Currently the only way to maneuver your plane while in camera 5/the cockpit view is to click and hold on the screen/joystick mode, or to use UHJK. The former is hard to keep stable as keeping your mouse perfectly centered is next to impossible and UHJK is not good for primary controls (especially with planes that are sensitive and turn very quick)
There should be a way to enable Camera 3 maneuvering while in the cockpit view, so that you can actually take off, cruise, and land without having to leave first person or fight the controls (pretty much exactly like how first person flight in project flight is)