Have you ever watched the moving map on a flight? If so, you’ll have observed that the height at which you fly changes from flight to flight. If you’re super observant, you may have noticed that on longer journeys, this height changes a few times during the flight. But what dictates how high you fly? And why does this often change during the flight?
Height, Altitude and Flight Level
First, let’s differentiate between some technical terms. Two of which you will have heard of, the other, you may not have. Even though height and altitude are easily interchangeable in common language, there’s actually quite a difference between the two in the aviation world.
Height refers to the vertical distance of an object above the ground. The structure of the Air Traffic Control tower at Heathrow Airport has a height of 285 feet. This means that the distance an object would fall if you were to drop it off the top would be 285 feet. Pretty obvious.
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