Yeah. That’s another goodie. Either the same number with two different companies or almost the same number with 2 different companies. If they both know each other is out there they can both be on guard. But if neither knows it until the mistake occurs, that’s a set-up to screw up. The ground and tower controllers in that vid did everything as perfectly as possible and it still happened.
That is another reason why it’s insane to me that 30 years after Tenerife we still don’t have non-blocking radios.
Stepping away from that vid specifically …
Anyone whose callsign recognizer wakes up slightly late has in effect the train of thought like “I just heard the last part of my number. Then he said do {whatever}. Quick mental replay, was that my company name on the front? I think so?. Was that the first couple digits of my callsign? I’m sure about the last two. Does the {whatever} make sense for me now?” …
Unfortunately there’s lots of room to rationalize away the discrepancy. That’s totally human nature. It’s hard work to train yourself out of that. The answer really needs to be: “I’m 100% dead-nuts certain or I’m asking for a repeat”. Nobody achieves that with 100% reliability. But the good ones always strive towards it and usually achieve it.
Returning to the vid, receiving a takeoff clearance was logically the next thing for DAL as well as for SWA. For both of them, receiving that call was fully in accordance with their expectations. But …
Beyond just the callsign, the rest of the details were wrong for DAL: wrong airline, wrong (but close) flight number, wrong runway, and almost certainly a wrong/unexpected heading after takeoff. At least one of those 4 things ought to have triggered the “This ain’t right. Timeout/Retry!” response.
One of the dangers of having that strong mental model I mentioned earlier is it can become too strong and you hear what you expect to hear, not what was really said. Another trap built into the human cognition system.
When I was in radio, sometimes I was in the newsroom preparing a newscast and dealing with a clattering teletype and storm alerts from the Weather Service radio, while the police scanner picked up calls. Somehow in all that cacophony my ears were good at picking up scanner keywords like “shot” and “stabbed”, so I could alert a reporter to go to the scene.
In the book “Serpico”, he describes his amazement that cops in a radio car with their radio playing on low volume could rise up out of a sound sleep when their unit was called, mumbling “that’s us”.
I don’t know the scientific explanation, but you can train yourself to pick out essentials from what appears to outsiders like a garble of noise.
In my old days as a police reporter for newspapers, I carried a radio and responded to any interesting calls. I became finely attuned to key words that would jump out as interesting and would ignore the rest. The obvious words like shooting, officer down, structure fire, but also supervisor, batallion chief, signal 48 (death), etc. Or anyone calling with some stress in their voice. With some fire radio, they would send a longish signal tone to alert you to the upcoming callout, usually a structure fire requiring numerous units.
It got so it seemed that my radio wasn’t even on until I heard something like that. Then I would snap to. Neat how we can do that.
A big part of being able to understand noisy radio is for everyone to use standard phrasing in a standard order. If I call the tower for clearance, I expect to hear back, “Charlie Foxtrot Alpha Tange India cleared takeoff runway 29.” Or maybe, “Charlie Foxtrot Alpha Tango India cleared taxi to Bravo, hold short of intersection” or any number of other phrases delivered in a standard way.
If instead the controller improvised and said, “Okay C-FATI, you can go ahead and start taxiing onto the runway and you can take off as soon as you want.” Or some other variation, I’d likely have to ask them to repeat because it sounds unfamiliar.
In a similar vein, a coiple of decades ago Quebec tried making pilots use French instead of English. They found that even native French speakers couldn’t understand ATC them because they were so unused to hearing radio patter in English.
I’ve told this story before, but in the semi-old days your typical big jet pilot would not wear any sort of noise protective headset. The belief was it wasn’t that noisy. Folks would wear an earbud in their outboard ear connected to the radios and leave their inboard ear free to hear the other pilot(s) talking across the cockpit.
With the result that copilots listened to ATC only and always with their right ear while Captains listened to ATC only and always with their left ear.
Of course, after some number of years as a copilot one upgrades to Captain. And has to switch ATC ears. I and many other pilots struggled with that transition for a few weeks. It just doesn’t register. Let me say that again: the exact same patter coming in your other ear just does’t register the same way.
Each seat position is also equipped with a speaker, commonly located nearly directly overhead the seat. Normally these are left off; they can be distracting to the other pilot. The “approved technique” for post-upgrade radio blindness was to turn your speaker up just enough to be barely intelligible. It was enough to push a little bit of ATC into the more familiar right ear and you’d register the calls sooner / better. After a few weeks you could wean off that crutch.
Why yes, humans really do have two semi-separate brain halves that only communicate partially.
Back in the Franch military in the 90’s, I was in a logistic section of an artillery battery? There wer 3 radios in the jeep: one for communacating with the guns and trucks of the battery (for rendez-vous of resuplly, indicating where the shells are heading and so on),
one for communicating with the others units of the division(infantry and armor positons, other artillery units firing)
and one for communications of the HQ.
each speaker had an unique identifiant, an identifiant for each battery/company and another for each division and we were very fast to pick any relevant name in the messages. The others weren’t always useless but generally that was irrelevant to us and so easy to pass in background noise.