The DFS 346 (Samolyot 346) was a German rocket-powered swept-wing aircraft which began development during World War II in Germany.
It was designed by Felix Kracht at the Deutsche Forschungsanstalt für Segelflug (DFS), the "German Institute for Sailplane Flight".
Probably for volume and weight reasons the DFS-346 was equipped with landing skids, both in the original German design and in the later Soviet prototypes; this caused trouble several times.
After launch, the pilot would fire the 346's Walter 509B/C twin-chamber "cruiser" engine to accelerate to a proposed speed of Mach 2.6 and altitude of 30,500 meters (100,000 ft).
After the run was complete the engine would be briefly turned on again, to raise the altitude for a long low-speed glide back to a base in Germany or northern France.
On 22 October 1946, the Soviet OKB-2 (Design Bureau 2), under the direction of Hans Rössing and Alexandr Bereznyak, was tasked with continuing its development.
Newly built 346-1 incorporated minor aerodynamic refinements over the 346-P, and was first flown by Ziese on September 30, 1948, with dummy engines installed.
[4] The pilot seat structure and safety-belt proved to be very unreliable, because at the end of a rough braking course Ziese was thrown forward and struck the canopy with his head, losing consciousness.
Accident investigation research team came to the conclusion that the crash was a result of pilot error, who failed to fully release the landing skid.
Continuing concerns about the aircraft's stability at high speeds had led to a VNE limit of Mach 0.9 being placed during test flights.
Separating from the carrier plane at 9,300 meters (30,500 ft) above Lukovici airfield, the pilot fired the engine and accelerated to a speed of 900 km/h (560 mph).
The rocket engine worked as expected, and 346-3, quickly accelerating, started ascending and soon had flown in very close proximity of its carrier aircraft.