REFLECTOR:CG Test

John Dibble reflector@tvbf.org
Fri, 23 Jan 2004 21:36:55 -0600


I decided to do a test to determine my aft cg limit as suggested by 
Scott B.  My balance calculations for my SRG indicate I will be aft cg 
with less than 250 lbs in the front seats.  I weigh 170 so this needs to 
be resolved and nose weight added if needed.  I put 8 x 10lb weights in 
the copilot seat.  At 7500' I trimmed for 75-80kn and pulled back until 
the canard stalled at 60kn.  It took all the aft stick and I had to trim 
to about 70kn in order to stall the canard.  The canard motion was 
gentile and the plane was a bit wobbly, but stable.  One-by-one I moved 
the weights to the rear seat and repeated the stall.  Each time the 
canard motion was less pronounced.  With all the weights in the back 
seat the canard just kind of mushed down at 58kn.  In all cases I had to 
maintain aft stick pressure to get slow enough to stall and never had to 
push the stick forward.  I should add that I have 3 leading edge 
vortilons and one trailing edge fence inboard of the aileron on each 
wing.  So it appears that I do not need to add any nose weight.  Anyone 
agree/disagree?

John