Definition
A formal written document between two air traffic facilities, or between an ATC facility and another aviation entity, that defines specific procedures and responsibilities for handling traffic, sharing airspace, or coordinating operations at the boundaries where their areas of responsibility meet.
Plain English
A written agreement that spells out, in advance, exactly how two ATC facilities (or an ATC facility and another group, like a military unit) will work together — who does what, when, and where — so traffic moves smoothly between them.
Context Anchor
Seen in air traffic control and airspace coordination discussions, especially when airports, control towers, flight schools, military units, or event organizers need agreed local procedures.
Why Pilots Care
These agreements determine whether certain airspace is available, at what times, and under what conditions, directly affecting route planning and safety.
Intuition Check
Do not read this as just a friendly letter or a casual promise. In this FAA context, a letter of agreement is a formal written set of agreed procedures for how different groups will operate together.
Example Sentence 1
A letter of agreement between the approach control and the nearby military base sets the altitudes and routes used when civilian traffic transits the restricted area.
Example Sentence 2
Controllers updated the letter of agreement to allow glider operations during weekend hours.