The nautical terms above are what all mariners fear most…..an indication that two vessels are maintaining the same relative position to each other, but closing the distance apart. The results of that scenario, if it is not rectified, is pictured below. Many a great naval career has ended on this sad note. And it doesn’t have to be two vessels, just two objects like a ship and an iceberg. Poor Captain Smith of the Titanic would attest to that, were he still here.
When I was out taking some pictures yesterday, I happened to look up to see two planes seemingly on a collision course. I never really expected anything to happen, but the illusion was startling at first. As they closed on each other, I could see the separation, but it still seemed unnecessarily close. I wondered why they would have been routed so closely together, even though they were probably a 1000 feet apart.
It made me wonder how many commercial flights might be in the air over the U.S. at any given time. It turns out to be 7000 (http://www.faa.gov/air_traffic/briefing/), an example of which is pictured below.
Certainly gives one an appreciation for the air traffic control system doesn’t it? Of course, the amount of room to maneuver increases exponentially the higher one goes, but it still looks like you could walk across the tops of the planes in several places in this illustration. Sort of reminds me of a quote I once saw: “Man is flying too fast for a world that is round. Soon he will catch up with himself in a great rear end collision.” – James Thurber