Definition
The spacing in time, expressed in minutes and seconds, that air traffic control plans between successive aircraft arriving at the same airport. It is calculated to meet the airport's required arrival rate while maintaining safe separation on final approach.
Plain English
The gap ATC sets between one landing aircraft and the next, so traffic flows steadily and stays safely apart.
Context Anchor
You may see AAI in FAA abbreviation lists, traffic-flow discussions, or air traffic control planning material related to managing arrivals.
Derivation
Interval comes from an older word meaning a space between two things. In aviation, that same idea becomes the spacing between one arriving aircraft and the next.
Why Pilots Care
When ATC tells you to slow down, extend a leg, or take a vector on arrival, AAI is often the reason. Knowing this helps you anticipate flow control instructions during busy arrivals rather than being surprised by them.
Intuition Check
Do not read interval here as just a casual gap. In this context, it means planned arrival spacing used to manage aircraft flow.
Example Sentence 1
Approach control increased the AAI to two minutes after the runway was briefly closed for an inspection.
Example Sentence 2
Changing the AAI from two miles to three miles reduced the arrival rate during low ceilings.