The Ryan YO-51 Dragonfly was an

observation aircraft A surveillance aircraft is an aircraft used for surveillance. They are operated by military forces and other government agencies in roles such as intelligence gathering, battlefield surveillance, airspace surveillance, reconnaissance, observat ...

designed and built by Ryan Aeronautical for the

United States Army Air Corps The United States Army Air Corps (USAAC) was the aerial warfare service component of the United States Army between 1926 and 1941. After World War I, as early aviation became an increasingly important part of modern warfare, a philosophical r ...

(USAAC). A single-engined

parasol wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

, it was designed for optimum

STOL A short takeoff and landing (STOL) aircraft is a conventional fixed-wing aircraft that has short runway requirements for takeoff and landing. Many STOL-designed aircraft also feature various arrangements for use on airstrips with harsh conditio ...

capability, but although three prototypes proved highly successful in testing, the Stinson YO-49 was judged superior and no production contract was placed.

Design

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. The Dragonfly was a high-wing braced

parasol An umbrella or parasol is a folding canopy (building), canopy supported by wooden or metal ribs that is usually mounted on a wooden, metal, or plastic pole. It is designed to protect a person against rain or sunburn, sunlight. The term ''umbr ...

with fixed tailwheel

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Martin ...

, a two-seat open cockpit, and full-span slots and

Fowler flaps A flap is a high-lift device used to reduce the stalling speed of an aircraft wing at a given weight. Flaps are usually mounted on the wing trailing edges of a fixed-wing aircraft. Flaps are used to reduce the take-off distance and the landing ...

for

capability. It was powered by a single Pratt & Whitney R-985-21 Wasp Junior

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ca ...

.Donald 1997, p.794. At gross weight, the YO-51 could, without flaps, take off after a run of 400 feet, while with full flaps the takeoff run would be only 75 feet, or just four feet more than twice its own length. The Dragonfly was capable of maintaining level flight at speeds as low as , and was claimed as being capable of landing in a distance shorter than the length of the aircraft itself.

Operational history

Nicknamed the "flying motorcycle", 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 The Bellanca YO-50 was a United States prototype observation aircraft, built for the United States Army in 1940. Typical for aircraft of its type, it was a high-wing braced monoplane with fixed tailwheel undercarriage and extensive cabin glazing ...

to supply a new observation and liaison aircraft for use by the USAAC. The YO-51 was the heaviest of the three aircraft evaluated. Although the Dragonfly was considered satisfactory during its flight testing, conducted at

Wright Field Wilbur Wright Field was a military installation and an airfield used as a World War I pilot, mechanic, and armorer training facility and, under different designations, conducted United States Army Air Corps and Air Forces flight testing. Lo ...

in Ohio, the Stinson machine won the production contract, and no further YO-51s were built.Merriam 2002, p.26.

Specifications

References

;Notes ;Bibliography * * * * * * *

External links

O-51 Dragonfly
at Dave's Warbirds {{USAAF observation aircraft YO-51 1940s United States military reconnaissance aircraft Single-engined tractor aircraft Parasol-wing aircraft Aircraft first flown in 1940

Design

Operational history

Specifications

See also

References

External links