LL-1 Rocketplane 17,224 bytes. 476 x 166 pixels.

The LL was a transonic aerodynamic testbed authorised by LII in September 1945. Three were built: the LL-1 with a straight wing; LL-2 with a conventional swept wing; and LL-3 with a forward swept wing. The LL was towed to a 6 km release altitude by a Tu-2 aircraft. After being cast off, it would fire its Kartukov solid rocket engine and accelerate to the edge of the sound barrier, with a camera photographing air flow on the tufted wing. The LL-2 was not finished because contemporary fighter programs were already providing data on swept wing configurations. But in 1946 to 1948 the LL-1 flew 30 times and the LL-3 100 times, with test pilots M Ivanov, Amet-Khan Sultan, Anokhin, and Rybko at the controls.

Craft.Crew Size: 1. Total Length: 9.0 m. Total Mass: 2,039 kg. Total Propellants: 900 kg. Primary Engine Thrust: 1,500 kgf. Main Engine Propellants: Solid.

In 1946 to 1948 the LL-1 flew 30 times and the LL-3 100 times, with test pilots M Ivanov, Amet-Khan Sultan, Anokhin, and Rybko at the controls.

• 301 - Butowski, Piotr, Air Forces Monthly Special, X-Planes, "Black Reds", February 1998, p. 35.