What does the white arc indicate on an airspeed indicator?

The white arc on an airspeed indicator represents the flap operating speed limits. These speeds indicate the range within which the aircraft can safely operate with the flaps extended. The lower limit of the white arc marks the stall speed with the flaps deployed, while the upper limit indicates the maximum speed at which flaps can be safely used. This is crucial information for pilots as it helps ensure safe maneuvering during takeoff, landing, and approach phases of flight. Understanding these limits allows pilots to manage aircraft performance effectively and maintain safety during operations that require flap deployment.