Which statement about stall onset is correct?

Which statement about stall onset is correct?

• A. It is primarily a function of angle of attack.
• B. It is solely a speed phenomenon.
• C. It cannot occur below a certain speed.
• D. It requires engine failure.

Answer: (B)

Stall onset is governed by the wing reaching its critical angle of attack. When the angle of attack becomes too large, the airflow can no longer stay attached to the lifting surface, causing flow separation and a rapid loss of lift. This means that the key factor is how the wing meets the air, not just how fast the airplane is flying. Speed matters because lift depends on dynamic pressure, so in level flight your stall speed (the minimum speed to stay aloft) tells you where you’ll reach that critical angle in practice. But you can reach stall conditions at different speeds depending on weight, config (flaps, clean or dirty), and load factor. The idea that stall onset is purely a speed phenomenon is incomplete because the same high angle of attack will cause stall regardless of speed, and factors like maneuver load can change the speed at which stall occurs. Stall can occur without any engine failure, and it is not correct to say it cannot occur below a certain speed—stall can happen at higher speeds in turns or gusty conditions if the wing exceeds its critical angle of attack.

Stall onset is governed by the wing reaching its critical angle of attack. When the angle of attack becomes too large, the airflow can no longer stay attached to the lifting surface, causing flow separation and a rapid loss of lift. This means that the key factor is how the wing meets the air, not just how fast the airplane is flying.

Speed matters because lift depends on dynamic pressure, so in level flight your stall speed (the minimum speed to stay aloft) tells you where you’ll reach that critical angle in practice. But you can reach stall conditions at different speeds depending on weight, config (flaps, clean or dirty), and load factor. The idea that stall onset is purely a speed phenomenon is incomplete because the same high angle of attack will cause stall regardless of speed, and factors like maneuver load can change the speed at which stall occurs.

Stall can occur without any engine failure, and it is not correct to say it cannot occur below a certain speed—stall can happen at higher speeds in turns or gusty conditions if the wing exceeds its critical angle of attack.