Polikarpov U-1

Osoaviakhima

The airplane departed Moscow on a local training flight with two pilots on board. En route, the crew encountered engine problems and was able to make an emergency landing near Tushino. Mechanics were called to make a check of the engine but nothing particular was noted and the crew was cleared for takeoff. Nevertheless, the captain took off with a mechanic on board to proceed with in-flight tests. Shortly after takeoff, at a height of about 100-150 metres, the airplane entered an uncontrolled descent and crashed, killing both occupants.

Dobrolet

Crashed in unknown circumstances somewhere in Russia in 1929. The exact date of the mishap remains unknown.