Definition
The radar display symbols generated when an aircraft's transponder receives an interrogation signal from a ground radar and replies with a coded response containing identification and altitude information. These returns appear on the controller's scope as data blocks showing the aircraft's position, assigned squawk code, and Mode C altitude readout.
Plain English
The signals that come back from an aircraft's transponder and show up on the controller's radar screen, telling the controller who the aircraft is, where it is, and how high it is flying.
Context Anchor
Seen in air route traffic control center discussions, where controllers use aircraft transponder information to track traffic over large areas.
Derivation
Transponder is a blend of 'transmitter' and 'responder' — a device that responds by transmitting. 'Returns' comes from radar usage, where any signal that comes back to the radar antenna is called a return. Together: the replies that come back from the transponder.
Why Pilots Care
Enables precise aircraft identification and tracking so controllers can maintain safe separation in controlled airspace.
Analogy
It is like someone calling out, “Aircraft 123, where are you?” and the aircraft’s equipment automatically answers, “Here I am, and this is my information.”
Intuition Check
Returns does not mean the aircraft is returning to an airport. Here, returns means electronic replies received back by air traffic control equipment.
Example Sentence 1
The controller used transponder returns to track each aircraft's altitude and position across the sector.
Example Sentence 2
When transponder returns faded, the pilot was asked to verify altitude and position directly.