I think an engine failed at ~1,300 ft
Look at the graph on page 6 of this thread.
The flight lasted 3 min, 45 sec
00:00 Takeoff roll commenced
01:00 Rotate
01:45 Lower the nose, accellerate, retract flaps (maybe), all normal, autopilot may have been on
02:10 Engine fails at 1,300ft, pilots level off, airspeed decays
02:20 Wing stalls, aircraft drops 500 ft in 15 sec
03:45 Impact
I think the wing stalled in level flight after the engine failed. Maybe late going TOGA or MCT on the good engine. I think the aircraft remained stalled, or at least on the far back side of the power curve, until impact.
The crew were likely task saturated trying to secure a failed engine, turn away from terrain, and recover from a stall, almost simultaneously. Throw in GPWS alerts to add to the mix at the end. And we know from the final seconds of the video that this ATR can surely drop a wing in a stall, so the initial stall that lost them 500’ in 15 seconds may have well been similar. Very disorienting.
We all practice V1 cuts. Rarely do we practice engine failure in initial climb or in the cleanup phase, possibly in a terrain avoidance turn. My last airline had a sim scenario with engine failure at 700’ in IMC with the autopilot off. Much harder than a standard V1 cut.