F3 for external
F4 for chase
F5 for .....ummm.....a "NORTH ORIENTED VIEW"????
In each of these and also whilst you are in cockpit:
F7 for Snap view: Your head turns (rather quickly) to the required position
F8 for Pan view: You casually cruise around enjoying the scenery
F9 for Instant views: No wasting time, your head immediately points where you want it to!
Hope that helps.......
Personally, I dont like panning and mouse views though.