calculation and announced, "We've got a 600-mph [] Meteor". Drawings for the 0.855 scale Nene, now known as the Derwent V, were started on 1 January 1945 and on 7 June the engine began a 100-hour test at , soon reaching . Weight was . By 1946 thrust had been increased to using Nimonic 90 turbine blades. The development of the Nene was continued with this scaled-down version, the Derwent V having no direct relationship to the earlier Derwent series. On 7 November 1945, the first official air speed record by a jet aircraft was set by a Meteor F.3 of 606 miles per hour (975 km/h) powered by the scaled-down Nene. Service use The Nene doubled the thrust of the earlier generation engines, with early versions providing about 5,000 lbf (22.2 kN), but remained generally similar in most ways. This should have suggested that it would be widely used in various designs, but the Gloster Meteor proved so successful with its Derwents that the Air Ministry felt there was no pressing need to improve upon it. Instead a series of much more capable designs using the Rolls-Royce Avon were studied, and the Nene generally languished. A total of twenty-five Nenes were sold to the Soviet Union as a gesture of goodwill - with reservation to not use for military purposes - with the agreement of Stafford Cripps. Rolls-Royce were given permission in September 1946 to sell 10 Nene engines to the USSR, and in March 1947 to sell a further 15. The price was fixed under a commercial contract. A total of 55 jet engines were sold to the Soviets in 1947. The Soviets reneged on the deal after the Cold War broke out in 1947, and reverse engineered the Nene to develop the Klimov RD-45, and a larger version, the Klimov VK-1, which soon appeared in various Soviet fighters including Mikoyan-Gurevich MiG-15. Pratt & Whitney acquired a licence to produce the Nene as the Pratt & Whitney J42, and it powered the Grumman F9F Panther which first flew in November 1947. The Nene was used to power the first civil jet aircraft, the Nene Viking, a modified Vickers Viking, the single example of which first flew on 6 April 1948 from Wisley Airfield. It was briefly made under licence in Australia for use in the RAAF de Havilland Vampire fighters. It was also built by Orenda in Canada