The purpose of aircraft wing dihedral is to achieve what effect?

The purpose of aircraft wing dihedral is primarily to increase lateral stability. When the wings are angled upward from the horizontal plane, this geometric feature helps the aircraft maintain level flight and resist rolling motions. If the aircraft experiences a roll due to turbulence or a turn, the wing that is lower will generate more lift and the higher wing will generate less lift. This differential lift naturally helps to return the aircraft to a stable flight path, ensuring that it remains balanced and more controllable during flight.

Lateral stability is essential for safe and effective maneuvering, especially in adverse conditions. In contrast, while increasing lift at low speeds, decreasing drag, and enhancing fuel efficiency are important considerations in aircraft design and performance, they are not direct effects of wing dihedral. The primary focus of wing dihedral is on improving stability and control within the aircraft's flight envelope.