|FIGHTER||Virtual Aircraft Museum / USSR / Russia / Lavochkin|
A replacement prototype for the La-172 was designated La-174D (the suffix signifying dubler, literally "replacement"), and entered flight test in August 1948. This differed in only minor respects from the preceding prototype, and series production was ordered during the same month as the La-15, armament being reduced from three to two 23mm NS-23 cannon, and 6° of wing anhedral being added. The La-15 was powered by the RD-500 turbojet, the Soviet series version of the Derwent, deliveries to the VVS commencing in the late autumn of 1949. Production plans for the La-15 were, in the event, scaled down because of difficulties experienced in manufacturing in sufficient quantity the numerous milled parts employed in the structure, but several hundred were produced, these remaining in VVS service until 1954. A tandem two-seat conversion trainer version was evolved as the La-180, but only two examples of this variant were built.