Definition
A computerized air traffic control system used by the military that integrates en route and terminal radar data into a single display, allowing controllers to track and manage aircraft from cruise altitudes through approach and landing without switching between separate systems.
Plain English
A military air traffic control computer system that shows controllers both high-altitude traffic and traffic near the airport on the same screen, so one system handles aircraft from cruise all the way down to landing.
Context Anchor
Seen in descriptions of air traffic control equipment, facility automation, and older FAA system references, rather than as equipment a pilot operates in the cockpit.
Derivation
The name describes the system's function: 'joint' because it combines two previously separate functions, 'en route' meaning the cruise phase of flight between airports, and 'terminal' meaning the airspace and procedures around an airport where aircraft arrive and depart.
Why Pilots Care
It improves coordination between controllers so flights move smoothly from departure through cruise and arrival.
Intuition Check
“Terminal” does not mean a passenger building here. In ATC use, it means the airport-area part of air traffic control service. “En route” means the between-airports part of the flight.
Example Sentence 1
The military controller used the Joint En Route Terminal System to vector the inbound flight from cruise altitude all the way to the final approach course.
Example Sentence 2
Upgrades to the Joint En Route Terminal System allowed better handoff of flights from en route centers to local towers.