In what scenario should a pilot operate within the yellow arc?

Operating within the yellow arc of an aircraft's airspeed indicator signifies that the pilot is in a cautionary zone concerning airspeed. This range indicates that the aircraft is approaching its performance limits, and while it is not prohibited to operate in this space, it requires a heightened level of awareness and care.

When the aircraft is in the yellow arc, it is important for the pilot to be cautious due to the possible onset of situations such as stall or structural stress. This is particularly true when flying in smooth air, where the pilot can better focus on maintaining control and stability as they operate within this caution zone.

The other scenarios, such as operating in turbulent air, during takeoff and landing, or when climbing, may not provide the same environment for careful, controlled operation in the yellow arc. Turbulent conditions require the pilot’s attention to handle unexpected movements, while takeoff and landing are critical phases of flight typically managed within a different speed range for safety. Climbing also often requires higher speeds to ensure adequate control and performance, moving the pilot out of the cautionary zone. Thus, the most appropriate and safe situation to operate within the yellow arc is in smooth air and with caution to mitigate risks.