There has always heeb a shortage of decent landing strips in SA. Roads were usually the best bet. But with constant traffic you usually ended up damaging the aircraft or having real problems getting going again
They seem to have though of this a little with some of the rocket craft and vtol but it's still a problem. Landing the glider is a pain even on a flat runway. You need tons of space and no bumps at all.
My main point is that with the map and the constant amount of barriers everywhere I think this is a reason why there have always been so little air travel in the game. YYou rarely see people flying, even on such a large map. Simply because most heli's are reall slow and painful when climbing and there are only four actual airstrips in the map, one of which will get you a lazer high five for making the attempt.
I think simply things like the ability to deploy an aircraft parachute when landing so that the vehicle will come to a rapid stop would increase the usability of these aircraft.
After all, spending several million on a plane that you have almost nowhere to land is pretty severe.