The Rolls-Royce RB.41 Nene was a 1940s British centrifugal compressor turbojet engine. The Nene was essentially an enlarged version of the Rolls-Royce Derwent with the minimal changes needed to deliver 5,000 lbf, making it the most powerful engine of its era. The Nene was Rolls-Royce's third jet engine to enter production, designed and built in an astonishingly short five-month period in 1944, first running on 27 October 1944.
Its only widespread use in Great Britain was in the Hawker Sea Hawk and the Supermarine Attacker. In the US it was built under license as the Pratt & Whitney J42, and it powered the Grumman F9F Panther. Ironically, its most widespread use was in the form of the Klimov RD-45, which powered the famous Mikoyan-Gurevich MiG-15.