In aeronautics, the relative wind is the direction of movement of the atmosphere relative to an aircraft or an airfoil. It is opposite to the direction of movement of the aircraft or airfoil relative to the atmosphere. Close to any point on the surface of an aircraft or airfoil, the air is moving parallel to the surface; but at a great distance from the aircraft or airfoil the movement of the air can be represented by a single vector. This vector is the relative wind or the free stream velocity vector.
The angle between the chord line of an airfoil and the relative wind defines the angle of attack. The relative wind is of great importance to pilots because exceeding the critical angle of attack will result in a stall, regardless of airspeed.
Read more about Relative Wind: Relative Wind in Freefall
Famous quotes containing the words relative and/or wind:
“It is an interesting question how far men would retain their relative rank if they were divested of their clothes.”
—Henry David Thoreau (1817–1862)
“Once in this wine the summer blood
Knocked in the flesh that decked the vine,
Once in this bread
The oat was merry in the wind;
Man broke the sun, pulled the wind down.”
—Dylan Thomas (1914–1953)