Take advantage of the other players greed. That is the P38 is always a favorite target so the red guy often throws away advantages just for a shot at the big plane. In desperation, with a high speed attacker again take advantage of their greed with dumping your speed as late as possible then roll around for the overshoot.
If caught low and slow look for a tight area to fight in as the 38 works well in tight spaces suitable for the 38 at slow speeds.
