Definition
A formal written document between two air traffic control facilities, or between an ATC facility and another aviation entity, that establishes agreed procedures for handling traffic, coordinating airspace, and transferring control responsibility. LOAs supplement standard ATC procedures by addressing situations specific to the facilities involved, such as handoff points, altitudes, routing, and communication requirements.
Plain English
A written agreement between ATC facilities that spells out exactly how they will hand traffic to each other and share airspace at their boundaries.
Context Anchor
Seen in instrument flying discussions where local procedures, clearances, routes, or coordination between air traffic control facilities are being explained.
Derivation
From Latin littera (letter, written document) and Latin ad- (to) plus gratus (pleasing) — the root of agreement, meaning a mutual understanding put in writing. The term simply means a written, signed understanding between parties.
Why Pilots Care
Pilots must follow these agreements to ensure safe and legal operations in areas with unique requirements, such as military operations areas or high-traffic zones.
Intuition Check
Do not read “letter” as a casual note or message. In this context, a Letter of Agreement is an official procedure document that participating aviation organizations are expected to follow.
Example Sentence 1
The handoff altitude between the approach control and the en route center is set by a Letter of Agreement between the two facilities.
Example Sentence 2
ATC referred to the LOA when coordinating the approach for the corporate jet.