Miles-in-Trail
An ATC spacing requirement that mandates minimum distance between aircraft traveling to the same destination or through the same airspace.
What is MIT?
Miles-in-Trail (MIT) is a traffic management technique where air traffic control requires a minimum distance (in nautical miles) between aircraft heading to the same destination or passing through the same airspace fix. For example, '20 MIT to JFK' means aircraft must be at least 20 nautical miles apart when heading to JFK. MIT restrictions reduce arrival rates and can cause departure delays as controllers work to achieve proper spacing.
Common Causes
- Weather reducing airport capacity
- En route congestion
- Runway configuration changes
- Sector capacity limitations
- Flow control requirements
Impact & Duration
Impact Level
Low to Medium - Creates spacing delays, typically adding 10-30 minutes to flight times
Typical Duration
1-4 hours depending on underlying conditions
Frequently Asked Questions
How does MIT affect my flight?
Your departure may be delayed until proper spacing can be achieved with aircraft ahead of you. Once airborne, you may fly at reduced speed or take a longer route to maintain required separation.
Why are MIT restrictions used instead of a GDP?
MIT is a lighter touch than a GDP. It's used when some traffic management is needed but a full ground delay program would be excessive. MIT allows more flexibility while still managing flow.
Related Terms
Ground Delay Program
An FAA traffic management program that assigns specific departure times to flights heading to a congested airport.
Volume Delays
Delays caused by air traffic demand exceeding the airport's or airspace's capacity to handle flights.
Airspace Flow Program
An FAA program that manages traffic through specific areas of airspace affected by weather or congestion.
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See if any airports currently have this type of delay active.
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