In October 1933, the US Navy placed an order with Consolidated and Douglas for prototypes of the new aircraft. The prototype built by Consolidated, designated XP3Y-1, became the flying boat built in the largest number of copies. The internal designation assigned to the design by the company was Consolidated 28. The aircraft, like its predecessor, the P2Y, had a high-mounted wing system. However, the new design used a system of internal stiffeners, which made the wing similar to a cantilever structure. The only exception was two small profiled struts on either side of the aircraft, between the fuselage and the center section. As a result, the version 28 was deprived of the sources of additional aerodynamic drag created in previous designs by struts and stiffeners, which were the cause of the decrease in flight parameters. Another aerodynamic innovation that limited drag was the use of stabilizing floats that folded in flight, forming a profiled wingtip. The twin-redan fuselage was very similar to the P2Y, but in version 28 it had a streamlined, cruciform cantilever tail. The prototype was powered by two 836 hp Pratt-Whitney R-1830-54 Twin Wasp engines mounted on the leading edge of the wing. Armament consisted of four 7.62 mm machine guns and a bomb load of up to 907 kg. The first flight took place on 28 March 1935, after which the XP3Y-1 was immediately transferred to the US Navy for operational testing. The tests proved the P3Y-1's significant superiority over the patrol flying boats in use to date. The long range and improved take-off performance from land-based airfields meant that the US Navy was interested in further developing the design so that it could be used as a patrol bomber. Therefore, in October 1935, the prototype returned to the parent plant for further construction work. These included, among other things, the development of new 912 hp R-1830-64 engines. A redesigned vertical tail was also introduced, and the new prototype, designated XPBY-1, flew on 19 May 1936, and the production PBY-1 soon began to be delivered to the US Navy.
