Davis wing

The Davis wing was a World War II-era aircraft wing design used by Consolidated Aircraft on models including the B-24 Liberator. Its airfoil produced less drag than most wings of the time, allowing higher speeds and generating lift at small angles of attack. Its use in designs ended almost immediately after World War II. Reuben H. Fleet, president of Consolidated, met freelance engineer David R. Davis in mid-1937.

Davis sought funding for his "Fluid Foil" airfoil, which he had designed by starting with a low-drag teardrop shape and modifying it for lift. In comparison with conventional designs, Davis's design was relatively thick, having a short chord while still being deep enough to allow a high aspect ratio. Davis claimed it would reduce drag and provide lift at low angles of attack, and its thickness could house fuel or even engines. He approached Consolidated to license it for large flying boats, where low-angle lift would help during takeoff and landing on water.

Fleet and chief engineer Isaac M. Laddon were unimpressed and initially declined. Days later, Laddon changed his mind, and Fleet funded a model and wind tunnel test at Caltech to compare the Davis wing with an in-house design. Initial results were disappointing, but Davis and others concluded the tunnel’s instruments were not sensitive enough. After recalibration, tests showed significantly improved readings.

Real world use

The results were so good that engineers were skeptical. Caltech recalibrated and ran the tests twice more, then delivered a report indicating the wing performed as claimed, though it warned the results might be a wind tunnel fluke. Fleet allowed the wing on Consolidated’s new twin-engine flying boat, the Model 31 XP4Y Corregidor, which first flew on 5 May 1939 and vindicated the design. Consolidated was already working on a secret bomber project to improve on the B-17 Flying Fortress and chose the Davis wing for it.

That project became the Model 32, or B-24 Liberator, first flown on 29 December 1939. The same wing was later used on the B-32 Dominator. The wing was thinner than the B-17’s, and many B-24 units suffered heavy losses because heavily loaded wings often failed structurally when hit by gunfire. Its height required a tricycle landing gear, which made ditching and belly landings more difficult.