When is the coordinated airspace use cancelled?

The correct answer highlights that the cancellation of coordinated airspace use occurs when it is deemed no longer necessary. This is fundamental in air traffic management, as coordinated airspace use is typically established to ensure safety and efficiency among multiple aircraft operating in a particular area. When the circumstances that initially required coordination change—such as a reduction in traffic, a change in flight paths, or improved weather conditions—the need for that coordinated use diminishes.

Effective airspace management requires continual assessment of the operational demands. If the air traffic control determines that the conditions have stabilized or improved, and that aircraft can operate safely without coordination, then the use is cancelled. This approach allows for a dynamic response to changing airspace conditions, promoting both safety and operational efficiency.

The other options provided suggest scenarios that do not necessarily align with the principles of coordinated airspace use. For instance, a shift change in air traffic control or a particular time of day does not inherently represent a cessation of the need for coordination; similarly, requiring that all aircraft have landed before cancelling coordination may not reflect the fluid nature of air traffic management, where real-time conditions are constantly changing.