The controller’s use of an aircraft call sign is also a code within a code. In some cases, the use of your call sign not only identifies you, but it also grants you special permission — or special attention.
When you are approaching a radar environment such as a Class C airspace, it is the call sign use that tells you whether or not you have been invited into the airspace… Example 1: If you call and say, ‘Louisville Approach, this is Cessna 24767‘ and the controller responds with, ‘Cessna 767, standby‘ this means that permission *has* been granted to enter the Class C airspace because the call sign was used. ‘Standby‘ means, ‘stay off the radio, but keep on coming toward the airport.’
Example 2: If the controller responds by saying, ‘Aircraft calling Louisville, standby‘ then you are *not* cleared into the airspace, because the call sign was not used. The controller is saying ‘stay out and keep quiet’ … not really what you wanted to hear.
Rule: Listen closely to the controller — the words mean more than what is actually said.
When a medical emergency takes place, the aircraft call sign is changed to ‘Lifeguard.‘ Translation: This could be an air ambulance racing a sick or injured person to a hospital. But it could also be blood donations, transplant organs, or even doctors and medical equipment en-route to an emergency. Anyone can change their call sign to ‘Lifeguard’ if they experience or respond to a medical emergency while in flight. When controllers hear ‘Lifeguard’ they will do everything possible to get you where medical attention can be reached. The controller probably will ask about the nature of the emergency so that they can have an ambulance standing by when you land.
Students are also advised to include the words ‘Student Pilot‘ as a part of their call sign on initial call up. You would say, ‘Greensboro Approach, this is Cessna 5122Bravo, Student Pilot.‘ The controllers will then provide ‘additional assistance’ while in their airspace. Some of them may even try to teach you a thing or two… You only need to say ‘student pilot’ once per controller.
BOTTOM LINE: Radio calls signs are used to distinguish aircraft one from another, so listen carefully to what the controller says and how they say it. Use your entire call sign first and abbreviate only after the controller does first. This will keep traffic separated and confusion to a minimum.
Editor’s Note: Take a minute to make sure you really understand what’s going on. As more pilots squeeze into the same frequencies, time spent with an open mike is getting more and more valuable and we could all use a little refresher to make sure we’re doing things right. If you ever get stuck on a term, or just feel like staying ahead of the game, have a look at the Pilot/Controller glossary.