When flying in real life, you have to file your flight plan with the ATC/FIC before you fly.
The ability to plan your flight before you leave an airfield is a great planning tool. But what if it's not a mission? Just a flight route you wanted to take? Or how about it you're squad leader, to assign flight plans to your squad mates for patrols...but not missions. So in essence it's like a mission planner, but it's something you can just bring up and assign to a pilot who either accepts or rejects. It then appears on your clipboard and you can flight the route...like a patrol.
Some will say - it's a mission! But what if your guys are already in the air and you just want to assign friends/squadmates the route you're going to fly? Would work for vehicles and boats too no?
Just a thought.