In Aces High II, you can use your mouse instead of your joystick or keypad keys to look around while you are in flight. To set up your mouse view options in Aces High II, select Options->Preferences->View Options from the clipboard menu.
Default to Instant View will automatically switch you to mouse view when taking off in an aircraft, vehicle or boat. Shift-M toggles the mouse view on and off, but if you've made any changes to your key maps, you'll have to use the Key Mapping utility in Aces High II to map Shift-M before trying to toggle the mouse view while in flight.
Start in Mouse Look is the initial state when you enter a plane or vehicle.
Mouse Snap Views works like the view system, when you move your mouse so far, you will snap to another view. Unchecking this options switches you to pan mode.
Invert X and Invert Y will switch the respective axis for your mouse movement in Aces High II.