Ronald writes:
>Should I get the time to cross 100' in calm
wind?
Get the time to cross with the least altitude
lost.
Let's say the model loses 5 feet in 100 at 25
mph.
that would be:
20:1 Lift/Drag (L/D) @ 25 mph (best L/D speed)
The equation to figure out how far you can go
(penetrate) into a headwind is:
(L/D)*(LDspeed - headwind speed)
-------------------------- = actual L/D
( L/D speed )
Actual L/D is the models glideslope into a given
wind. You want the biggest number you can get.
Wing loading will raise the best L/D speed, so
try to test models at similar wing loadings.
You want a model with a high best L/D speed at
the lightest wing loading, which would indicate
that the model will be less sensitive to wind
effects at a given loading. (play with the above
equation to get a feel for this.
Beware selecting a model based primarily on
optimizing one variable. Unless of course it
launches the highest.
I would love to see some numbers on this!
John Roe
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