Rolls-Royce Limited increase its own production rates. By the late 1920s, aero engines made up most of Rolls-Royce's business. Henry Royce's last design was the Merlin aero engine, which was first flown in prototype form in 1935, although he had died in 1933. This was developed from the R engine, which had powered a record-breaking Supermarine S.6B seaplane to almost in the 1931 Schneider Trophy. The Merlin was a powerful supercharged V12 engine and was fitted into many World War II aircraft: the British Hawker Hurricane, Supermarine Spitfire, de Havilland Mosquito (twin-engine), Avro Lancaster (four-engine) (a development of the Avro Manchester with
Rolls-Royce Eagle XVI Rolls-Royce Eagle XVI The Rolls-Royce Eagle XVI was a British experimental 16 cylinder aero engine designed and developed by Rolls-Royce Limited in 1925. The engine was test run but did not fly, the project, together with the planned larger variant, the Eagle XX, was cancelled in favour of the Rolls-Royce Kestrel, that was being developed concurrently. The appearance of the Curtiss D-12, and its importation under license to Britain by Fairey prompted the Air Ministry to ask Rolls-Royce to develop a new aero engine for fighter aircraft, the ministry felt that there were too many engine manufacturers and did not