Weather Wednesday: Why do planes fly so high?

Weather Wednesday

LANSING, Mich. (WLNS) — The next time you board a plane, you’re likely to hear the pilot say the cruising altitude is somewhere around 35,000 feet.

While this is incredibly common, why is it so high? As it turns out, there are several reasons for the typical cruising altitude.

The most effective reason for flying so high? Fuel efficiency.

The 30 to 40 thousand foot height is within the stratospheric layer of the atmosphere, which is just above the troposphere. The air is thinner at this altitude, creating less resistance on the aircraft and allowing it to burn less fuel.

So, why not go higher, where the air is even thinner?

Essentially, going to a higher altitude burns more fuel, so this altitude range strikes a happy medium between fuel efficiency while cruising and the fuel burned in reaching that altitude.

There are other advantages to flying this high. The troposphere is where most weather “happens”. For reference, a strong thunderstorm can see its cloud tops reach 30 to 35,000 feet. So, for the most part, flying at this height helps avoid any turbulent weather below.

It’s also helpful to fly at this height in the event of an emergency with the aircraft, it allows pilots much more time to address or fix an issue than if it were flying lower.

Another cool tidbit on cruising altitude: flights going westward are given an even-numbered cruising altitude, like 36,000 feet, while flights going eastward are given an odd-numbered altitude, like 35,000 feet. This is done to prevent planes from flying into one other.

So the next time you find yourself on a plane, you’ll likely be able to have a better understanding as to what exactly the cruising altitude will be, although it can fluctuate depending on the length of the flight.

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