I wish I could have seen the last 10 seconds prior to the aircraft entering the water.
In a US helicopter, an engine failure might result in a left yaw. This one yawed right, but I suppose that could be because Russian helicopter rotor systems turn in the opposite direction.
I am not sure if the aircraft is designed for a water landing, as it appeared to "porpoise" in the pitch axis while on the water. The water went up *over* the fuselage... I am not certain that is normal.
Then it appeared to over rotate for takeoff (crew induced... could be a result of whatever was causing it to porpoise earlier), resulting in the rotor contacting the surface.
Maybe the overrotation was exagerated by the aircraft taking on water from the hard landing, and shifting the longitudinal CG forward?
My guess: The pilot felt that they would sink if they stayed there, but knew they were power limited (single engine), so attempted an "airspeed over altitude" takeoff in order to compensate for the power loss, but experienced an overrotation of the main rotor caused in part by the CG shift of the water that was taken on at the beginning of the incident (and was also the cause of the decision to fly it out).
I am encouraged that the aircraft floated. Getting out of an inverted, ditched helicopter sucks, especially while sinking. The Navy has a dunker trainer. It is a significant emotional experience (they blindfold you for that one, and the guy in front of you always manages to kicked you in the face on the way out... every time). But the alternative is worse. A modern attack helicopter reaches an unsurviveable depth within 30 seconds. Get out quick or go visit davy jones' locker.
<yawn>
Villa
<edited when i remembered that russioin rotor systems turn the other way.>