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Gyroscopic effect

 Gyroscopic effect

  • The rotating mass of the propeller or the compressor in the case of a jet engine may cause a slight gyroscopic effect.
  • A rotating body tends to resist any change in its plane of rotation, and if such change does take place there is superimposed a tendency for the plane of rotation to change also in a direction at right angles to that in which it is forced.

  • This can easily be illustrated with an ordinary bicycle wheel; if the wheel, while rapidly rotating, is held on a horizontal shaft and the holder attempts to keep the shaft horizontal while he turns, the shaft will either tilt upwards or downwards according to whether he turns with the opposite or the same sense of rotation as that of the wheel.
  •   Thus if the propeller rotates clockwise when viewed from the pilot’s cockpit (the usual method of denoting the rotation), the nose will tend to drop on a right-hand turn and the tail to drop on a left-hand turn.
  •  It is only in exceptional cases that this effect is really appreciable, although it used to be very marked in the days of rotary engines when the rotating mass was considerable.

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