Which of the following situations leads to a decreasing stall speed (IAS)?

The situation that leads to a decreasing stall speed (Indicated Airspeed) is indeed related to decreasing weight. When the weight of the aircraft is reduced—whether due to fuel consumption, unloading cargo, or a reduction in passenger count—the aircraft requires less lift to maintain level flight. Since stall speed is the minimum speed at which an aircraft can maintain controlled flight before entering a stall, it is directly affected by weight.

As weight decreases, the aircraft can achieve the necessary lift at lower speeds because the aerodynamic forces acting on the aircraft are altered. Specifically, with a reduction in weight, the lift-to-weight ratio improves, and the critical angle of attack at which stall occurs remains the same. Therefore, the stall speed decreases. This principle is particularly significant during flight operations, as pilots must be aware that a lighter aircraft can stall at a slower speed compared to a fully loaded one.

In contrast, increasing air density would generally result in an increase in stall speed, as the aircraft would require more lift at the same angle of attack. Increasing load factor, such as during turns, increases stall speed due to the greater lift required to counteract the increased weight experienced in a banked turn. Similarly, increasing altitude, where air density decreases, typically leads to higher