Right, mystery solved...except the answer just poses more questions. Some bearings in the aileron bell crank had corroded and gone completely solid! The engineer had never seen such a thing happen before. The scary thing is that apparently it could have happened at any time, and IN ANY POSITION OF THE AILERON. Can you imagine if it was in a turn?

I've no idea what you'd do under those circumstances; I guess full opposite rudder, and try and keep some sort of control until you can find a reasonable place to land.
But anyway, that didn't happen. The engineer has suggested replacing the bearrings in both ailerons, and it seems a good idea...but expensive. So Paul is hoping to pick up KF on Saturday, or next week, and is looking for an aerial lift (free or inexpensive cost sharing) from Sleap to Kemble. Would anyone fancy the trip? Paul doesn't have internet access right now, but says if anyone can help, please give him a call on 07795 965845. Or pm me if you prefer. If nothing else, the restaurant at Kemble is worth the trip.