Dihedral

Dihedral

 




Dihedral & Effect
Dihedral is a term which is used to indicate the upward angle of the wings or tail plane of a fixed-wing aircraft, relative to the horizon. Most commercial airliners we see on airports today are configured with upward angled wings, which helps them to confer longitudinal static stability to the roll axis (see picture on the right). Generally speaking, the dihedral angle is greater on low-wing aircraft, compared to similar high-wing aircraft.
Aircraft with dihedral wing configuration

A side effect of dihedral can be roll-coupling, the tendency of an aircraft to Dutch Roll. This side-effect of dihedral can be extremely unpleasant, and, if handled incorrectly or with excessive flight control input, can become a danger to the aircraft and its occupants.