Question id 815 - Communication - PPL(H) - Private Pilot License

Messages concerning the safety of an aircraft, a watercraft or some other vehicle or person in sight.
Messages concerning urgent spare parts which are needed for a continuation of flight and which need to be ordered in advance.
Information concerning the apron personell and which imply an imminent danger to landing aircraft.
Messages concerning aircraft and their passengers which face a grave and imminent threat and require immediate assistance.