In flight, which factor most directly signals approaching stall?

In flight, which factor most directly signals approaching stall?

• A. Angle of attack approaching critical AoA.
• B. Airspeed dropping.
• C. Altitude increasing.
• D. Pitch angle increasing.

Answer: (B)

The most direct signal of an approaching stall is the angle of attack nearing the wing’s critical value. Lift is determined by AoA, and when it approaches the critical angle, airflow can no longer stay attached and the wing begins to stall. Airspeed dropping is a consequence of losing lift and isn’t the immediate cue that stall is imminent, because stall can occur at different airspeeds depending on weight, configuration, and gusts. Altitude changing has no direct relevance to stall tendency. Increasing pitch can raise AoA, but it isn’t a direct warning by itself unless AoA is approaching the critical value. So the direct indicator is AoA approaching the critical angle.

The most direct signal of an approaching stall is the angle of attack nearing the wing’s critical value. Lift is determined by AoA, and when it approaches the critical angle, airflow can no longer stay attached and the wing begins to stall. Airspeed dropping is a consequence of losing lift and isn’t the immediate cue that stall is imminent, because stall can occur at different airspeeds depending on weight, configuration, and gusts. Altitude changing has no direct relevance to stall tendency. Increasing pitch can raise AoA, but it isn’t a direct warning by itself unless AoA is approaching the critical value. So the direct indicator is AoA approaching the critical angle.