uwish uwish:
he was clearly in a wing level stall (nose up) early in the video (from what cause who knows) then my guess is he tried avoiding the bridge but when your stalled any control input from the wings (aileron) can result in a sudden wing drop in either direction.
That is exactly what happened, they will have to determine what caused the loss of power as it appears his props were simply feathered.
![Drink up [B-o]](./images/smilies/drinkup.gif)