what may be happing.??... external are speed changes turn into internal air speed changes (ie gusts of wind)for the first 20-30 min I thought the tunnle op (driver) was fiddling with the air speed but after a while when I could fly stable and hold heading I started noticing that this was happning only when it was gusty. Its quiite noticable to a shydiver but tunnle rats are more use to it and it dosent bother me so much anymore