Hi everyone,
Wow, thanks for all the replies, this is great. I don't mean to grumble, but the replies are a little along the lines of "this is practically impossible" and less along the lines of "assuming this is almost possible, how can we get as close as possible to it?"
. . . if a plane's forward speed is reduced to zero, its wing stops generating lift and it gains velocity downward resulting in a crash . . .
Yes, absolutely. Which is why I rephrased the questions as:
What's the theoretical lowest landing speed?
What could you do to push this towards zero?
What's the theoretical lowest perch for landing at zero speed?
What could you do to push this towards zero?
It's surely possible to do a pretty low speed landing, if you're a good pilot. You could do a slower one if the plane was designed with low speed landings in mind. I bet it's possible to do an even slower one if you could have superhuman reflexes, and lots of sensing. You could maybe push it really close zero if the wings could make one hard flap just as it came into land. Maybe it could take advantage of ground effect for a little extra lift? Maybe this could be slow enough that the feet could grip the ground / perch and bring it to a full stop.
This is going to take some very good reflexes and familiarity with the craft.
In fact, I think it would be impossible for me personally to do it. Which is why it needs to be an automatic, computer controlled landing.
In effect they don't fly to a landing so much as superstall their way to zero airspeed and do it all with grace and balance.
Yes, brilliant, This exactly what I'm imagining. The plane would need to dump all of its kinetic energy in a controlled manner, riding very close to having an accident, but using sensing and computer control to keep it stable.
A bird's wing has camber like an airplane's wing, but this camber can be affected by the bird's muscular movements. The angle of attack of the bird's wing is also highly variable depending on muscular movements.
Yes, it would be awesome to make wings which can alter their shape like a bird's wing. I think this is more feasible than flapping, because it requires a hell of a lot less power. I'd love to make a wing like that.
Altering the wing isn't hard but I think you'll find that programming in the responses will be extremely tough.
Yes. But what I was thinking is that it could learn. You get it to do landing after landing, all day, each time it tweaks its parameters to bring the landing speed closer and closer to zero. Trying to program it and get it right is practically impossible.
I will take a look at the book "Model aircraft Aerodynamics" over the weekend.
Some more questions:
What do you think the wing should look like during the "super stall"?
How could it tell if it was making the perfect stall? i.e. what sensors would it need? Is the wing load/torque/angle an important factor?
Many thanks for all your help
Hugo