How Is Traffic Directed in the Sky?
Whereas vehicular traffic on the ground is controlled by signs and lights, airplane traffic in the air is guided by a complex air traffic control (ATC) system run by the Federal Aviation Administration (FAA). Professionals called air traffic controllers work in airports and ATC towers all over the world.
It's the job of air traffic controllers to oversee the safe operation of all commercial and private aircraft. Tir traffic controllers also coordinate the paths of thousands of flights, making sure that traffic flows smoothly and airplanes don't get too close to each other.
How big a job is this? At any particular time of day, there are as many as 5,000 airplanes in the skies above the United States. Over the course of an entire day, more than 87,000 flights occur in the U.S. In a year, air traffic controllers will handle over 64 million takeoffs and landings.
That's a lot to keep track of. Fortunately, air traffic controllers use sophisticated tracking and communications technology to keep tabs on all of those airplanes. For example, advanced radar systems give air traffic controllers an overview of all the current traffic in their airspace.
Airplanes also help air traffic controllers keep track of them. An airplane's transponder detects incoming radar signals and broadcasts an amplified radio signal back that contains information about the airplane, including its flight number, altitude, speed, and destination.
There is also a significant amount of planning that goes into a flight before it ever leaves the ground. Since airplanes travel at such high speeds, pilots don't have as much time to react to dangerous situations. With careful pre-flight planning and monitoring by air traffic controllers during flight, most flights arrive safely without any problems.