A single-engined parasol wing monoplane, it was designed for optimum STOL capability, but although three prototypes proved highly successful in testing, the Stinson YO-49 was judged superior and no production contract was placed.

The design of the YO-51 Dragonfly was typical for aircraft of its type, being optimised for the observation and liaison role, with emphasis on the ability to operate out of the smallest possible airfields.

[1] The Dragonfly was a high-wing braced parasol monoplane with fixed tailwheel landing gear, a two-seat open cockpit, and full-span slots and Fowler flaps for STOL capability.

[6] Nicknamed the "flying motorcycle",[7] three YO-51 aircraft were acquired by the United States Army Air Corps to take part in a fly-off evaluation against the Stinson YO-49 and Bellanca YO-50 to supply a new observation and liaison aircraft for use by the USAAC.

[9] Although the Dragonfly was considered satisfactory during its flight testing,[10] conducted at Wright Field in Ohio,[11] the Stinson machine won the production contract, and no further YO-51s were built.