Which feature improves the lateral stability of an airplane?

Which feature improves the lateral stability of an airplane?

• A. Dihedral
• B. Winglets
• C. Elevators
• D. Rudder

Answer: (A)

Dihedral is a key design feature of an airplane that significantly contributes to its lateral stability. When an aircraft has a dihedral angle, the wings are angled upward relative to the horizontal plane. This configuration allows the airplane to restore itself to level flight when subjected to lateral disturbances, such as turbulence or uneven loading. If one wing experiences an upward lift increase, it will rise while the opposite wing, having a downward lift decrease, will lower. This inherent characteristic creates a rolling moment that helps the aircraft return to level flight. Therefore, dihedral essentially acts like a stabilizing mechanism, helping to keep the wings level and the airplane on a steady course, which is crucial for safe flight operations. Other elements, such as winglets, elevators, and rudders, play significant roles in the overall stability and control of an aircraft, but they do not directly enhance lateral stability in the same manner as dihedral does. Winglets are primarily designed to reduce drag and improve fuel efficiency by mitigating vortex drag at the tips of the wings. Elevators control pitch, impacting an aircraft's nose up or down movement, while the rudder provides directional control, primarily affecting yaw.

Dihedral is a key design feature of an airplane that significantly contributes to its lateral stability. When an aircraft has a dihedral angle, the wings are angled upward relative to the horizontal plane. This configuration allows the airplane to restore itself to level flight when subjected to lateral disturbances, such as turbulence or uneven loading.

If one wing experiences an upward lift increase, it will rise while the opposite wing, having a downward lift decrease, will lower. This inherent characteristic creates a rolling moment that helps the aircraft return to level flight. Therefore, dihedral essentially acts like a stabilizing mechanism, helping to keep the wings level and the airplane on a steady course, which is crucial for safe flight operations.

Other elements, such as winglets, elevators, and rudders, play significant roles in the overall stability and control of an aircraft, but they do not directly enhance lateral stability in the same manner as dihedral does. Winglets are primarily designed to reduce drag and improve fuel efficiency by mitigating vortex drag at the tips of the wings. Elevators control pitch, impacting an aircraft's nose up or down movement, while the rudder provides directional control, primarily affecting yaw.