Flight Details
The aircraft was conducting a cargo flight from Ust-Kut to Kirensk. On board were three crew members, two company technicians, and two individuals responsible for the 1,200 kg of cargo.
Accident Sequence
The crew failed to properly prepare for the flight, expediting taxi and departure. The airplane took off from runway 30 at a speed of 155 km/h with an angle of attack of 15°. After rotation, during initial climb at a height of 120 metres and a speed of 210 km/h, the pilot raised the flaps. The aircraft then lost height and descended until it struck trees and crashed in flames 1,500 metres past the runway end.
Casualties
The copilot suffered serious injuries, while all six other occupants were killed. Several hours later, the copilot died from his injuries.
Investigation Findings
The official probable cause was determined as the crew precipitating the takeoff procedure and failing to follow the pre-departure checklist. Contributing factors reported include:
- Poor flight preparation
- The cabin was not heated prior to departure
- The left altimeter was erroneously set 10 mm Hg higher than prescribed
- Stabilizers were set at -6° instead of the required -3.6° angle
- The rotation was completed prematurely
- During initial climb, flaps were raised at a speed of 210-220 km/h, 20 km/h below the speed specified in the Flight Manual
- Lack of visibility
- Lack of ground visual references