Analysis of the Flydubai Boeing 737-800 accident at Rostov-on-Don shows the aircraft could have been recovered from its fatal dive just 6s before impact.
Analysis of the Flydubai Boeing 737-800 accident at Rostov-on-Don shows the aircraft could have been recovered from its fatal dive just 6s before impact.
The jet entered a dive as a result of nose-down control column and stabiliser trim input during a go-around attempt on 19 March 2016.
Just 19s before the crash, the aircraft had been climbing through 3,350ft with a nose-up pitch of 10°.
But the captain applied excessive nose-down stabiliser trim for about 12s and the aircraft transitioned to a 40° nose-down attitude – with its engines operating at full thrust.
Russia’s Interstate Aviation Committee has detailed a Boeing engineering simulation which aimed to determine the last point at which the aircraft could have been saved.
Investigators believe the first officer was aware of the deteriorating situation, and the cockpit-voice recorder captured him repeatedly warning the captain, before suddenly exclaiming: “Pull it! Pull it!”
The first officer then attempted to pull the control column, says the inquiry, the flight-data recorder registering a “momentary” aft control column input, more than two-thirds off neutral, before it returned to the forward position.
“If, at that point in time, the control column had been repositioned to a full pull and kept at that position, the aircraft could have been recovered from the descent with a sufficient margin of height,” it adds.
This final opportunity to arrest the dive occurred at 03:41:43, about 6s before the 737 struck the ground.
Sustained full aft column input alone – with no change to trim, flaps or thrust – would have been sufficient to allow the jet to recover at 500ft, transition to a climb and return to normal flight.
The engineering simulation only took into account the aircraft’s aerodynamic performance, and not the state of the pilots.
Investigators point out that the captain was experiencing “complete spatial disorientation”.
Although the enhanced ground-proximity warning system sounded, the inquiry says there was a “lack of appropriate actions” to stem the descent – but adds that, even with such action, the aircraft was beyond recovery.
