Firefighting helicopter crashes while collecting water - GIF

[albertq]

A classic example of vortex ring state. This happens in helicopters when the rate of decent is higher than 400ft/min with little to no relative forward airspeed. The analogy would be similar to falling down your own downdraft. The quickest way to escape it is moving sideways using cyclic stick to move out of vortex air column into still air, but pilot must recognise symptoms early or there won't be sufficient altitude to recover.