I was tracking my son's flight today and got this map of the airspace. I've seen various versions of this many times before and each time my reaction is the same - Gasp!
During business hours there are 9,000 to 10,000 airplanes in the US airspace. And look where they are concentrated - right on top of my head! FAA handles 15 million flights a year, 43,000 flights daily, and on an average 5,000 planes at one time. My mind is now properly boggled.
On the rare occasion we see another plane from cruising altitude, it is usually far away and at a different altitude. Quite contrary to the picture above.
I can't help but wonder: how do planes not run into each other?!
I visited the FAA website and learned that commercial aircrafts have the TCAS system to warn pilots and avert collision with another plane. Plus, air traffic controllers play a very important role in ensuring aircrafts maintain safe distance from each other and that the "flow" of planes in and out of airports is optimal. The direction of the wind determines how planes land and take off and how airplanes fan out into known "routes" that crisscross at different altitudes. Think of the sky as full of multi-level highways.
Two rules are at the heart of the planning: aircrafts have to maintain 3-5 miles of lateral separation (think parallel lanes) and 1,000 feet of vertical separation. Starting in the 1940s, navigation aids (radio towers) were built all across the country to guide aircrafts from point to point (which explains why the planes are"tracking" the southern border in the picture). Now these aging "Navaids" are being replaced by GPS technology which provides increased accuracy for managing the air space and delivers unprecedented efficiency and safety.
Satellite monitoring is ushering "Time Based Metering" which tells the FAA precisely where an aircraft will be at a specific point in time and also bringing forth technology to allow a plane to glide gently during landing as opposed to the old method of dropping and coasting and then dropping again. This is how air traffic controllers and FAA are able to manage thousands of airplanes in the skies and hundreds that simultaneously approach the larger airports.
I definitely felt a little better knowing about the planning and technology while I tracked my "Waldo".