1944, the US Navy asked the industries to enter a design competition fora 105,000 pound patrol boat powered by four radials. At the end of thetwo German Bv.222 flying boats were captured by US forces.acquired one for evaluation at Naval Air Station, the intensive studiesleading to the hull design of their Model 117. In early 1946, Convairreceived a requirement from the US Navy for a large flying-boat usingthe new laminar flow wing and the developing turboprop technology. It was awarded a contract for two prototypes,designated XP5Y-1 Tradewind. After the first aircraft crash in 1953, theNavy decided not to proceed with the patrol boat version but changed into a passenger and cargo aircraft. The Tradewind program was redesignated R3Y. Six flying boats were builtas the R3Y-2 with a lifting nose for landing ship duties. In practice, it was almost impossible forthe pilots to hold the aircraft steady and nose on to the beach whilethe aircraft was loaded or unloaded. The aircraft were converted intotankers for the in-flight refueling role. Subsequently three moreaircrafts were lost through engine failures, all the Tradewind aircraftswere grounded in 1958.