how the airplane traffic is structured. Is it more like a highway or is it more like a railway?

Question

In a highway, any car can enter and is flexible to switch lanes and the coordination between cars is mostly a responsibility of the drivers. In the railway everything is pre-routed and no surprises are technically possible — dispatchers and planners have more control than the train driver and there is no room for flexibility — you just stay in your rails. What is air like? Can I build my own plane and just join the air traffic without telling anyone?

In: 4

Answer 1

It depends. There are a lot more “lanes” in the air then on the railway, or even highways. So the basic rule is that airplanes can go anywhere they like as long as they do not crash into each other. But it is a good practice to call out on the radio telling everyone where you are.

However that does not work for areas of high congestion such as around cities and airports, at higher altitudes where airplanes go too fast to see others before it is too late, or in bad visability such as clouds, fog or rain. So in some areas any pilot needs to talk to an air traffic controller before entering and while manouvering. There are different classes of airspace and different types of flight following. Sometimes the air traffic controller just tells the airplanes about other airplanes nearby and other times the air traffic controller is telling the pilots exactly where to go. However the pilot is still ultimately responsible, normally the pilots will tell ATC where they want to go and the ATC will tell them how to get there.

For places of extremely high congestion though, such as runways and certain air coridors, there is a need to ask permission. And there might be a long queue to get this permission. So before any flight the pilot will file a flight plan and get slots assigned. That means they need to be at the certain place at the certain time to avoid overcrowding. This is to prevent situations where all airplanes come to the same airport all at once wanting to land so everyone have to circle for hours. One of the most crowded air coridor is the transatlantic flight coridors which are places that due to weather conditions that day is the optimal way to fly across the atlantic. And because of the long distances without radar coverage or good ATC communications airplanes have to be quite far apart which does not help.