Definition 1 of 2
Definition
The estimated elapsed flight time from departure point (or the current position) to the destination, based on planned groundspeed along the intended route. ETE accounts for forecast winds and is expressed in hours and minutes.
Plain English
How long the flight is expected to take from where you start to where you are going.
Context Anchor
Seen in flight planning, navigation logs, GPS flight plans, and fuel planning.
Derivation
From the French 'en route,' meaning 'on the way.' Combined with 'estimated' and 'time,' it literally describes the predicted duration spent on the way to the destination.
Why Pilots Care
Determines fuel required, arrival timing for ATC sequencing, and passenger or schedule planning.
Intuition Check
Estimated Time En Route is not the same as arrival time. It is a length of time, such as 45 minutes, not a clock time, such as 2:15 p.m.
Example Sentence 1
With a forecast tailwind, the pilot calculated an ETE of 2 hours and 15 minutes for the cross-country flight.
Example Sentence 2
ATC asked for the estimated time en route to the next fix to help with traffic sequencing.