Listening to ATC: What’s Said Over the Radio?

Many people know what air traffic control (ATC) is. However, what many people don’t know is what is actually said over the waves. Sure, expressions like “cleared for takeoff” and “you’re cleared to land” are synonymous with flying, and perhaps even casual conversation, but there’s an extensive amount that goes on as a commercial flight makes its way between point A and point B. And while recounting the transmissions of an entire flight would likely be too extensive for both my brain and your attention span, I’m here to provide insight into what actually happens over the radio.

Air traffic control transmissions are very much based in formula and logic. The controller gives the pilot(s) directions, and the pilot(s) repeat them back to the controller verbatim to make sure they’re understood. Moreover, the global “language” of aviation is English, so you can go around the world and hear pilots and controllers speaking the same tongue. Indeed, the fact that dialogue over ATC radios is very predictable is part of what makes such communications work so well.

However, for all of the consistency that occurs within ATC, there are some interesting iterations and idiosyncrasies that occur over the waves. For example, British pilots have a tendency to use the word “decimal” instead of “point” when giving or receiving frequencies. Furthermore, while the general tendency of ATC is to use single digits when saying flight numbers (e.g. “American one-two-three instead of American one twenty-three”), some pilots and controllers will use the latter. With all of this in mind, I’ll do my best to use the completely original language* (e.g. differentiating between “flight 1-2-3” and “flight 1-23”) in recounting this particular flight, and you can both listen to and read the condensed transcript further down this page.

British Airways 214 — “Speedbird 80 Golf heavy”

If you’ve read the homepage of this site, you’ll know that all British Airways flights are called “Speedbird” by air traffic control. What’s more interesting, though, is that not every airline flight uses its actual flight number – that is, the number that you see on your ticket – in its communications with air traffic control. Instead, some airlines assign certain flights an alphanumeric identifier for air traffic control transmissions, which end with the word “heavy” in the case that the aircraft has a maximum takeoff weight of more than 300,000 lbs. In British Airways’ case, instead of a given flight being called “Speedbird + [flightnumber]” by air traffic control, sometimes it is actually referred to as “Speedbird + [number] + [letter of phonetic alphabet] + [^heavy#].”

Why do airlines do this? There are myriad reasons, but it all boils down to this: the desire to reduce the potential for confusion. For example, think of how the number 113 sounds when said aloud. Sure, it seems pretty easy to pronounce on its own, but then consider how much 113 could be mistaken for 114, 115, 116, 117, 118, or even 119. By assigning the majority of those flights unique alphanumeric identifiers, the airline is able to reduce the chance of a given flight number being misheard.

As you can see in the list below, less than half of British Airways’ flights between Boston and London have the normal flight number (such cases are in bold) as part of its ATC identifier:

  • 202 (to LHR) — Speedbird 51 Bravo heavy
  • 212 (to LHR) — Speedbird 45 Bravo heavy @
  • 214 (to LHR) — Speedbird 80 Golf heavy
  • 238 (to LHR) — Speedbird 29 Golf heavy
  • 203 (from LHR) — Speedbird 50 Golf heavy
  • 213 (from LHR) — Speedbird 213 heavy @
  • 215 (from LHR) — Speedbird 21 Golf heavy
  • 239 (from LHR) — Speedbird 239 heavy

Enough With the Background…Time to Listen!

Clearance Delivery

Before an aircraft can even leave its gate, it must call the clearance delivery frequency. Essentially, this is the preliminary point where pilots do all of the “basics” before flying the route: confirming the departure route or SID, receiving a squawk code for their transponder, and – ultimately – verifying that they’re cleared to fly to their destination.

As such, the pilot manning the radios for this particular night’s edition of Speedbird 80 Golf heavy makes the initial call to Boston Clearance. In this call, he tells the controller his flight’s callsign, aircraft type, where he’s flying to, and what “information” he has, which details things like weather conditions, which runway is in use, and altimeter settings.

“Boston Clearance, good evening, Speedbird 80 Golf heavy, 747, we have information Hotel, looking for clearance to London Heathrow, please.”
“Speedbird 80 Golf heavy, Boston Clearance Delivery. Cleared to Heathrow Airport via the CELTK4 departure, then as filed. Climb via the SID, squawk 3473.”
“Squawk is 3473, the rest copied, thank you, Speedbird 80 Golf heavy. Confirm [Runway] 3-3 Left for us today?”
“Speedbird 80 Golf heavy, that’s correct. If you would just verify CELTK4 departure and as filed, then you can contact ground on point niner for the push.”
“I have indeed confirmed the CELTK4 with the flight plan, climb, and ground for the push, thank you, Speedbird 80 Golf heavy, bye bye.”

Ground Control

While the ground controller has myriad responsibilities, they’re mainly tasked with ensuring the flow of traffic in and around the gates and ramps (parking areas). Even if an aircraft is still on the ground, it’s usually the tower controller who’s responsible for planes when they’re crossing runways or getting close to their departure point. Nevertheless, Speedbird 80 Golf heavy’s next step is to contact the ground controller in order to start the “pushback” from the gate, and subsequently the start of the engines.

“Ground, hello, it’s Speedbird 80 Golf, we’re on Echo 4, requesting push and start.”
“Speedbird 80 Golf heavy, Boston Ground, give way to Swiss Air off to your right side, they’re going back. After they’re out of there, you can go ahead and push back.”
“Giving way to Swiss Air, once he’s out of the way, push is approved on Echo 4, Speedbird 80 Golf heavy, thanks.”
“Speedbird 8-0 Golf heavy, if you want to push back and push your tail to the south, nose towards Alpha 1, towards Zulu, you can do that.”
“Tail south, nose towards Zulu, understood, Speedbird 80 Golf heavy.”

After the aircraft has been pushed back, the engines have been started, and the adjacent aircraft has vacated its position, it’s time for Speedbird 80 Golf heavy to start its taxi.

“Ground, it’s Speedbird 80 Golf heavy, we’re right in front of the Swiss Air, and we’re requesting taxi as well.”
“Speedbird 8-0 Golf heavy, behind Swiss Air, Runway 3-3 Left, taxi via Zulu, Bravo, Charlie. Cross Runway 4 Left, hold short of Runway 4 Right.”
“By the Swiss Air, taxi right on Zulu, Bravo, Charlie, cross 4 Left, hold 4 Right, Speedbird 80 Golf heavy.”

At a certain point – usually when the aircraft is about to cross a runway, the ground controller will hand the aircraft over to the tower frequency. As such, Speedbird 80 Golf heavy is told to change its frequency.

“Speedbird 8-0 Golf heavy, monitor tower 128.8.”
“128.8, Speedbird 8-0 Golf heavy.”

Tower and Takeoff

After the aircraft in front of it departs, Speedbird 80 Golf heavy is told to line up and wait on Runway 33 Left.

“Speedbird 80 Golf heavy, Runway 3-3 Left, line up and wait. Caution wake turbulence from the heavy A330 Airbus.”
“3-3 Left, line up and wait, Speedbird 8-0 Golf heavy.”

Once the departing aircraft is no longer in Boston Tower’s airspace, it’s time for Speedbird 80 Golf heavy to take off.

“Speedbird 80 Golf heavy, Runway 3-3 Left, cleared for takeoff.”
“3-3 Left, cleared for takeoff, Speedbird 80 Golf heavy.”

The plane hurtles down the runway, picking up speed until it has hit its rotation speed. At that point, the pilot raises the nose off the ground, and the aircraft is airborne. Shortly after the plane leaves the ground, at around the point where the landing gear has been retracted, Boston Tower will hand off the aircraft to the departure frequency.

“Speedbird 80 Golf heavy, contact Boston Departure.”
“Boston Departure, Speedbird 80 Golf heavy, bye.”

The Departure Controller

The departure frequency is mainly to provide aircraft with initial vectors (below 10,000 feet) once they’ve left the airport. This frequency usually doubles as an approach frequency for arriving aircraft below 10,000 feet, but the frequency has two different names – departure for outbound aircraft, and approach for inbound aircraft.

“Departure, hello, Speedbird 80 Golf heavy with you, passing 2 thousand climbing 5 thousand on the CELTK departure.”
“Speedbird 8-0 Golf heavy, Boston Departure, radar contact, climb and maintain 1-4 thousand.”
“Climb and maintain 1-4 thousand, Speedbird 80 Golf heavy.”

When Speedbird 80 Golf heavy’s altitude is about to hit 10,000 feet, the departure controller will hand the flight over to Boston Center, which controls all flights above 10,000 feet within the New England airspace.

“Speedbird 8-0 Golf heavy, contact Boston Center, 128.2.”
“128.2, Speedbird 80 Golf heavy.”

Center Controller

As Speedbird 80 Golf heavy continues its journey, it will be in touch with a number of different ARTCC “centers.” After it leaves United States airspace and crosses into Canadian airspace, it will call Moncton Center. After that, Gander Oceanic Control, which covers half of the North Atlantic. For the other half of the North Atlantic, it will go to Shanwick Oceanic Control, which is a portmanteau of Shannon, Ireland, and Prestwick, Scotland. Finally, it will call London Center, who will help it begin its descent into London Heathrow.

First, however, it must call Boston Center. As such, the pilot manning the radios makes the call when the aircraft is getting ready to cross above 10,000 feet.

“Boston Center, hello, Speedbird 80 Golf heavy with you, passing 9 (“niner”) thousand climbing 1-4 thousand on the CELTK departure.”
“Speedbird 80 Golf, climb and maintain flight level 2-3-0.”
“Climb and maintain flight level 2-3-0, Speedbird 80 Golf heavy. Any directs you could give us would be most appreciated.”
“Roger, I have your request.”

Pilots are cleared to various waypoints and altitudes on a progressive basis, but in this case the pilot is inquiring as to whether he can be cleared to a certain waypoint on his course a bit early. On this particular night, he’s in luck: Boston Center grants his wish.

“Speedbird 80 Golf, cleared direct RELIC.”
“Direct RELIC, Speedbird 80 Golf, thanks.”

While Speedbird 80 Golf heavy will remain within Boston Center airspace until it crosses into Canada, it is about to be handed over to a different “sector,” which requires a change in frequency. As such, the Boston Center controller will tell the pilot which frequency to go to.

“Speedbird 80 Golf, contact Boston Center, 133.45.”
“That was 133.45 for Speedbird 80 Golf?”
“Confirmed.”
“Cheerio.”

The Rest of the Flight

When Speedbird 80 Golf heavy begins its descent into London Heathrow after crossing the Atlantic, it will listen to the instructions of the London Center controllers. Then, after it descends below 10,000 feet, it will go to Heathrow Director (whose role is much like an approach frequency would be in the United States). Finally, it will contact Heathrow Tower, where it will be cleared to land at London Heathrow. After touching down, it will be handed off to Heathrow Ground, who will guide it to its gate, as well as the end of its flight.

While ATC communications are business-like and predictable for the most part, the small idiosyncrasies that occur from flight to flight are what makes them interesting. In fact, there are a number of humorous controllers out there: a former Boston controller dubbed Boston John was known for his jovial demeanor and unique turns of phrase. And while most controllers are not so notable, Boston John never sacrificed clarity or put the safety of his aircraft in question; thus, the way he did his job was accepted by most.

As formulaic as the conversations over the waves are 99% of the time, the remaining 1% is what makes ATC worth listening to. After all, hearing small talk, a joke, and even the occasional laugh make its way into an otherwise predictable conversation is entertaining even for the casual listener – or at least I think so.

! Note 1: The conversations recounted here are done so solely for informational purposes.
Note 2: While the vast majority of airliners with an MTOW of 300,000+ lbs. are referred to as “heavy,” the Airbus A380 has its own weight designation – “super.”
Note 3: When applicable.
* Note 4: Edited for conciseness when necessary.
Note 5: “Heavy” is replaced by “super” when the Airbus A380 operates the flight (it made its debut on the route on March 26, 2017).