Photograph:
Texas Helicopter OH-13H / M-74A Tomcat VH-FZB (c/n 79-031) at Ingham, QLD in 2011 (NQPS)
Country of origin:
United States of America
Description:
Agricultural work helicopter
Power Plant:
One 180 kw (240 hp) Lycoming TVO-435 six-cylinder horizontally-opposed air-cooled engine
Specifications:
- Rotor diameter: 11.32 m (37 ft 1 in)
- Tail rotor diameter: 1.87 m (6 ft 1 in)
- Rotor disc area: 100.6 m² (1,083 sq ft)
- Fuselage length: 13.30 m (43 ft 6 in)
- Height: 2.84 m (9 ft 3 in)
- Max speed: 196 km/h (122 mph)
- Service ceiling: 3,200 m (10,500 ft)
- Range: 411 km (255 miles)
- Useful load: 463 kg (1,020 lb)
History:
The Bell 47G series of helicopters was purchased and operated by the US Army, USAF, US Navy, British Army and many other forces around the world, the prototype of the series flying for the first time on 8 December 1945. At least 2,400 examples were built and many survive in private use around the world. It was ordered for the US Army in 1947, operated under a range of designations and was named the Sioux, being used for a variety of purposes. Examples were operated by the RNZAF and the Australian Army.
Relevant models here were the OH-13E, being a three-seat variant of the H-13D with dual controls; the OH-13G based on the commercial Bell 47G model with a small elevator on the tail boom; the OH-13H and UH-13H based on the 47G-2 fitted with the Lycomng VO-435 engine; and the OH-13K with a larger diameter rotor and a 168 kw (225 hp) Franklin 6VS-335 engine.
In the United States Texas Helicopter Corp converted a number of examples in recent years for operation by agricultural operators. These involved ex-US Army machines, conversions involving mainly the OH-13E and OH-13H. At least 50 examples have been converted. Models include the M-74 Wasp, a conversion of the ex-US Army OH-13E fitted with a 150 kw (200 hp) Lycoming TVO-435-A1E engine; the M-74A Tomcat, a conversion of the OH-13H powered by a 180 kw (240 hp) Lycoming TVO-435 engine; the M-79S Wasp II fitted with a 200 kw (270 hp) Lycoming TVO-435 engine; and the M-79T Jet Wasp II, a conversion of a Bell 47G powered by a 310 kw (420 hp) Soloy-Allison 250-C20S engine.
A couple of examples have been imported to this part of the world for agricultural use, one, described as an M-74 Tomcat, being imported in February 2009 by Blanchard Aviation of Ingham, QLD, this machine, an ex-OH-13H with the US Army, receiving its Certificate of Registration as N10003 in the United States on 26 June 1979 before being imported for operations in Queensland, becoming VH-FZB² (c/n 79-031) on 18 February 2009.