Definition
An arc-shaped boundary, defined by a fixed distance from the airport, used by ATC's traffic flow management system to calculate when an arriving aircraft will cross the meter fix. Aircraft are sequenced and assigned crossing times based on when they are predicted to reach this arc.
Plain English
An invisible curved line in the sky, drawn at a set distance from the airport, that the controller's computer uses to figure out when each arriving plane will reach the metering point. It helps space arriving traffic so the airport doesn't get overloaded.
Context Anchor
Seen in air traffic control arrival metering and traffic-flow discussions, especially for aircraft being sequenced toward busy terminal areas.
Derivation
‘Meter’ comes from the Greek ‘metron,’ meaning ‘measure’ — here it means measuring out the flow of arrivals at a steady rate. ‘Fix’ is a defined point in space. ‘Arc’ is a curved line, in this case drawn at a constant distance from the airport. Together: a curved measuring line used to time arrivals.
Why Pilots Care
Proper use of the arc prevents bunching of arrivals and reduces the chance of holding or excessive vectoring.
Analogy
Think of it like a curved checkpoint around a destination. Once traffic crosses that checkpoint, the system starts treating each aircraft as part of the timed arrival line.
Intuition Check
Meter does not mean a cockpit instrument here; it means timing and spacing traffic. FIX does not mean repair; it means a known navigation point. ARC means the curved boundary around that point.
Example Sentence 1
The traffic flow system began calculating his arrival time the moment his aircraft crossed the meter fix arc.
Example Sentence 2
Crossing the meter fix arc too early required the pilot to slow to minimum clean speed to regain the planned sequence.