>1) You need to implement it for very small airplanes too, which is far from easy. No, you don't. It's easy: just don't allow small airplanes at airports with

>1) You need to implement it for very small airplanes too, which is far from easy. No, you don't. It's easy: just don't allow small airplanes at airports with large commercial aircraft. No one needs them anyway; they're just a luxury for rich people. The only place they make sense is for very remote locations, like Alaska, where there's a need for people to pay for carriage on such a small aircraft. For normal airports that carry jumbo jets, there's no reason to have small planes sharing the runways. For exceptions like coast guard jets such as this one, these are government-owned so they can afford the upgrades.