THE PILOT OF THE ACCIDENT AIRPLANE STATED HE WAS PERFORMING A POST MAINTENANCE TEST FLIGHT. AFTER HE BECAME AIRBORNE HE PULLED UP TO EXECUTE A 'SPRAYER'S TURN.' THE PILOT TOLD AN FAA INSPECTOR THE AIRPLANE SHUDDERED APPROXIMATELY ONE-HALF THROUGH THE TURN. THE PILOT REMEMBERED APPLYING HARD RIGHT RUDDER, AILERON AND FULL AFT ELEVATOR BEFORE IMPACTING THE GROUND.