What Canadianbaken said has been true for some years now, but it depends on the era of combat aviation you're referring too. Today, In the West, the Air Operations Center [AOC, usually a Joint AOC (JAOC) or Combined AOC (CAOC)] plans out the whole activity in the Area of Operations (AO) on a 72 hour cycle called the Air Tasking Cycle (or Wheel of Death). Everyday a new cycle starts, so there are 3 cycles at various stages of planning and execution each day. The final product they produce is the Air Tasking Order (ATO). In real life, you are never alone in the air. Everything is planned, including your CAP direction of orbit altitude and controlling authority (most likely an AWACS, or ground CRC). Control in the real world is very tight unlike DCS where it's a freaking free for all like atmosphere...