The Cierva CR Twin (originally designated CR LTH.1 and also known as the Grasshopper III) was a five-seat utility helicopter that first flew in the UK in 1969. It was a joint development between

Cierva Autogiro Company The Cierva Autogiro Company was a British firm established in 1926 to develop the autogyro. The company was set up to further the designs of Juan de la Cierva, a Spanish engineer and pilot, with the financial backing of James George Weir, a Scotti ...

and

Rotorcraft A rotorcraft or rotary-wing aircraft is a heavier-than-air aircraft with rotary wings or rotor blades, which generate lift by rotating around a vertical mast. Several rotor blades mounted on a single mast are referred to as a rotor. The Internati ...

now a subsidiary of Cierva, based on the dynamic systems of the latter company's

Grasshopper Grasshoppers are a group of insects belonging to the suborder Caelifera. They are among what is possibly the most ancient living group of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grasshopp ...

design. A new, highly streamlined pod-and-boom fuselage was married to the Grasshopper's coaxial rotor system, and the new aircraft registered ''G-AWRP'' first flew on 18 August 1969. Two further prototypes followed, ''G-AXFM'' later in 1969 and ''G-AZAU'' in 1971, this latter example fitted with 210 hp

Continental IO-360 The Continental IO-360 is a family of fuel-injected air-cooled, horizontally opposed six-cylinder aircraft engines manufactured by Continental Motors in the United States of America, now part of AVIC International since 2010. The engine is a ...

-D engines in place of the Rolls-Royce Continental O-300 units of the first two machines. Financial backing could not be obtained for further development, and the project was abandoned by 1975. The first prototype is preserved at

The Helicopter Museum The Helicopter Museum in Weston-super-Mare, North Somerset, England, is a museum featuring a collection of more than 80 helicopters and autogyros from around the world, both civilian and military. It is based at the southeastern corner of the fo ...

Weston-super-Mare Weston-super-Mare, also known simply as Weston, is a seaside town in North Somerset, England. It lies by the Bristol Channel south-west of Bristol between Worlebury Hill and Bleadon Hill. It includes the suburbs of Mead Vale, Milton, Oldmixon ...

Variants

* CR Twin - prototypes (3 built) * CR.420 - proposed production variant with 210 hp Continental TSIO-360-A engines (not built) * CR.640 - proposed production variant with 320 hp Continental Tiara T6-320 engines (not built)

Specifications

References

;Notes ;Bibliography * * * {{Cierva aircraft 1960s British civil utility aircraft 1960s British helicopters Cancelled aircraft projects CR Twin Coaxial rotor helicopters Aircraft first flown in 1969 Twin-engined piston helicopters

Variants

Specifications

See also

References