What is the function of the horizontal stabilizer?

The horizontal stabilizer plays a crucial role in maintaining the pitch stability and balance of an aircraft. It is positioned at the tail and works to counteract the pitching moments created by the aerodynamic forces acting on the aircraft, particularly during flight maneuvers. By providing a downward aerodynamic force, the horizontal stabilizer helps keep the aircraft in a straight and level flight path, ensuring smooth and controlled ascent and descent.

This stabilizing force is essential for maintaining the desired angle of attack, which directly affects the aircraft's lift and stability. If the aircraft were to become nose-heavy or tail-heavy, it could lead to an unstable flight condition; thus, the horizontal stabilizer is vital in ensuring a balanced and stable operation in the pitch axis.

The other options pertain to different aspects of aircraft function. Yaw stability and direction is managed by the vertical stabilizer, while lift increase during takeoff is related to the wings and certain flight configurations. Fuel distribution management is not a function of any aerodynamic surfaces but rather pertains to system design and operation.