It's unknown how Sully would have performed without FBW protection. He significantly misread his airspeed. Why are we to believe that if he wasn't in a FBW a/c that he'd have read his airspeed better? If he'd flown a non FBW a/c, that didn't have AOA protection, he'd have triggered he stick shaker, and perhaps pusher, unless he'd lowered he nose and rudeced the AOA. At 150', or less, that would have generated an increased rate of descent that we can only speculate as to if he would have had enough airspeed, and AOA available, to reduce the increased sink rate prior to touchdown. IMO it would have been a much more difficult situation to handle.
Touchdown was at less than the desired pitch attitude of 11 degrees. But Airbus also didn't recommend reaching the pitch limited AOA at 150' either. If normal speeds had been maintained during the final segment of the glide there would have been enough airspeed to raise the nose to achieve more than 9.5% NU.
Learning point - slight excess airspeed might be a goal for a water ditching. It gives you the opportunity to choose to touchdown point with a slight degree of variability due to wave patterns or sea state. Wiith low airspeed/high AOA you basically have only one touchdown point.
Last edited by misd-agin; 20th May 2017 at 15:14.
Reason: "Learning point -" added