Dont listen to the people complaining about a difficulty spike, there isnt one, much less on rookie. I just played through four campaigns with only the starter plane and only died to a triplane with heavy firepower.
You might get shot down a few times in rookie, sure, but if your entire squadron is getting shot down on rookie, something. Is. Seriously. Wrong with your gameplay strategy. Either 1: instead of thinking ahead about what the enemy might do and denying him the chance to get behind you, you for what ever reason, turn and let him get behind you, thinking it will be okay because its on rookie. Or number 2: you for some reason thought it would be better to get a bunch of other moves instead of getting an Immelman or some other kind of 180 degree evasive maneuver. Or finally number 3: You just need more practice, because you might not yet understand the way the physics and grid work.