Certified Flight Instructor - Flight Instructor Airplane Practice Exam

As altitude increases, the indicated airspeed at which a given airplane stalls in a particular configuration will?

1. Remain the same as at low altitude.

2. Decrease as the true airspeed increases.

3. Increase because the air density decreases.

4. Become more variable with temperature changes.

The correct answer is: Remain the same as at low altitude.

As altitude increases, the stall speed of an airplane in a particular configuration will indeed remain the same in terms of indicated airspeed. The stall speed is primarily a function of the aircraft's weight and its configuration (e.g., flaps extended or retracted). What changes with altitude is the air density, which affects true airspeed. As altitude increases, air density decreases, leading to a higher true airspeed at which the airplane will actually stall. However, indicated airspeed—that is, the reading on the airspeed indicator—remains consistent for a given configuration and weight of the aircraft regardless of the altitude. This means that pilots can rely on the same stall warning at any altitude, as the indicated stall speed does not change. This concept is critical for pilots to understand, as they must be able to recognize stall speeds through the instruments they are trained to use, ensuring safety and consistent handling characteristics of the aircraft in various altitudes.