What does the "green arc" on an airspeed indicator represent?

The "green arc" on an airspeed indicator represents the normal operating range for the aircraft. This range indicates the airspeeds that are safe and efficient for most flight maneuvers, including climb, cruise, and descent. Within this green arc, pilots can operate the aircraft without risking adverse aerodynamic effects, such as stalling or exceeding structural limits.

The boundaries of the green arc typically correspond to the stall speed in a landing configuration and the maximum allowable speed for safe flight. Understanding the green arc is crucial for pilots as it helps ensure that they maintain airspeeds conducive to safe and effective aircraft operation. This is foundational knowledge for managing aircraft performance throughout various phases of flight.