You might want to look at the aircraft mod in how they handle their airplanes so that it can actually function as a plane instead of an over sized car

Sorry for the late reply, I didn't get a notification for this :/

From what I see, in the aircraft mod the planes are basically a reskinned tank without collision.
I've gone with a more realistic and fun (in my opinion) approach for this mod, just like the aircraft mod with the aircraft realism mod added, so you can not turn while standing still and you need to be above a certain speed (160 km/h by default, configurable in the mod map settings) to become airborne.

I hope this clears things up, if you have any feedback or bugs to report, feel free to do so!
Thanks for playing my mod! :)