Hi Pilots
I've never flown in a glider and only have Condor2 experience.
In a real glider is the COG adjustable in flight?
Would it be an advantage to be able to change this setting between thermalling, ridge flight and final glide?
Cheers Jeff
Centre of gravity adjustment
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Re: Centre of gravity adjustment
Not in flight. On ground you can.
Older models usually with lead plates added to the nose or a brass hub for the tailwheel instead of a plastic or aluminum hub. Most modern gliders have a tail tank which can hold 5 to 10 liters of water for CoG ajustments.
The advantage of a forward CoG is that the glider is more stable and less prone to spinning at the expense of control response. And aft CoG makes for a less stable more responsive glider, but it also spins more easily and is more difficult to recover.
There is also a small performance advantage of having a rear CoG. In normal flight the tail has to provide a downforce to counteract the pitch down tendency of the wing. With a more aft the CoG this pitchdown tendency is smaller so the tail has to provide less "negative lift". That means for the same weight the wing has to provide slightly less lift to offset this negative lift and you can fly at a slightly lower AoA and with less drag.
The control and spin behavioral differences are moddeled by Condor.The performance part I'm not sure, but I don't think this is.
Older models usually with lead plates added to the nose or a brass hub for the tailwheel instead of a plastic or aluminum hub. Most modern gliders have a tail tank which can hold 5 to 10 liters of water for CoG ajustments.
The advantage of a forward CoG is that the glider is more stable and less prone to spinning at the expense of control response. And aft CoG makes for a less stable more responsive glider, but it also spins more easily and is more difficult to recover.
There is also a small performance advantage of having a rear CoG. In normal flight the tail has to provide a downforce to counteract the pitch down tendency of the wing. With a more aft the CoG this pitchdown tendency is smaller so the tail has to provide less "negative lift". That means for the same weight the wing has to provide slightly less lift to offset this negative lift and you can fly at a slightly lower AoA and with less drag.
The control and spin behavioral differences are moddeled by Condor.The performance part I'm not sure, but I don't think this is.
PH-1504, KOE
Re: Centre of gravity adjustment
Thanks, I was having a hard time thermalling with half water ballast.
A friend suggested a CoG of -4 and that made my LS8 Neo glider more stable when thermalling and gave me better control.
As you mentioned it does mean that the top speed is decreased however not being able to thermal means the flight ends early.
I thought the green lever on the left-hand side was the CoG adjustment which could be moved just like the flap setting.
Cheers Jeffrey
A friend suggested a CoG of -4 and that made my LS8 Neo glider more stable when thermalling and gave me better control.
As you mentioned it does mean that the top speed is decreased however not being able to thermal means the flight ends early.
I thought the green lever on the left-hand side was the CoG adjustment which could be moved just like the flap setting.
Cheers Jeffrey
Re: Centre of gravity adjustment
The green lever is the trim. It adjusts the centerpoint of the elevator. If you put the CoG rearwards the elevator has less nose down authority (it needs some of it to keep the nose down). That means the maximum trimmed speed is lower. However if you push manually you should be able to reach Vne.
The green lever in the cockpit is not animated in Condor. You can see the trim setting in the lower right corner of your screen.
The green lever in the cockpit is not animated in Condor. You can see the trim setting in the lower right corner of your screen.
Last edited by wickid on Tue Nov 08, 2022 11:58 am, edited 1 time in total.
PH-1504, KOE
Re: Centre of gravity adjustment
I thought the trim was on the joystick somewhere as I had read about a spring-loading feature.
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Re: Centre of gravity adjustment
Yep that is called the trim. It doesn't change your CoG. It changes the center of the stick.
It is not animated in Condor but you can see the trim setting in the lower right corner of the screen. Default keys are Delete and Insert.
PH-1504, KOE
