, 9010 East Marginal Way South, Seattle, Washington 98108.

This amendment becomes effective October 15, 1979.