The angle of attack at which an airplane wing stalls will

• A. Remain the same regardless of gross weight
• B. Increase with gross weight
• C. Decrease with gross weight
• D. Vary with airspeed

Answer: (A)

The angle of attack at which a wing stalls is determined by the wing’s lift characteristics, not the airplane’s weight. Stall happens when the lift coefficient reaches its maximum (Cl max) for the given airfoil and surface condition, which occurs at a particular angle of attack. That critical angle is roughly constant for a given configuration, so the stall angle of attack doesn’t change with gross weight.

Weight affects how fast you must fly to reach the needed lift in level flight: heavier airplanes require a higher true airspeed to generate enough lift, so stall occurs at a higher speed, but at about the same angle of attack. The idea that stall angle would vary with weight gets it backwards; the same AoA can cause stall across weights, with speed shifting to meet the lift needed.