Why do commercial planes fly at 35,000 feet?

Question

Why do commercial planes fly at 35,000 feet?

In: 13

Answer 1

It’s kind of the sweet spot between getting enough air to react with fuel in the engines and reducing drag.

Air gets thinner as you go higher. Too high and your engines work inefficiently or not at all due to lack of oxygen. Too low and you’re fighting more air resistance than you need to. 35k feet or so is the goldilocks zone – just right for cruising altitude.

It also happens to be high enough to avoid most weather, so you only have to deal with turbulence/bad weather on approach/landing/takeoff.

Answer 2

It’s kind of the sweet spot between getting enough air to react with fuel in the engines and reducing drag.

Air gets thinner as you go higher. Too high and your engines work inefficiently or not at all due to lack of oxygen. Too low and you’re fighting more air resistance than you need to. 35k feet or so is the goldilocks zone – just right for cruising altitude.

It also happens to be high enough to avoid most weather, so you only have to deal with turbulence/bad weather on approach/landing/takeoff.