How many commercial flights take off in the United States each day?

I'll build this up from airports. I'll put them in three size groups, estimate departures for each, and add them up. Start with the big hubs. There are about 30 of them, with about 500 departures a day each, so that's 15,000. A big airport runs about 18 hours a day. One takeoff every two minutes is 30 an hour, or 540 a day, and I'll round down to 500. Then about 70 mid-size airports with about 100 departures a day each, which is 7,000. That's a takeoff every ten minutes or so. Then there are maybe 300 small airports with about 10 flights a day, which adds 3,000. I'm less sure of the count there, but it's the smallest piece. So in total that's about 25,000 flights a day. That seems plausible to me.

I'll build this up from airports. I'll put them in three size groups, estimate departures for each, and add them up. I'm counting scheduled passenger flights and leaving out cargo and private planes. Start with the big hubs. There are about 30 of them, with about 500 departures a day each, so that's 15,000. A big airport runs about 18 hours a day. One takeoff every two minutes is 30 an hour, or 540 a day, and I'll round down to 500. Then about 70 mid-size airports with about 100 departures a day each, which is 7,000. That's a takeoff every ten minutes or so. Then there are maybe 300 small airports with about 10 flights a day, which adds 3,000. I'm less sure of the count there, but it's the smallest piece. So in total that's about 25,000 flights a day. Let me check that against passengers. At about 100 passengers a flight, 25,000 flights carry 2.5 million people a day, or roughly 900 million a year. That's a bit under three flights per American per year. Most people fly less than that, but frequent flyers and visitors pull the average up, so it holds together. The number I'm least sure of is the 500 for hubs. The very biggest airports do about twice that and the smaller hubs about half.