Anigrand Craftswork - 1/72 Budd C-93/RB-1 Conestoga. In 1941, the U.S. War Department required for a twin-engine transport comparable in performance to the Douglas C-47, to be constructed of non-strategic materials. At the time, U.S. government feared that the thousands of new aircraft needed for the war effort might create shortages of aluminum alloys. Sprang from this requirement, the Curtiss C-76 and Fairchild C-82 were to be constructed of wood. A third respondent, Budd, proposed to design an aircraft made of stainless steel. The U.S. Navy accepted the proposal and placed an order for 200, to be designated RB-1. The U.S. Army Air Forces followed with an order for 600, designated C-93. The RB-1/C-93 prototype first flew in October 1943. The aircraft demonstrated greater than expected fuel consumption and was relatively underpowered. By late 1943, other more conventional cargo aircraft were being produced in large numbers. This caused the Army to cancel its order for the C-93 and the Navy to reduce its RB-1 order from 200 to 25, of which 17 were delivered in March 1944.