Minumum Sink Rate/Best L/D at 17,000 feet ?

On Jan 1, 2:14*pm, Eric Greenwell wrote:
kd6veb wrote:
I have never known anyone to use water ballast for a wave
flight. Now having said that it may be that having the wings full of
water might reduce flutter at high speeds which could be advantageous.

That's an interesting idea. I'm not aware of a discussion of on how
ballast changes the flutter characteristics, but it seems like the
differences might be substantial.


Yup - you would expect that increasing the mass of the wing would give
it a higher resonance frequency and therefore a higher flutter speed.
One interesting experiment would be to deflect the wings on the ground
and release them - with and without water - and measure the difference
in the frequency of the oscillations.

9B