Bek Air flight 2100 Crash After Take Off
On the 27th of December 2019, Bek Air flight 2100, a domestic passenger flight with 93 passengers and 5 crew on board, crashed after departure from Kazakhstan’s Almaty International airport. The aircraft, a 25-year-old Fokker 100, broke into pieces after crashing into a building, leading to 12 fatalities, including the captain, and 65 people with severe injuries, 22 of whom are still in critical condition.
I know everyone is thinking about the loss of Ukraine International Airlines flight PS 752 in Tehran but right now there’s just not enough information for a reasonable discussion, so I’m going to stick with my original subject, which happened a few weeks earlier.
The captain was the pilot flying and the first officer pilot monitoring. Both flight crew were very experienced and used to cold and icing conditions. The weather and freezing conditions were not out of the ordinary for the airfield, which has comprehensive de-icing and anti-icing procedures.
According to Bek Air, the F100 had been parked at Almaty for two days and there had been no rainfall during this period. They stated that all necessary procedures were carried out. The stabilizers were de-iced but the wings were not as they were clean.
The F100 was configured correctly with zero flaps for departure on runway 05 right. All engines and systems were working normally as the aircraft rotated but at 18 feet above the runway the aircraft started oscillating, rolling right and then left as it lost height and the tail struck the runway. The F100 then climbed to six feet above the runway and then sank again; the tail striking the runway a second time. At the end of the runway, the aircraft again became airborne, reaching eleven feet above the ground and the captain commanded gear up. The speed dropped again and the nose dropped. The plane landed on its belly and glided on the snow travelling 50-55 kph (27-30 knots) through a perimeter fence and then crashed into a two-story house.
The total flight was thirty-six seconds.
There is a number of CCTV videos from the airport. I’ve fast forwarded this one to the point where you can see the Fokker 100 on the runway on the far right of the frame.
This one gives a slightly better view of the oscillations. At the start, the aircraft lights are just visible at the top middle of the screen:
This one shows the whole sequence including breaking through the perimeter fence. The aircraft lights initially show at the top right, above and left of the time stamp:
More CCTV video showing the aircraft and the crash are available on this YouTube Channel listed as Joella Horn.
The airline state that the wind data retrieved from the black boxes shows wind speeds of 96 knots and that they believe that the aircraft was in the vortex of wake turbulence.
An Airbus A321 had departed from the same runway just under two minutes before.
However, AV Herald have posted an argument refuting this conclusion:
Editorial notes: while on the ground the wind measurement by the aircraft systems does not work with any reliability whatsoever, the aircraft was on the ground at that time, the bank angle changed while already skidding on the belly which can explain these values. According to METARs the wind was blowing from 100 to 140 degrees magnetic between 1 and 2 meters/seconds (2-4 knots). The previous departure departed 112 seconds prior to the Fokker 100. Assuming the wind came from 100 degrees during that entire time and thus at an angle of 50 degrees to the runway heading and was blowing at 1 meter/second, any wake turbulence vortices by the previous departure would have been blown left off the runway center line by a minimum of 85 meters (runway width 45 meters) and would have been left off the runway therefore, assuming a wind from 140 degrees at 2 meters/second the wake vortices would have been blown left off the runway center line by 224 meters. Using the wind data off the enhanced FDR diagram while the aircraft was airborne, the aircraft measured the wind from 155 degrees at 6 knots during the first liftoff, from 161 degrees between 5 and 7 knots during the second liftoff and from 132 degrees at 6 knots during the last liftoff. These values would result in the wake vortices blown left off the runway center line by more than 300 meters.
One of the survivors has stated that he saw ice on the wings and that passengers slipped and fell when disembarking via the wing.