Definition
Air traffic management measures used to regulate the rate at which aircraft enter a portion of the National Airspace System, typically by metering departures, assigning delays, or rerouting traffic to prevent demand from exceeding the capacity of an airport, sector, or route.
Plain English
When too many aircraft are headed for the same airport or airspace, ATC slows the inflow by holding some on the ground, spacing them out, or sending them a different way. Flow control is the set of tools used to do that.
Context Anchor
Seen in weather and air traffic discussions, especially when thunderstorms, low ceilings, or other hazards reduce the routes or airports that can be used safely.
Derivation
From the everyday idea of controlling the flow of something — like a valve regulating water through a pipe. ATC manages the flow of aircraft into a constrained area the same way: by limiting how many can pass through at once.
Why Pilots Care
Flow control prevents excessive airborne holding and fuel-critical delays by matching arrival demand to actual runway or airspace capacity.
Analogy
It is like metering cars onto a busy highway. The goal is not to stop traffic, but to space it so the whole system keeps moving safely.
Intuition Check
Do not read flow control as control of airflow over the wings or through an engine. In this FAA context, it means controlling the movement of aircraft traffic.
Example Sentence 1
Thunderstorms over the arrival corridor triggered flow control into the destination airport, and the crew was issued a thirty-minute ground delay.
Example Sentence 2
Pilots were advised of a ground delay program resulting from flow control measures in the arrival corridor.