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 and the shape of the radiator grille. However, the Rolls-Royce brand name and logo were controlled by aero-engine maker Rolls-Royce plc, and not Rolls-Royce Motors. The aero-engine maker decided to license the Rolls-Royce name and logo to BMW and not to Volkswagen, largely because the aero-engine maker had recently shared joint business ventures with BMW. BMW paid £40m to license the Rolls-Royce name and "RR" logo, a deal that many commentators thought was a bargain for possibly the most valuable property in the deal. Volkswagen Group had the rights to the mascot and grille but lacked rights to the Rolls-Royce