Flat Spin Recovery?
Deploy the spin chute. Don't have one? Well, there are a few things you can try with the engines to break the spin but they've probably all flamed out or are stalling due to the inlet conditions in a flat spin. So recovery is very unlikely. However, my understanding is that they hit the water nose high and wings level with a high sink rate and minimal yaw. That suggests an upset into a high-speed spiral dive with a recovery in progress when they ran out of altitude, rather than a flat spin which would result in a completely different water entry.