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 Motors of the RB211 jet engine. In 1973, the British government sold the Rolls-Royce car business to allow nationalised parent Rolls-Royce (1971) Limited to concentrate on jet engine manufacture. In 1980, Rolls-Royce Motors was acquired by Vickers. In 1998, Vickers plc decided to sell Rolls-Royce Motors. The leading contender seemed to be BMW, who already supplied internal combustion engines and other components for Rolls-Royce and Bentley cars. Their final offer of £340m was outbid by Volkswagen Group, who offered £430m. As part of the deal, Volkswagen Group acquired the historic Crewe factory, plus the rights to the "Spirit of Ecstasy" mascot