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Old June 26th 18, 04:16 PM posted to rec.aviation.soaring
Dan Marotta
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Default Discus 2 Optimal CG location

Not familiar with Discus W&B, but I'll bet the gear height has nothing
to do with it since the instructions in the maintenance manual probably
give instructions for leveling the ship prior to weighing.Â* Therefore,
if the main gear is taller, the tail will simply be blocked up higher
for the proper level.Â* At least that's the way it's been done for all of
my previous gliders, none of them were SH.

On 6/25/2018 5:50 PM, wrote:
On Tuesday, 26 June 2018 11:22:10 UTC+12, Bruce Hoult wrote:
On Monday, June 25, 2018 at 3:35:29 PM UTC-7, wrote:
On Tuesday, 26 June 2018 09:29:27 UTC+12, Bruce Hoult wrote:
On Monday, June 25, 2018 at 1:19:00 PM UTC-7, wrote:
I fly my 2B about 90% aft empty, but often don't add much tail water when ballasted. Often no tail water, especially in wave. Lead and a brass tail wheel helps with that.

I've found the WB a little unusual though as you need to measure the arms. They are a little different to the manual. I wondered if the wheel is supposed to be jacked somehow during weighing. Does anyone have any ideas about that?
Are you measuring with the tail on the ground? The glider should definitely be in something resembling flying attitude, though how that is defined for any particular glider is outside the scope of general W&B instructions. The instructions for any particular glider will be in its maintenance manual.
Of course it is weighed in the correct SH specified attitude.

Then I didn't understand your "I wondered if the wheel is supposed to be jacked somehow during weighing". What does it mean?

It is sprung, so the question is whether the wheel measurement varies depending on the extension of the landing gear, state of the springs etc. The springs were also upgraded as part of the 2001 landing gear AD.


I haven't looked into it, but my wheel measurements are slightly different from the manual.


I have a recollection of someone suggesting the main wheel should be chocked to full extension. Whether that makes a difference ...


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Dan, 5J