Definition
A radar display tool used by air traffic controllers at airports with converging runways (runways whose centerlines, if extended, would intersect). The CRDA overlays a 'ghost' image of an aircraft approaching one runway onto the controller's view of the other runway, allowing the controller to sequence and space arrivals to both runways as if they were a single runway, ensuring safe separation at the convergence point.
Plain English
A controller's radar tool that helps land planes safely on two runways whose paths cross. It shows a fake duplicate of each plane on the other runway's approach line, so the controller can space everyone out and prevent two aircraft from arriving at the crossing point at the same time.
Context Anchor
Seen in airport operations, approach control, and acronym lists for procedures involving converging or intersecting runway operations.
Derivation
Converging means 'coming together at a point' (from Latin convergere, 'to incline together'). The runways converge because their extended centerlines meet. Display aid simply means a visual tool added to the radar display to help the controller make decisions.
Why Pilots Care
It supports safe and efficient simultaneous landings by helping controllers maintain proper aircraft separation.
Intuition Check
Do not read “display aid” as a cockpit display for the pilot. CRDA is mainly an air traffic control tool used by controllers to help manage traffic spacing.
Example Sentence 1
With CRDA active, the controller slowed the inbound Cessna by ten knots to maintain spacing against an arrival on the converging runway.
Example Sentence 2
Pilots on converging approaches benefit from the controller’s use of CRDA for precise timing.