That won't work because it would severely affect mission balance - you can't plug-and-play it, since most missions are designed with certain flight mechanic limitations in mind, and changing it may have rather unforeseen circumstances. It would require at the very least a test run to make sure that no mission breaks, and to tweak and fix the ones that do.
Not something purely on the UI side like a cockpit mod or radar icons which only affect what you the player sees and not how the game itself is operating.
If you look at the RealFlight mod, it says:
Note that missions (espacially retail FS2 ones) will become imbalanced due to the changes this mod makes.
Basically, you'd have to tweak or build missions from scratch with the flight mechanic in mind, or you might get some rather wonky behavior with the AI and balancing and such.