AirScotia:
My physics is rusty, but isn't velocity a product of speed plus direction? A spinning aircraft may not have forward speed, but it does have plenty of changing direction, therefore plenty of velocity. So it will hit the ocean with plenty of energy, I assume?
Linear velocity has a speed and direction component, but they aren't involved in a product that says something about the energy of the system. That would be speed and mass.
Rotational velocity - the rate at which a body is spinning about an axis through its center of gravity - also needs a mass component and its distance from the spin axis to form "angular momentum", which would indicate how badly impacting a fixed object (e.g. the water surface) would damage the rotating body. The accident-investigation experts can pontificate re any signs that occurred here.