Quote:The problem with trying to use a R.A.T. to get more juice while in the air is that, while you get juice, it creates more drag.
So more drag, just to get more thrust, but with some loss in between, it is a negative gain.
Right. Overall, it's a matter of simple entropy, a law that has yet to be broken.
An airplane that charges itself as it flies (due to its movement, not solar or some onboard powerplant not involved in thrust)) is a perpetual motion machine... and even armchair engineers know that there ain't no such thing as a free lunch!
A RAT on an electric airplane would help in charging a separate system, for lights, radios, etc... but it would not be able to make a difference in the power/thrust/drag equation.
Energy storage (batteries) is the big problem right now, due to weight and space, but it's improving.
Lithium-ion packs are leading the way, and the next big idea- batteries that store latent energy using a gas instead of fluid, gel or metals... is being explored.
And electric planes are already flying...
The Yuneec is looking quite viable, for short flights, anyway, and Sonex is making good progress with the electric-powered version of their popular kitplane. And there are several self-launching gliders already that make good use of very modest electric-power systems.
It's too early to say "practical sustained electric flight is not possible because of weight!" ... remember, people said the same exact thing about the use of internal-combustion gasoline engines for heavier-than-air flying machines before
that was proven wrong!!
and when you look at the first Wright Flyer, you see that it was couldn't perform much better (even putting aside the high-drag, antiquated design) than any electric airplane flying today. Less so, in fact. Its powerplant was pretty weak, and it could not carry much fuel at all.
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