LS4 trim

[bagmaker]

Flying a club LS-4a last weekend, trying to trim for a sandwich break I couldnt get a smooth speed. I figure this is a balance issue, as we would rise to 65 knots then fall back to 45 then up again. I would be 95kg clothed, no extra gear. I tried different altitudes with the same result, although higher speeds smoothed the dolphin tendency a bit, I wasnt in that much of a hurry. What am I missing?

[Udo Rumpf]

If you fix the elevator, in your case a no flap glider, there will be only
one trim speed. With the shift of the CofG the trim speed changes
within a narrow range. Only in ideal conditions can the glider
maintain a fixed speed. Mostly it will speed hunt to find its equilibrium
All gliders should not have any divergent, in other words the speed
hunting should not get worse and should stabilize within a narrow
range. To experience a minimum speed excursion a CofG should be
in the middle range or a bit beyond, The cycles will either be shorter
and deeper with the CofG more forward and longer and flatter with
the CofG further back. The trim lever is used to set the "average"
speed at which those cycles occur.
Udo



"bagmaker" > wrote in message
...
>
> Flying a club LS-4a last weekend, trying to trim for a sandwich break I
> couldnt get a smooth speed. I figure this is a balance issue, as we
> would rise to 65 knots then fall back to 45 then up again. I would be
> 95kg clothed, no extra gear. I tried different altitudes with the same
> result, although higher speeds smoothed the dolphin tendency a bit, I
> wasnt in that much of a hurry. What am I missing?
>
>
> --
> bagmaker