Definition
An occurrence attributable to an air traffic controller in which the applicable separation minima between aircraft, or between an aircraft and terrain or obstacles, were less than required. It is a reportable event used by the FAA to track losses of separation in controlled airspace.
Plain English
A situation where a controller allowed two aircraft, or an aircraft and the ground or an obstacle, to get closer than the rules permit. It is the controller's equivalent of a pilot deviation and must be reported and reviewed.
Context Anchor
Seen in air traffic control reports, safety reviews, and post-flight discussions after an unusual or unsafe event.
Derivation
From 'operation' (the conduct of air traffic services) and 'incident' (an event of note that falls short of an accident). The pairing signals an event during ATC operations that is serious enough to record but did not result in a collision.
Why Pilots Care
Reporting operational incidents allows the aviation community to identify risks early and improve procedures before they lead to accidents.
Intuition Check
An operational incident is not the same as an accident. It can be a serious reportable event even when no one is hurt and no aircraft is damaged.
Example Sentence 1
The controller filed an operational incident report after radar showed the two aircraft passed within 2 miles of each other at the same altitude.
Example Sentence 2
Reviewing operational incidents from the past month helped the operator update its taxi procedures.