Definition
A taxi clearance issued by ATC that returns an aircraft to its starting point or to a designated location without requiring a takeoff. Used primarily for engine run-ups, aircraft repositioning, or troubleshooting, the clearance defines a complete taxi route that loops back to a specified point.
Plain English
A taxi instruction from the tower that sends an aircraft on a route around the airport and back to where it started, or to another spot on the ground, without taking off.
Context Anchor
Used in ATC communication, especially when a clearance needs a clear pilot acknowledgment or readback before the aircraft proceeds under that instruction.
Derivation
The term comes from engineering, where a 'closed loop' is a path that returns to its starting point. Applied to taxi clearances, it describes a route that ends where it began rather than ending at a runway for departure.
Why Pilots Care
Knowing this is a ground-only clearance prevents a pilot from mistakenly lining up for takeoff. It also signals that the controller expects the aircraft to remain on the airport surface.
Intuition Check
Closed loop does not mean flying in a circle or that the clearance is no longer available. It means the communication cycle is completed by the pilot’s response.
Example Sentence 1
Ground gave us a closed loop clearance so we could taxi out, perform our run-up, and return to parking.
Example Sentence 2
In CPDLC, the system treats the message as a closed loop clearance once the pilot sends the WILCO response.