07/31/2009. Remarks by
Johan Visschedijk: "The OY-51 was designed to an USAAC specification for a two-seat army co-operation and artillery observation aircraft with STOL capabilities, alike the
Fieseler Fi-156 Storch. Ryan started development in 1938 and to achieve the STOL goals the aircraft was fitted full-span slots to the leading edge of the wings and Fowler flaps of very wide chord to the trailing edge.
(
Johan Visschedijk Collection)
Three aircraft were ordered by the USAAC from Ryan at San Diego, California, in 1939, s/n 40-703, 40-704, and 40-705. Powered by a 440 hp Pratt & Whitney R-985-21 Wasp Junior they were flown in 1940. Test results confirmed the calculated performance, however, the USAAC contract for series production went to the competing Stinson O-49. In October 1941 the three YO-51s were relegated to ground instructional airframes."
