Formed jointly by Mitchell Engineering Group and Servotec Ltd to develop the Grasshopper twin-engined light helicopter designed by Jacob Shapiro. Powered by two Walter Minor engines, this was first flown in 1962. A second example was built, but the type did not enter production.
James Weir became aware of the CR Twin development and in 1965 decided to give this development financial support. This combination of interests was cemented in a take-over of Rotorcraft Ltd by the Cierva Autogiro Co, which was thereupon renamed the Cierva Rotorcraft Co.