Because many airline incidents occur when pilots and crewmembers misunderstand one another. Consistent phraseology, especially for particularly critical communications at critical times like takeoff and landing or when resolving a problem can save time by making sure crew members understand each other perfectly.
Why do airlines and training professionals insist on a “sterile cockpit?”
This has a similar reason. The fewer things a crewmember needs to pay attention to during critical stages of flight, the more likely they are to see and respond to things that are most important.
Captain David Santo and private pilot Paula Williams discuss this below.
Paula Williams: Can we do some examples of consistent phraseology? Different ways that maybe two instructors do things that have caused problems or something like that?
David Santo: Well, there is a lot. Communication, especially the English language, there’s so much ambiguity in the English language that it’s very easy to have misunderstandings or misinterpretations. If you think about all the different dialects within the United States, and then you think of all the different dialects amongst English speaking countries.
And then you think, some of our students may be foreign students where this is not their primary language. It is so easy to have ambiguity and how do we avoid that? So, in the airlines what we’ve done is during critical phases of flight, we are very scripted. And we are scripted so that if there’s any communication that’s made that’s not part of our script, it should send a red flag of warning.
Why is this communication not what I was expecting? How does it impact the proper conduct of the flight?
Paula Williams: Yeah.
David Santo: There’s some urban legends, if you will, of things like two-crew airplanes rolling down the runway. First officer is having a really tough day. Captain looks over at him and says, cheer up. And the first officer heard gear up, and reached over and pulled the gear handle up before the aircraft was fully in the air.
Paula Williams: That’s awful.
David Santo: There’s the story about airplanes being on final approach. And in the three-crew airplanes, now pretty much bygone airplanes, but in those airplanes the engineer would set the thrust levers. And the captain says take off thrust, so the engineer took the thrust to idle. What the captain wanted was full takeoff rated thrust, he wanted full power.
So he wanted just the opposite of the response that the engineer gave him. That’s ambiguity, right? We can’t have that. Ambiguity in an airplane and miscommunications in an airplane can lead to really bad outcomes. So in the airline industry we talk about a term called threat in air management.
And in the threat in air management model we look at different defenses to prevent errors, trap errors before they put us into an undesirable state. And one of those defenses that we can put in place is standardized phraseology, especially for critical phases of flight. Like, for example, at your flight school, well if you’re flying a complex single engine or twin engine airplane.
Is it gear up, is it wheels up? What is the exact terminology that we’re going to use so that they cannot be misunderstood? Is it flaps to 3, flaps to 5, flaps to 15, or is it flaps to 1 or flaps to 0? Just whatever that call-out is going to be, is it consistent, right?
And there’s 100 ways to do something, there’s 100 different ways to accomplish this. The big picture is, it doesn’t matter what you say as long as it’s consistently reinforced across everybody who’s in your airplanes that this is the meaning of when I say this.
Paula Williams: Right.
David Santo: I’ll give you another example of consistent phraseology that has always resonated to me.
And I might misquote some of the facts but the overall story will be correct. Many years ago there was a 737 operating out of what’s now Reagan National Airport. And for an airline called Air Florida, and I believe the call sign for that airplane was Palm 90. During the takeoff role, the first officer made several, my memory serves, it was like five, different non-standard call outs.
What he was trying to tell the captain, we believe, in the postmortem hindsight, is that the engines didn’t look right to him. The engine thrust settings, the gauges which is what we use on that airplane to set thrust, was indicating that the power setting they needed, but none of the other gauges were supporting that.
All the other gauges were showing way low on power. And in fact he was right, the engines were not making enough power, the aircraft did get into the air, but then stalled. And crashed into the Hudson River that was iced over. And there’s still pictures of the helicopters pulling the passengers and the flight attendants out of the submerged wreckage of that airplane.
Had that captain fully embraced and understood the philosophy behind a sterile cockpit. What is sterile cockpit? Any non-scripted phraseology during a critical phase of flight should raise a red flag of warning. Now, it’s easy to Monday morning quarterback. Okay, so I’m not in any way trying to pick on these guys. But, from a learning lesson, what they can teach us, is that had the captain said I don’t understand why you’re making these non-standard call outs, so I’m going to abort the take off.
What they would’ve discovered, had they gone back to the gate, is that their engine probes were iced up. And because they were iced up, they weren’t reading accurately. Now, that’s what we call an error chain, but consistently, if you look at the cause of most aircraft accidents and incidences, at some point, they’re related back to human factors.
David Santo: And that’s a very nice way, in most cases, to say human interaction. If there’s two of us in the airplane, a flight instructor and a student, You’ve got two people that have different visions of the situational awareness, different levels of awareness. And both of them should be working together as a team to make sure that we keep the aircraft and its occupants safe.
Great. So consistent phraseology is really, really important to that.
Paula Williams: So it sounds like having two, the whole purpose of having two pilots assumes that you’re communicating well. When you’re not communicating well, if you’re not using consistent phraseology, then having a crew there almost impedes the safety of the flight, rather than adds to it.
Because of that communication factor, that possibility of things getting in the way of what somebody already knows is not a good situation or already knows isn’t the way things should be and impacts their decision making in a bad way rather than in a good way.
David Santo: Well and that’s absolutely right.
So you look at years ago, Northwest Airlines also a bygone airline that’s now part of Delta. They lost an aircraft in Detroit, and during the taxi out they were really distracted by an aircraft that had landed with the call sign of water ski. And they were talking about water skiing, the commute, that had nothing to do with their flight, right?
So, what is sterile cockpit? No extraneous conversation during critical stages of flight except those duties required for the safe operation of the flight. So the focus has to be on proper conduct of the flight. Now, in a flight instructor situation, we can’t say hey the flight instructor can’t be talking to the student during the taxi out and during critical phases of the flight, but the conversation needs to be pertinent.
Paula Williams: Mm-hm.
David Santo: And clear, unambiguous, using advocacy statements and inquiry questions to make sure that there’s a good feedback loop, that we’re hearing what was intended to be transmitted, and we’re repeating that back to make sure that we got it right.
Paula Williams: Mm-hm.
David Santo: So that we have a very precise, even though it’s flight instruction and we’re talking during critical phases of flight, it’s still very precise. We’re not talking about cars and girls and airplanes and boats and any of the other many things that can distract us. We have to stay focused on what’s at hand.
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