The Firestone XR-9, also known by the company designation Model 45, was a 1940s

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

experimental helicopter built by the

Firestone Aircraft Company Firestone Tire and Rubber Company is a tire company founded by Harvey Firestone (1868–1938) in 1900 initially to supply solid rubber side-wire tires for fire apparatus, and later, pneumatic tires for wagons, buggies, and other forms of wheeled ...

for the

United States Army Air Forces The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...

. Only two (the military XR-9B and one civil example) were built.

Development

Originally developed by G & A Aircraft with the co-operation of the United States Army Air Forces' Air Technical Service Command, the G & A Model 45B (designated XR-9 ''Rotocycle'' by the Army) was a design for a single-seat helicopter of pod-and-boom configuration. It had a fixed tri-cycle landing gear and three-bladed main and tail rotors. Power would have been supplied by a 126 hp (94 kW) Avco Lycoming XO-290-5 engine. The Model 45C (XR-9A) was the same helicopter with a two-bladed rotor. Neither of the two helicopters were built. G & A Aircraft was purchased by Firestone in 1943,Merriam 2002, p. 64 and was renamed the Firestone Aircraft Company in 1946. A revised two-seat design the revised Model 45C (or XR-9B) was built with a three-bladed main rotor and two-seat in tandem. The first aircraft procured by the Army Air Forces in 1946, it was powered by an Avco

Lycoming O-290 Lycoming may refer to the following, most of which are at least partly in Lycoming County, Pennsylvania, United States: Geography * Lycoming, New York, a hamlet * Lycoming County, Pennsylvania * Lycoming Township, Lycoming County, Pennsylvania * Ly ...

-7 engine and first flew in March of that year. A civil version, the Model 45D was also built and flown, in anticipation of a postwar boom in aircraft sales. This differed in having the two occupants side-by-side instead of tandem as in the 45C, and was equipped with a Lycoming engine. The prototype was demonstrated at the 1946 Cleveland

National Air Races The National Air Races (also known as Pulitzer Trophy Races) are a series of pylon and cross-country races that have taken place in the United States since 1920. The science of aviation, and the speed and reliability of aircraft and engines grew ...

.'' A four-seat Model 50, with twin tail rotors, was also projected, but the predicted sales boom did not materialise, and Firestone closed its aircraft manufacturing division.

Variants

;Model 45B :Unbuilt single-seat helicopter with three-bladed rotor, Army designation XR-9. ;Model 45C :Unbuilt single-seat helicopter with two-bladed rotor, Army designation XR-9A. ;Model 45C (revised) :Tandem two-seat helicopter powered by an Avco Lycoming O-290-7 engine and two-bladed rotor, one built as the XR-9B, later re-designated the XH-9B. ;Model 45D :Side-by-side two-seat helicopter for civil market, one built. ;Model 50. :Four-seat version, not built. ;XR-9 :Army designation for the unbuilt Model 45B ;XR-9A :Army designation for the unbuilt Model 45C ;XR-9B :Army designation for the Model 45C (revised), later redesignated XH-9B ;XH-9B :XR-9B re-designated in 1948.

Operators

; :

Survivors

The sole Model 45D is in non-display storage at the Army Aviation Museum at Fort Rucker, Alabama. It is painted as an XR-9 46-001. The sole Model 45D has recently been refurbished and is now on display (without blades installed) at the Army Aviation Museum at Fort Rucker, Alabama

Specifications (XR-9B)

References

Notes

Bibliography

* Andrade, John. ''U.S. Military Aircraft Designations and Serials since 1909''. Hinckley, Leicastershire, UK: Midland Counties Publications, 1979. . * ''The

Illustrated Encyclopedia of Aircraft The ''Illustrated Encyclopedia of Aircraft'' was a weekly partwork magazine by Aerospace Publishing (an imprint of Orbis Publishing) which was published in the United Kingdom (and sold in other countries too) during the early 1980s. The magazine ...

'' (Part Work 1982–1985). London: Orbis Publishing, 1985. * Lambermont, Paul Marcel. ''Helicopters and Autogyros of the World''. London: Cassell and Company Ltd, 1958. ASIN B0000CJYOA. * Merriam, Ray
''World War II Journal #15: U.S. Warplanes of World War II, Volume 1''
Bennington, Vermont: Merriam Press, 2002. .

External links

* {{USAF helicopters R-09 1940s United States helicopters 1940s United States military utility aircraft Aircraft first flown in 1946 Single-engined piston helicopters