Firestone XR 9

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, 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-290-7 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 150 horsepower (110 kW) 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

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

 United States

United States Army Air Forces

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.

Specifications (XR-9B)

Data from The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985)

General characteristics

Crew: 2

Length: 27 ft 0 in (8.23 m)

Main rotor diameter: 28 ft 0 in (8.53 m)

Height: 8 ft 6½ in (2.60 m)

Gross weight: 1750 lb (794 kg)

Powerplant: 1 × Avco Lycoming O-290-7 flat-four engine, 135 hp (101 kW) each

Performance

Cruise speed: 80 (approx) mph (129 (approx) km/h)

Service ceiling: 10,000 ft (3050 m)