What is the dihedral effect and how does it influence lateral stability in a sideslip?

• A. The dihedral angle reduces lateral stability; it causes Dutch roll
• B. The dihedral angle adds lateral stability; when sideslipping, differential lift induces restoring roll toward level flight
• C. Dihedral effect only affects vertical stability
• D. Dihedral effect is about wing sweep

Answer: (B)

Dihedral effect provides lateral stability. With wings angled upward from the fuselage, a sideslip creates a difference in how the air meets each wing. The wing on the lower side experiences a higher angle of attack and generates more lift. That extra lift raises the lower wing, reducing the bank, and produces a restoring roll back toward level flight. In short, the dihedral angle causes differential lift during sideslip, which tends to bring the aircraft back to level. It’s a lateral stability feature, not primarily about vertical stability or wing sweep.