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Dihedral angle

Dihedral Angle

  • The dihedral angle is have a big advantage like is make lateral stability on the planes, and is defined as the angle between each plane and the horizontal, the meaning of a dihedral angle if the planes are inclined upwards towards the wingtips.
  • dihedral is positive but if is downwards it is negative then called anhedral, and is used in practice for the reason of dynamic stability.
  • Sometimes The effect of the dihedral angle in securing lateral stability is dismissed by saying that if one wingtip drops the horizontal equivalent on that wing is increased and therefore the lift is increased, whereas the horizontal equivalent and the lift of the wing which rises is decreased, and the forces tend to right the aircraft.
  • When aircraft stop rolling and provide that is still traveling straight ahead , the aerodynamic forces will be influenced by airstream passing over the plane, this will apply for both wings.
why a dihedral angle is an aid to lateral stability?
  • The lift on the wing vertically upward and balance the weight when both wings are equally inclined, but if one wing is lower than the other is make the lift on the wings slightly inclined in the direction of the lower wing, while the weight is remaining vertical there are two forces that will not balance each other and will be small result force acts in a sideways and downward direction.
  •  This unbalanced force and therefore the airplane will move in the direction of this force and  will A sideslip and may this cause a flow of air in the opposite direction to the slip and have the effect of increasing angle of attack and increase that on the upper plane.


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