3. EMERGENCY PHASES
3.1. Definition
Emergency phases are defined in Annex 12 to the Chicago Convention:
- Uncertainty phase (INCERFA) : a situation wherein uncertainty exists as to the
safety of an aircraft and its occupants.
- Alert phase (ALERFA) : a situation wherein apprehension exists as to the safety
of an aircraft and its occupants.
- Distress phase (DETRESFA) : a situation wherein there is a reasonable certainty
that an aircraft and its occupants are threatened by grave and imminent danger
and require immediate assistance