EXPERIENCE in Integral Aircraft Fuel-Tank Construction 400153
THE experience of Vought-Sikorsky Aircraft in the development of its present type of integral fuel-tank construction is related in this paper.
Tests made on one type of tape in a seal subjected to aviation gasoline at pressures up to 100 lb per sq in. showed that the tape was not plastic enough to fill in small irregularities in the sheet or extrusions forming the joint. The tests did show, however, that rivets with a washer of this tape inserted under the head did not leak. The experience gained in this work led to the successful method whereby a uniform thickness of cement is applied to the tape instead of the tank surface. Tests showed that this cement-coated tape has the desirable feature of expanding a greater amount than any of the materials tested when in contact with the gasoline.
Concluding, the author announces that spotwelding has been used with success; that one spotwelded tank has had three years of trouble-free service; and that this method shows cost savings on some tanks.