Hey, here's an idea. Try upping in the same plane so he cant outrun you. If he flys in to the ack, try changing your target to someone who isnt running to the ack. I flew that thing last night for exactly that reason, was tired of them walking away from me. Nothing better than the panicked manuvering the gamers will do when he realizes "the game is up".
Oh yeah, love this game, love the WW1 addition to the game.