Producing metric drawings and analyzing the materials used in the Derwent V went fairly quickly, but finding a substitute for the high-temperature,
creep-resistant
Nimonic 80 nickel-chromium alloy was a more difficult challenge. Eventually an alloy that matched Nimonic 80's high-temperature properties was found in KhN 80T, but it was not creep-resistant. The first Derwent V copy, designated as the RD-500 (
Reaktivnyy Dvigatel — jet engine) after Factory No. 500 where the engine was first produced, was being tested on 31 December 1947, but problems cropped up quickly. Combustion was uneven and this cracked the combustion chambers. This may have had something to do with the modifications made by the Soviets to the fuel, speed, and starter systems. But these problems were resolved by September 1948 when the engine passed its 100-hour State acceptance test. RD-500 was a close copy of the Derwent with a single-stage
centrifugal compressor, nine
combustion chambers, and a single-stage
turbine. It matched the Derwent's thrust of and was only heavier. The main problem with the engine in service was with its turbine blades, 30% of which failed inspection due to recrystallization after casting. The poor creep resistance of the KhN 80T alloy resulted in dangerous elongation of the turbine blades. Up to 40% of the early production RD-500s had to be individually adjusted before delivery and the service life of the engine never approached the 100 hours demonstrated in the acceptance test. The Soviets had enormous problems building the engines to standard, as demonstrated in the 20,000 man-hours required to build a single engine in 1947. This figure dropped to a more reasonable 7,900 man-hours by November 1948 and declined further still to 4,734 man-hours by 1 March 1949, close to the target of 4,000 man-hours. Production by Factory No. 500 totaled 97 in 1948 and 462 in 1949. Factory No. 16 in
Kazan was brought into the program and built 300 engines in 1949. Production was canceled around 1950 in favor of the superior
Klimov VK-1 turbojet based on the
Rolls-Royce Nene. The RD-500 was used in a number of early Soviet jet fighters including the
Lavochkin La-15, the
Yakovlev Yak-25, and the
Yakovlev Yak-30, but only the
Yakovlev Yak-23,
Yakovlev Yak-25 and
Lavochkin La-15 were accepted for service. The RD-500 was copied and developed further in the
People's Republic of China (PRC) at the Shenyang Aircraft Development Office PF-1A. ==Applications==