At the end of the movie, when bad guy and Frank fight in the airplane, bringing it down to crash into the water, you can see the cockpit windshields breaking and the water flooding the plane, in the next shot Frank is turning around and jumping to the tail of the airplane, away from the water.

Like any other material in this world, Frank is not immune against the effect of inertia, so in the above situation, he would be hammered into the cockpit or the water, but not thrown in the opposite direction.