FAA Ground School Practice Test

In a specific aircraft configuration, which color indicators the power-off stalling speed?

1. The upper limit of the yellow arc

2. The lower limit of the green arc

3. The red radial line

4. The upper limit of the red arc

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

The correct answer is the lower limit of the green arc. This lower limit represents the power-off stalling speed, which is crucial for pilots to understand for safe operation of the aircraft. The green arc on an airspeed indicator signifies the normal operating range of the aircraft. Stalling speed is the minimum speed at which the aircraft can maintain controlled flight, and in the context of the airspeed indicator, it reflects the critical point below which the aircraft may stall when not generating sufficient lift. In various aircraft, understanding where the stalling speed lies within the color coding on the airspeed indicator helps pilots recognize safe and unsafe flight regimes. The stalling speed being identified at the lower limit of the green arc indicates that any speed below this threshold can lead to a loss of control if the aircraft is in a configuration where it cannot sustain flight. The other options typically represent different flight parameters, such as the upper limit of the yellow arc, which indicates cautionary speeds, and the red radial line, which signifies the never-exceed speed, marking the maximum safe operating speed. The upper limit of the red arc usually indicates the maximum speed for structural integrity or airframe flexibility, further delineating the safe operational speeds for various flight conditions. Understanding these color indicators helps