Definition
A Monitor Alert Parameter is a numerical threshold used by Air Traffic Control's Traffic Flow Management system. When the predicted traffic demand for a specific airport, sector, or fix exceeds this preset value over a given time period, the system generates a Monitor Alert, signaling that traffic flow management action may be needed to prevent overload.
Plain English
It's a set number that tells controllers when an airport, airspace sector, or fix is about to get too busy. If predicted traffic goes over the number, the system raises a flag so controllers can take action.
Context Anchor
Seen in FAA traffic flow management, especially when busy airports or airspace areas are being watched for too much demand.
Derivation
Monitor' means to watch over time; 'Alert' is a warning; 'Parameter' is a set value or limit. Together: a watch-value that triggers a warning when crossed.
Why Pilots Care
When a MAP is exceeded, pilots may experience ground stops, ground delays, reroutes, or expect-further-clearance times. Knowing this helps explain why delays happen even in good weather — the system is protecting capacity at a downstream airport, sector, or fix.
Intuition Check
MAP here does not mean a navigation chart, and it does not mean missed approach point. In this context, MAP means a traffic-management trigger value used to watch demand.
Example Sentence 1
Traffic flow specialists initiated a Ground Delay Program after predicted arrivals exceeded the airport's Monitor Alert Parameter.
Example Sentence 2
Traffic managers reviewed the MAP values before deciding whether to implement a ground delay program.