General Operating Procedures — Page 66, Lesson 48

I want to walk you through how call signs work in aviation communications. This is a fundamental part of general operating procedures, and getting it right is essential for safe, efficient radio work. Let's start with aeronautical station call signs. These are the call signs used by ground stations — the towers, radars, and other facilities you'll talk to. Every aeronautical station call sign has two parts. First, there's the location name — that's the name of the airport or facility. Second, there's a suffix that tells you what unit or type of service that station provides. For example, you might hear "Brize Radar" or "Oxford Tower." "Brize" and "Oxford" are the location names. "Radar" and "Tower" are the suffixes that identify the service. Let me run through the standard suffixes so you know exactly what each one means when you hear it. An area control centre uses the suffix "CONTROL." A radar facility, in general, uses "RADAR." Approach control uses "APPROACH." If approach control is providing radar service specifically for arrivals, the suffix becomes "ARRIVAL." For departures, it's "DEPARTURES." The aerodrome control tower itself uses "TOWER." Surface movement control — that's the service that manages taxiing aircraft on the manoeuvring area — uses "GROUND." Clearance delivery, which issues your initial IFR clearance before you push back, uses "DELIVERY." Precision approach radar, which is a specific type of radar approach, uses "PRECISION." A direction finding station — a facility that can take a bearing on your transmissions to locate you — uses "HOMER." Flight information service, which provides weather and advisory information, uses "INFORMATION." Apron control or apron management service uses "APRON." Company dispatch, which is your airline's own operational control, uses "DISPATCH." And finally, a general aeronautical station that doesn't fit the other categories simply uses "RADIO." Now, here's an important practical point. Once you've established communication and it's clear who you're talking to, you can shorten things. Provided it won't cause confusion, you may omit either the location name or the call sign suffix. So "Oxford Tower" might become just "Tower" or just "Oxford," depending on the context. When you make initial contact with a station, you must use the full call sign of the station you're speaking to, followed by your own full call sign. No shortcuts on that first call. Now let's move to aircraft call signs — your own call sign. There are three types, and you need to know each one. Type A is based on the aircraft's registration marking. That's the alphanumeric code painted on the aircraft, like G-BTRY. Optionally, you can prefix that with the name of the aircraft manufacturer or the aircraft model. So you might hear "Piper G-BTRY" or "Seneca G-BTRY." The registration itself is the core identifier. Type B combines an operating agency designator — that's your airline's ICAO three-letter code, like "SPEEDBIRD" for British Airways — plus the last four characters of the aircraft's registration. So if the registration is G-ABCD, the Type B call sign would be "SPEEDBIRD ABCD." Type C uses the operating agency designator plus a flight number. This is what you'll hear most often on commercial flights — something like "Speedbird 123." Those are the three types of aircraft full call signs: Type A with the registration, Type B with the agency code and last four of the registration, and Type C with the agency code and flight number. Each one is a valid way to identify your aircraft on the radio, and you'll use whichever is appropriate for the operation you're conducting.