During which scenario is a departure strip considered to be no longer needed?

The correct choice is based on the principle that a departure strip is primarily used for managing a flight's departure from the point of origin. Once an aircraft is radar identified, air traffic controllers have confirmed its position and movement through radar technology. At this stage, the flight is considered to be under active control and monitoring, making the departure strip less essential for tracking its progress.

In the context of air traffic management, the departure strip serves as a tool for initial clearance and coordination, but once radar identification has been established, the strip's primary purpose is fulfilled. The controller can rely on radar data to monitor the aircraft's flight path, which supersedes the need for the physical strip that was originally used to track the flight's departure.

Understanding this process emphasizes the role of technology in air traffic control, where radar systems enhance situational awareness and operational efficiency, allowing controllers to effectively manage flights after they have been identified.