Aileron Up Float
The BAC1-11 had (has) an aileron Anti Up Float cable circuit linking both ailerons to prevent the ailerons rising in flight.
I know of an occation in the early 1980's at Gatwick where this cable had not been tensioned correctly (about 70lbs instead of 125lbs if my memory is correct) and on a C of A renewal test flight the crew had a nasty shock when doing the stall/stick pusher tests, one wing suddenly dropped sharply. Presumably this was the outboard wing stalling because the aileron was high.
Are you sure your Convair ailerons are correctly rigged and tensioned?
Stay safe, Dixi.