Thread: Aft CG limit(s)
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  #4  
Old November 24th 03, 03:16 AM
Andy Durbin
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Judy Ruprecht wrote in message ...

Is it possible you're mixing apples & oranges?


The text of section 2.5 of the ASW-28 flight manual gives a center of
gravity range for flight of 222mm to 345mm. It does not relate this
limit to flight mass.

The flight manual also shows the flight mass vs CG envelope in
graphical form on page 5.10. It shows the aft cg limit constant at
345mm from 300kg to about 380kg. Note that 380kg is the maximum
allowed flight mass without water ballast. The aft limit then slopes
forward to about 315mm at 525kg. There is also a small forward
movement of the forward cg limit as flight mass increases. I believe
this diagram clearly shows a flight aft cg limit that is dependent on
mass.

I re-checked the ASW-19 manual and I did jump to the wrong conclusion
there. The data I looked at relate to empty mass cg as suggested by
Judy.

I don’t know why the aft limit moves forward with increasing
mass for the ASW-28. Could it be that Schleicher found the stall/spin
recovery characteristics unacceptable at max GW at the dry aft limit.

Would a 27 owner please say if that glider weight/cg envelope also
shows a variable aft limit.

Thanks

Andy (GY)