Which category does DELTA 123 belong to?

• A. General aviation registration
• B. Airline/air carrier flight number
• C. Military callsign
• D. Weather advisory code

Answer: (B)

The main idea here is how flight identifiers are used to distinguish a specific service. DELTA 123 is the designation of a particular flight operated by Delta Air Lines, combining the airline’s callsign (Delta) with a numeric flight number (123). This identifies a single scheduled service rather than the aircraft itself or any weather or military codes.

It’s different from a general aviation registration, which would be the aircraft’s tail number (like N123AB) used to identify the airplane itself, not the flight it’s operating. It’s not a military callsign, which would be assigned to military units or missions and not use a commercial airline’s brand in this format. And it isn’t a weather advisory code, which conveys weather information rather than identifying a flight.