This happened to me since Aerofly2, and I don't know what's behind it. Sometimes, almost always, after flying a couple of minutes, the screen brightness changes - usually it gets a bit darker. It does not seem to be related to changing heading and different sun directions/time of day. It just get a notch darker. When switching to another app, brightness there is as was before. Also, I did not experience this behaviour in other apps/games, just in Aerofly.
Did anybody else noticed that? Or this this something specific to the lighting model?