An emergency situation is one in which the safety of the aircraft or of persons on board or on the ground is endangered for any reason.
An abnormal situation happens when it is no longer possible to continue the flight using normal procedures but the safety of the aircraft or persons on board or on the ground is not in danger.
Emergency or abnormal situations may develop as a result of one or more factors within or outside an aircraft, for example:
• Fire onboard;
• System failure or malfunction (engine failure, landing gear malfunction...);
• Shortage of fuel;
• Flight crew uncertain of position;
• Adverse weather;
• Pilot incapacitation;
• Aircraft damage;
An emergency or abnormal situation may result in it being impossible to continue the flight to destination as planned, resulting in one or more of the following outcomes:
• Loss of altitude;
• Diversion to a nearby aerodrome;
• Forced landing;
• Injuries or even deaths onboard.