Firestone XR-9
The Firestone XR-9, also known by the company designation Model 45, is a 1940s American experimental helicopter built by the Firestone Aircraft Company for the United [States Army Air Forces]. Only two 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 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 Avco Lycoming XO-290-5 engine. The Model 45C 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,and was renamed the Firestone Aircraft Company in 1946.
A revised two-seat design the revised Model 45C 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-290-7 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. 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;Model 45C
;Model 45C
;Model 45D
;Model 50.
;XR-9
;XR-9A
;XR-9B
;XH-9B