Why does load factor increase during a turn?

The correct reasoning involves understanding the relationship between lift, weight, and the forces acting on an aircraft during a turn. In a turn, the aircraft must generate additional lift to counteract the horizontal component of the lift vector that is required to change direction. This additional lift is necessary to maintain level flight while banks occur, which leads to an increase in load factor.

When an aircraft is in a banked turn, the lift vector tilts, creating a horizontal component that pulls the aircraft toward the center of the turn. Because the total lift must equal the total weight plus any additional forces acting on the aircraft, the increased lift requirement results in a higher load factor.

While centrifugal force is often referenced in discussions about turning, it is important to note that it is not a distinct force acting on the aircraft but rather a result of the aircraft's change in direction. The change in load factor does not arise from changes in aircraft weight; instead, it is a product of the increased lift requirements needed to maintain altitude during the turn. Thus, the recognition of increased lift requirements during turns is the key reason why load factor increases.