Certified Flight Instructor - Flight Instructor Airplane Practice Exam

What does the lower limit of the white arc on an airspeed indicator represent?

1. Minimum controllable airspeed with flaps extended

2. Poweroff stall speed in a landing configuration

3. Poweroff stall speed in a specified configuration

4. Minimum airspeed for maneuvering

The correct answer is: Poweroff stall speed in a landing configuration

The lower limit of the white arc on an airspeed indicator represents the power-off stall speed in a landing configuration. This speed is critical for flight safety, as it indicates the lowest speed at which the aircraft can be safely flown while in a landing configuration, typically with flaps extended. Understanding this parameter is essential for pilots, as operating the aircraft below this speed with flaps extended can lead to an uncontrollable stall, particularly during critical phases of flight such as approach and landing. This benchmark is often referenced in training scenarios to ensure that pilots maintain an adequate safety margin above stall speed throughout their operations. In this context, while choice A addresses controllability with flaps extended, it does not specifically identify stall speed. Choice C mentions stall speed but lacks the context of being specifically in a landing configuration. Choice D refers to minimum airspeed for maneuvering, which encompasses broader flight operations rather than the specific threshold required to avoid a stall during approach with flaps deployed. Thus, understanding the distinction and significance of stall speeds in various configurations is key to safe flying practices.