Flight Identification (FID)
All aircraft registrations (commonly called “tail numbers”) begin with a letter followed by more letters, or a letter followed by a number. Aircraft registered in Germany have a “D” followed by a hyphen with 3 additional letters. So an aircraft registered in Germany could be “D-ABC.” “N” is the beginning letter for all aircraft registered in the United States. During verbal radio communications the complete registration is given on first contact with air traffic controllers. Usually in subsequent communications only the last three numerals or numeral and letter combinations are used.
Commercial airliners usually use the airline's name followed by the flight number. For example, “Lufthansa Flight 1291” would be listed as LH 1291 on the routing strip used by controllers while spoken as “lima - hotel - one - two - niner - one”.