Lavochkin La-15 / La-174D / La-180
A replacement prototype for the La-172 was designated La-174D (the suffix signifying dubler, literally "replacement"), and entered flight test in August 1948. Lavochkin scaled down the basic La-174TK design to produce the La-174D tailored round the smaller Rolls-Royce Derwent turbojet. 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 degrees 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 about 400 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.
Engine: RD-500 turbojet, 3527-lb (1600-kg) thrust
Max take-off weight: 3850 kg / 8488 lb
Empty weight: 2575 kg / 5677 lb
Wingspan: 8.8 m / 28 ft 10 in
Length: 9.0 m / 29 ft 6 in
Wing area: 16.2 sq.m / 174.38 sq ft
Max. speed: 1025 km/h / 637 mph
Ceiling: 13000 m / 42650 ft
Range: 1170 km / 727 miles