I believe a better wording of this would be
as a move and standard action you can move your full fly speed and make a single action along that path,
pending the fly check of course. Which keeps you for making a huge angle change in midair to fly back the way you came.
Since the benefit of it lets you make a move action and than another standard (the attack) and then finish your move.
But you can not double or triple move in that move action.
I find it easier to think of it like a swoop attack. Swift action optional, Move Bang Move, done.