Quote: "One tip, since you are doing a flying game, you will want to remove the gravity variable, and take out any parts of the example code that affect the position on the Y axis."
It depends on how realistic you want it to look, you may find that you need a gravity variable and then a lift variable simulating the wings affect when the plane is in motion, faster = more lift.
The variables get more and more as you want more realistic flight, air resistance, engine thrust etc. It all depends on how important the handling of the plane is, it may be that its not a high priority.