The Lavochkin bureau’s response to Yosif Stalin’s order of February 1945 to design and build a single-seat jet fighter around a Junkers Jumo 004B turbojet, was the La-150 of pod-and-boom layout with a shoulder-mounted wing.
Like the competitive designs from the Mikoyan-Gurevich and Yakovlev bureaux, the La-150 was awarded a prototype/pre-series aircraft order, the first of the prototypes flying in September 1946 powered by the Soviet derivative of the Junkers Jumo 004B axial-flow turbojet engine, the RD-10 rated at 900kg.

The February 1945 Soviet requirement for a jet-powered fighter specified a single 1984-lb (900-kg) thrust RD-10, and the limited power of this engine dictated that the designers had to exercise considerable ingenuity in keeping down weight and optimizing the engine installation. The Lavochkin team’s response was a small machine and a pod-and-boom fuselage allowing the use of an efficient straight-through design from the circular nose inlet to the nozzle under the boom. Five prototypes were built for trials from late 1946, but the type was beset by problems including a high structure weight and sluggish performance. Excessive dihedral effect resulting from the wing positioning was rectified on the second prototype by drooping the wingtips, but excessive oscillation of the tail surfaces at high speeds resulting from inadequate stiffness of the tailboom could not be overcome.

The Yak 17 Feather was slightly faster and lighter than its competitor, the La 150, and was substantially superior in range; rough field performance of the Yak 17 was very much better than that of the Lavochkin design, which had a heavy narrow track undercarriage. The La 150 was abandoned in April 1947 and the Yak 17 was ordered into production.

Max take-off weight: 2961 kg / 6528 lb
Empty weight: 2059 kg / 4539 lb
Wingspan: 8.20 m / 26 ft 11 in
Length: 9.42 m / 30 ft 11 in
Wing area: 12.15 sq.m / 130.78 sq ft
Max. speed: 805 km/h / 500 mph
Range: 500 km / 311 miles
Armament: 2 x 23mm NS-23 cannon.

The final development of this straight-winged series was the La-174TK, which first flew January 1948 as a research type for the investigation of very thin, straight wings as an alternative to swept wings in overcoming compressibility problems.
The wing possessed a thickness ratio of only 6% (the “TK” suffix indicating Tonkoye Krylo, or Thin Wing) which the Lavochkin bureau believed might offer most of the advantages of a thicker sweptback wing while avoiding some of its disadvantages. The 6 per cent thickness/chord ratio was the smallest in the world at that time, and yielded performance benefits over the La-56. The basic configuration of the La-174TK reverted to that of the earlier La-152 series fighters, although the relationship was confined to a common design origin, with the single 1590kg NII-1 (RD-500) turbojet exhausting under the rear fuselage. Armament comprised three 23mm NS-23 cannon and flight testing commenced early 1948. Although lighter than the La-172, the La-174TK demonstrated inferior handling and performance characteristics, further development being discontinued.
The La-174TK was intended only for research and no production was ever planned.

La-174TK
Engine: 1590kg NII-1 (RD-500) turbojet
Wingspan: 8.64 m / 28 ft 4 in
Length: 9.41 m / 30 ft 10 in
Wing area: 13.52 sq.m / 145.53 sq ft
Max take-off weight: 3315 kg / 7308 lb
Empty weight: 2310 kg / 5093 lb
Max. speed: 970 km/h / 603 mph
Range: 960 km / 597 miles