Definition
The maximum number of aircraft that an airport can accept on final approach within a given period of time, determined by factors such as runway configuration, approach type in use, weather, aircraft mix, and required separation between arrivals.
Plain English
How many aircraft can be lined up and landed at an airport in a set amount of time, usually expressed as arrivals per hour.
Context Anchor
Seen in ILS approach discussions when comparing how different procedures affect traffic flow into an airport, especially in low weather.
Derivation
Approach comes from words meaning “to come near.” Capacity comes from a Latin word meaning “to hold or contain.” Together, the phrase means the amount of arriving approach traffic the system can handle.
Why Pilots Care
It directly affects landing delays, holding times, and whether an airport can accept more traffic during peak periods.
Grounding Statement
If weather or spacing rules allow only one aircraft at a time on final, approach capacity is lower; if procedures allow aircraft to arrive safely closer together, capacity is higher.
Intuition Check
Approach capacity does not mean the pilot’s ability to fly an approach or the airplane’s performance. It means how much approach traffic the airport and ATC system can safely handle.
Example Sentence 1
When the ceiling dropped and the tower switched from visual to ILS approaches, approach capacity fell from 60 to about 40 arrivals per hour.
Example Sentence 2
During morning rush the airport was operating at full approach capacity with arrivals spaced three miles apart.