Aeroflot accident near Kazakovskoye

On 16 December 1976, the Aeroflot accident near Kozakivske occurred, in which the five occupants of the Yakovlev Yak-40 being used for a test flight died.

Sequence of events

After takeoff at 12:57, at 4,000–4,200 m the pilots made preparations for the upcoming test, in which an uncommanded trimming of the horizontal stabiliser shortly after takeoff was to be simulated. In order to slow down from 340 km/h to the required 200–210 km/h, over the next 55 seconds they reduced engine power from 95 to 53 % and finally to idle. On reaching 270 km/h, the pilots trimmed the stabiliser for the climb and at the same time pulled back on the control column. At 240 km/h, instead of the flaps they extended the landing gear, whereupon the speed dropped below the target value. At first the pilots did not notice this, possibly because they misread the values of the left airspeed indicator and believed themselves to be faster than they actually were. At 175 km/h the pilots noticed it and applied full thrust. Since the engines were still at idle and would have needed 10–12 s to accelerate, the speed dropped to 162–164 km/h, whereupon a stall occurred.

Thereupon the Yak-40 turned to the left and entered a spin. At 13:08:05 the crew reported the loss of control. When the air traffic controller asked who was calling, at 13:08:11 he received the answer: "Высота 2100, падаю" ("Altitude 2100 [m], I am falling"). Again the controller asked "Какой борт?" ("Which flight?"), which was followed by "750". Despite efforts to stop the spin with the ailerons and the rudder each deflected to the right and the elevators pulled up, the Yak-40 struck the ground with no forward speed and at a sink rate of 60 m/s as well as a slight left bank (6°).

The fuselage broke into two parts roughly in the area of the wings, and the vertical tail together with the horizontal tail separated before coming down on the ground again a few metres away. No fire broke out.