Let's say a plane is flying above a runway in straight line, and gust of wind hits the plane from side.
Do pilot need increase thrust to stay above runway and where is axis of rotation ?

It often said that all object rotate around c.g. does it mean that axis of rotation passes through plane c.g. or somewhere else?

My interest is from the view of an observer seeing this encounter standing under the plane - a view from a ground-based frame of reference.

  • 1
    $\begingroup$ What are you trying to get from the answer? Because the gust of wind will cause the aircraft to change it attitude but it will also change it speed vector. So there will be a combination of rotation and translation. The combination will not necessarilly scale linearly with the magnitude of the gust. And in which reference frame do you want to define this axis? The aircraft moves with respect to the earth and with respect to air. Do you want to define the axis in the aircraft frame of reference, the earth frame of reference or the air frame of reference? $\endgroup$
    – DeltaLima
    Oct 6 at 8:34
  • $\begingroup$ @DeltaLima ref. frame earth $\endgroup$
    – user628075
    Oct 6 at 10:22
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    $\begingroup$ "gust of wind hit plane from side" what does it mean from side? Suddenly the whole side surface? Only the tail? Only the nose? Is it an assignment? What's your opinion? $\endgroup$
    – sophit
    Oct 6 at 13:04
  • $\begingroup$ @sophit yes all surface $\endgroup$
    – user628075
    Oct 6 at 14:28
  • $\begingroup$ Adding thrust will cause the plane to rise. Pilots generally increase bank to hold against wind. But for planes with very long wings, there is a danger of wing tip strike. $\endgroup$ Oct 8 at 5:57

1 Answer 1


The aircraft doesn’t rotate around a particular axis, it will be blown downwind and will rotate, so you can choose any axis that’s meaningful to you. The centre of gravity might be useful in many cases.

  • $\begingroup$ plane change orientation so it must rotate around some axis $\endgroup$
    – user628075
    Oct 6 at 8:10
  • $\begingroup$ Relative to the ground, the axis will be a long way ahead of the aircraft and will move relative to both the ground and the aircraft, but this is unlikely to be useful to identify for any practical purpose. $\endgroup$
    – Frog
    Oct 6 at 20:11

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