Certified Flight Instructor - Flight Instructor Airplane Practice Exam

What is the minimum controllable airspeed with flaps extended indicated by on an airspeed indicator?

1. The upper limit of the white arc

2. The lower limit of the white arc

3. The red radial line

4. The yellow arc

The correct answer is: The lower limit of the white arc

The minimum controllable airspeed with flaps extended is indicated by the lower limit of the white arc on an airspeed indicator. This lower limit represents the stall speed in a specified configuration, which includes the flaps extended. Understanding this concept is essential for pilots because operating below this speed while the flaps are deployed can lead to a stall. The white arc itself indicates the speed range for safe flap operations, and knowing where minimum controllable airspeed falls helps pilots maintain appropriate control of the aircraft during maneuvers that involve flaps, such as landing or a go-around. This makes the lower limit of the white arc a critical reference point for ensuring safety and proper aircraft handling. The other arcs on the airspeed indicator serve different purposes; for instance, the upper limit of the white arc relates to maximum flap extended speed, while the red radial line indicates the never-exceed speed, emphasizing the importance of understanding different speed values for safe flying.