# Ground Speed vs Air Speed

Discussion in 'Off-Topic Chat' started by nycmathguy, Aug 1, 2022.

1. ### nycmathguy

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Why is air speed faster than ground speed? This might be a physics question but I still would like to know. Thanks.

nycmathguy, Aug 1, 2022
2. ### MathLover1

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True airspeed is simply the speed at which an aircraft is moving relative to the air it is flying in. As such, it’s also the speed at which the air is flowing around the aircraft’s wings.

Ground speed, on the other hand, is the aircraft’s speed relative to the ground. One thing that should be noted here is that it’s its horizontal rather than vertical speed – an aircraft climbing completely vertically would have a ground speed of zero.

In other words, while airspeed is what determines whether there is enough airflow around an aircraft to make it fly, ground speed is what determines how fast an aircraft will get to its destination.

The relationship between airspeed and ground speed is fairly simple. Ground speed is simply the sum of airspeed and wind speed. What is this? If the aircraft is flying in the same direction as the wind is blowing, the aircraft experiences tailwind, and its ground speed is higher than its airspeed.

For pilots, both airspeed and ground speed are very important. While the first of those helps them make sure they are flying fast enough to take off, not to stall, and so on, the second one helps them figure out how long it will take them to get from one place to another.

On the other hand, if you are a passenger, you will only need to be concerned about the ground speed as that will tell you how fast are you flying from your origin to your destination – how fast you will be able to get to your meeting, meet your relatives, or do whatever else the reason for your travel might be.

MathLover1, Aug 1, 2022
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3. ### nycmathguy

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nycmathguy, Aug 1, 2022
4. ### HallsofIvy

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But it is NOT true that "airspeed is greater than ground speed"!
If an airplane is flying with a tail wind, the airplanes ground speed is the airplane's airspeed PLUS the speed of the air (wind) over the ground.

HallsofIvy, Sep 11, 2023
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5. ### e.jane.aran

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Does "MathLover1" always scrape his/her answers from elsewhere? ([KN Aviation])

(Is "MathLover1" another ID for "nycmathguy", which is why questions and answers follow each other immediately, with the "excellent answers" having been copied from the work of others?)

e.jane.aran, Sep 11, 2023

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