Originally Posted by
Chuck Ellsworth
I guess we do not have the same ideas regarding judging height during landings on water, I see no reason that a pilot should not be taught to flare on the water exactly the same as on land.
I guess it depends on how accurately you can judge the height. I assume minimum sink in a C152 would be about 250-300feet/min or 2-3kt
Assuming that if you stall the aircraft and all lift disappears (which it doesn't), then stalling at 50' will give you 33kt vertical speed at the bottom. Stalling at 10' will give you 15kt.
Assuming typical-ish C152 numbers, you will arrive with 50% less total energy by stalling it on at 10', compared to minimum-sinking it on, however if you just consider vertical energy (is there such a thing?) it is 25x higher.
These would be upper bound figures, since the lift doesn't disappear instantaneously with a stall, so your vertical acceleration would be nowhere near 1g. If the wing continued to produce at least 0.5g lift during your flare and descent, then a 10' flare wouldn't reduce your final total impact energy all that much, but the 'vertical impact energy' would still be 12x than using minimum sink.
On the other hand, carrying the extra speed of a minimum sink ditching might increase the risk of a nose-over when you have fixed landing gear?
A