05/31/2008. Remarks by Johan Visschedijk: "Almost certainly the first aircraft built specifically as an engine test bed. Folland, General Aircraft and Percival submitted proposals to the Air Ministry complying with Specification 43/37, Folland won the contract and 12 aircraft were produced in 1940, s/n P1774 to P1785. A pilot and two observers were accommodated in a large cabin with complete instrumentation for monitoring engine performance in flight.
Nicknamed the "Folland Frightful" the test beds were fitted with a vast range of high-powered engines, including the 24-cylinder Napier Sabre, the 14-cylinder Bristol Hercules (pictured here), the 18-cylinder Bristol Centaurus, the 12-cylinder Rolls-Royce Griffon, and their sub-versions. Five aircraft were lost between April 28, and September 18, 1944, while the last surviving aircraft was struck off charge on March 17, 1945."