Investigators say an as yet unidentified braking force caused the doomed Yak-42 aircraft to crash during its take-off run, killing 44 people near Yaroslavl earlier this month.
The Interstate Aviation Committee has released new data showing that evidence of a braking force has shown up in detailed examinations of the aircraft’s take-off run. Its nature, however, remains unknown.
It was established that the plane advanced for about 400 meters along the runway. When the aircraft started to take off it failed to gain sufficient height, achieving an altitude of only 5-6m (16-20ft) before tilting left, hitting trees and finally crashing to the ground.
The Yak-42's center of gravity was within safety limits; investigators have already disclosed that the aircraft's weight was not excessive, that its flaps were set to their 20° take-off position, and that its stabilizer was set at the 8.7° pitch-up position.
MAK stated that the Yak-42 pilots had checked all the flight controls, including the elevator which deflected cleanly to a pitch-up position of 21°. The last check was carried out one minute and 40 seconds before the take-off. The aircraft, however, failed to lift off.
"Technical investigators are considering all possibilities for the additional braking force during take-off and the reasons why the aircraft failed to lift off in time from the runway," the IAC added.
Experts say they will use virtual and even live simulations of the Yak-42 air crash to help investigators discover the causes of the tragedy.
During the virtual part computers will reconstruct the deadly crash in detail, and in live – a test pilot will take a similar Yak-42 to the skies.
The simulations will take place in the coming weeks.
The Yak-42 crashed near the city of Yaroslavl killing 44 on September 7.