flightnummer

Flightnummer, or flight number in English, is the alphanumeric code used to identify a scheduled air service. It uniquely designates a specific flight on a given date and is printed on tickets, boarding passes, departure boards, and flight-tracking systems. The number helps passengers, airports, and air traffic control ensure they refer to the same service across multiple systems.

Structure: A typical flightnummer consists of an IATA airline designator (two-letter code) followed by a numeric code (one to four digits), for example AA100 or LH742. The combination identifies the particular service in timetables, reservations, and real-time updates. The same route may carry different numbers on different days or in codeshare arrangements.

Codeshare and operations: Many flights are marketed by partner airlines under codeshare agreements. The flight's public numbers may include multiple marketing identifiers, while the actual operation is identified by the operating carrier's own flightnummer. For example, a single aircraft may fly on a given leg with a single operating number, while other airlines publish alternative numbers for the same flight.

Other uses and distinctions: In air traffic management, a separate set of identifiers is used in flight plans, based on the airline's ICAO designator (three letters) plus the flight number (e.g., DLH123 for Lufthansa). The aircraft registration or tail number is a separate identifier tied to the physical aircraft, not the scheduled service. The flightnummer remains a primary commercial and scheduling reference in aviation.