Estimated Time of Arrival

Estimated Time of Arrival (ETA) is the predicted time at which an aircraft will arrive over a specific point — typically the destination airport, but also used for intermediate waypoints and reporting points. ETA is always expressed in UTC (Coordinated Universal Time) in aviation to avoid confusion across time zones.

The ETA is continuously updated during flight by the Flight Management System (FMS) based on actual groundspeed, wind data, and remaining distance. The difference between the planned ETA (from the flight plan) and the actual ETA reflects the accuracy of the forecast winds used in planning and any routing changes during the flight.

Related terms include ETD (Estimated Time of Departure), ETE (Estimated Time En Route), and ATA (Actual Time of Arrival). ATC uses ETAs to sequence arriving traffic and manage approach spacing.