04/30/2009. Remarks by Ray Watkins: "Despite the failure of the C.29 autogyro project, Westland was still keen to continue rotary wing aircraft manufacture and sought the help of a designer with experience in the field for their next venture.

Edward Petter was able to obtain the services of the Frenchman Georges Lepère, who had formed Avions Weymann-Lepère with Schneider Trophy pilot Charles Weymann in 1929. Weymann-Lepère had built several Cierva autogyros, one of which was a small two-seat model known as the CL.10. A direct control version of that aircraft, the CL.10B, which was being tested by the Cierva Autogiro Co. at Hanworth, was loaned to Westland to assist in the project.

Construction work on the CL.20 was begun by Edward Petter and Arthur Davenport in August 1934 and taxiing trials of the prototype, registered G-ACYI, commenced in January 1935 in the hands of Harald Penrose. The aircraft was dismantled and shipped to Hanworth for Juan Cierva to continue the trials, with the first flight taking place on Feb 1935.

Further testing revealed a lack of lift and the aircraft could not be flown at heights greater than 300 ft (91.5 m). Plans were made for the production of six airframes while the problem was being solved but work was abandoned in March 1935 due to higher priority work. G-AYCI was eventually scrapped in 1938."