Definition
An air traffic control event in which less than the required separation exists between two or more aircraft, or between an aircraft and obstacles (vehicles, equipment, personnel) on the runway, or in which an aircraft lands or departs on a runway closed to that operation after receiving authorization from a controller.
Plain English
A mistake on the controller's side that causes aircraft to get too close to each other, too close to something on the runway, or to use a runway they shouldn't have been cleared onto.
Context Anchor
Seen in runway incursion discussions, especially when FAA material explains how runway events are grouped by who or what caused them.
Derivation
Operational comes from operation, meaning the act of working or carrying something out. Incident comes from a Latin root meaning something that happens. Together, operational incident means something that happens during operations, but in this FAA context it has the narrower meaning of an air traffic control-related runway event.
Why Pilots Care
Reporting OIs reveals patterns that can be corrected before they become accidents.
Intuition Check
Do not read operational incident as any problem that happens during flight operations. In this context, it specifically means a runway-safety event tied to air traffic control action or inaction.
Example Sentence 1
The tower's clearance for the regional jet to depart while another aircraft was still crossing the runway was later classified as an operational incident.
Example Sentence 2
Pilots review OI reports to improve awareness during busy surface operations.