Prevents uncontrollable up and down movement of the nose.

• A. Horizontal stabilizer
• B. Vertical stabilizer
• C. Airfoil
• D. Flaps

Answer: (A)

Pitch stability is achieved by surfaces at the tail that create a restoring moment when the nose starts to move. The horizontal stabilizer sits at the tail and is designed to hold the aircraft’s pitch in by providing a steady aerodynamic force. This stabilizing force resists nose-up or nose-down tendencies, helping prevent the nose from moving uncontrollably. The pilot can then fine-tune pitch with the elevator, which is the movable part on the horizontal stabilizer.

In contrast, the vertical stabilizer controls movement around the vertical axis (yaw), not the up-and-down movement of the nose. The airfoil is a generic term for a wing or blade shape that generates lift, not a dedicated pitch-stability surface. Flaps alter lift and drag on the wings and are used for takeoff and landing, not to stabilize nose pitch.