Title is pretty self-explanatory. As of right now, the crosshairs and missile targeting circle are only available in cockpit view. When people build very complex, very compact, or very detailed planes they often have to hide the cockpit somewhere that is not ideal for targeting.
A toggle switch for the in-game first-person cameras that activates the crosshair and targeting circle (while also disabling the cockpit's targeting systems) would solve this issue.
It would also make on-board defensive turrets and anti-air vehicles more feasible, allowing the guns and crosshairs to move independently of the vehicle's cockpit and direction of travel.
I understand that this may not be possible, especially if it conflicts with how the the AI handles targeting, but it would be nice to have.