Here is a simple airplane flying over a land. the camera connection is not bad. it follows the airplane and changes up-vector when the aircraft makes a round. The sample uses a height map for collision detection. when the airplane pulls down or goes through mountains the “oops” will appear on the screen.
This one is the oldest of my works based on DirectX7 API ( Retain mode ) with an unreadable code in Delphi.

Download: Airplane source