Definition
To be stable or fixed on a route, course, heading, track, or specific navigational reference, such that the aircraft is following it within the prescribed tolerances for that phase of flight.
Plain English
You are 'established' when your aircraft is locked onto a specific path or course you were told to fly, and you are holding it steadily within the allowed limits.
Context Anchor
Often heard in air traffic control instructions and pilot reports, especially during instrument approaches, route changes, altitude assignments, and course tracking.
Derivation
From Latin 'stabilire,' meaning to make firm or steady. In aviation use, it carries that same sense — not just 'on' the course, but settled and steady on it.
Why Pilots Care
Confirms the aircraft is safely on the intended course, authorizing descent, speed changes, or other actions per the procedure.
Intuition Check
Do not read established as simply “started” or “planned.” In aviation, established means the aircraft is actually settled on the assigned path, heading, altitude, or course.
Example Sentence 1
The pilot reported 'established on the localizer' after the aircraft settled onto the inbound course.
Example Sentence 2
The aircraft is established in the holding pattern and awaiting further clearance.