If the safe outcome of the flight is in doubt, declare. However, emergencies come in two basic flavors: distress and urgency. Distress conditions require immediate action. The engine has quit, or the airplane is on fire.

In the realm of aviation and maritime safety, the minimum condition suggested for declaring an emergency is when a pilot or captain encounters a situation that causes distress or urgency, where the safety of the aircraft, vessel, or persons on board is in doubt. Specifically, the FAA and ICAO define "distress" as a condition being threatened by serious and/or imminent danger and requiring immediate assistance (Mayday), while "urgency" is a condition concerning the safety of an aircraft or other vehicle but does not require immediate assistance (Pan-Pan). A suggested "minimum" threshold is often taught as the moment a pilot realizes they can no longer guarantee a safe outcome without priority handling from Air Traffic Control. This includes, but is not limited to, low fuel states reaching "emergency fuel" levels, mechanical failures that compromise flight control, or a pilot becoming spatially disoriented. In 2026, safety culture emphasizes "declaring early" rather than waiting for a catastrophe to occur, as it unlocks immediate resources, clears surrounding traffic, and allows controllers to provide specialized vectors to the nearest suitable landing site.