PIREP (Pilot Report)

PIREPs supplement forecast and remotely sensed weather with direct observation from the cockpit. They are especially valuable for conditions that are hard to measure remotely — for instance the severity of turbulence or the rate of structural icing — and they help other crews, dispatchers and meteorologists build a more accurate picture of the en-route environment.

Reports are encoded in a standardized format and are classified as routine (UA) or urgent (UUA), with urgent PIREPs reserved for hazardous conditions such as severe turbulence, severe icing or volcanic ash. They are disseminated through air traffic and aeronautical information channels so the observation can reach others operating in the same area.

PIREPs sit on the safety side of operational risk rather than the security side. AeroVigil's broader purpose is to consolidate official safety and security signals affecting a route; observational reports like PIREPs illustrate the kind of first-hand, time-sensitive input that informs en-route decision-making.