I've had about 5 total lockups, though can only remember details of 3:-
1) Whilst in Ostwind, killed lead Boston III in formation, at same time it dropped bombs and.... lockup.... presumed lockup on death.
2) In Typhoon, auto-takeoff.... lockup. No other aircraft sighted in area.
3) In P40E, came down vertical on airfield, vulched 109, lockup. 2 or 3 enemy aircraft in area.