Doug Cameron: I've seen a couple of times a pilot come back through, through the cabin to make people a little bit wary. What are they, what are they looking at?
Geoff Murray: Well, usually when I'm going back there, because the fluid is strong, I will tell the passengers, Hey, that fluid's really strong. I'm just back here to make sure the wing is still attached. You know, so I'm back there like checking some bolts. I'm obviously kidding.

Narrator: Welcome to the KnowEntry podcast presented by no delay.

Doug Cameron: Fine. Welcome to the KnowEntry Podcast, where we take you behind the cockpit door, hopefully to provide expertise you wouldn't find anywhere else to make your travel experience just a little bit easier. In Chicago today, it's minus 16 with the windchill.
My car sorted. I did the anti freeze at the weekend, but we know that it's going to affect all mechanical instruments, and that includes something complex like a plane. So to lead us through, we've got Noam Alon. and Geoff Murray, two experienced pilots who've also worked across the airline industry in their long careers.
Let's start. Why does it matter when it's cold for a plane? What doesn't a plane like about the cold? I know what my car doesn't like. What about planes? No.

Noam Alon: Well, I mean, basically, beyond the similar things that you talked about with your car, so engines need time to warm up and mechanical things like the hydraulics need time to warm up as well. Beyond that, the basics of cold weather operation, especially when there's any kind of precipitation, snow, ice, something like that, is the airplane has to be what we call, In other words, it needs to be clear of any adhering frozen precipitation, snow or ice. So a big part of de icing, what people are familiar with, if they've flown in the winter time is getting that airplane clean. So that's the first part is getting it on clean on the ground. And then in the air, it's making sure that the airplane stays clear of adhering ice. And there's all sorts of systems on the aircraft that help keep the airplane clean so that wind can generate lift and the airplane can perform the way it's designed.

Geoff Murray: And that that's that is the big deal. The big deal is to fly, you got to have a wing. The wing can't have any stuff on it. So when you get out to the airport in the winter and you see that it snowed, it's like we got to get the snow off the wing. And that is part of literally D icing. You could also call it D snowing.
You're you just got to get all the snow, all the contamination, you All that stuff that could destroy the ability of the aircraft to generate lift and fly, we gotta get it off the airplane. So just like Noam said, the concept we use, really simple, is clean aircraft, and it means the aircraft doesn't have any contamination, no snow, ice, freezing ice pellets or anything on it before we take off. Pretty, fairly simple.

Doug Cameron: So, Noam, I suspect many passengers have experienced a bit of ground de icing. It sounds a little like you're going through a car wash sometimes. Maybe you could, you could let us know both what you might expect when a plane's being de iced on the ground, and also, what can also feed into delays sometimes, what can, what takes time?
How long does it take? I know how long it takes to go through a car wash. How long does it take to de ice a plane?

Noam Alon: It's a function of a couple of things, but for the most part, it's really, A process of taking any snow or ice that's on the airplane and removing that and there's a specific fluid that we use. It's a kind of an amberish color. It's applied hot to the airplane and it removes anything that's On the airplane, and then if there's no current precipitation, that's where it stops. All you need is an airplane to be clean. But if it's still snowing, then we apply a second type of chemical. We call it type 4 fluid, and it's green in color.
And that's applied cold, and what that does is it stays on those moving surfaces, like the wing, the tail, and all the flying portions of the wing and tail. To make sure that nothing can stick if it's still snowing and then there's a whole process that takes about 15 to 20 minutes I would say if the de icing truck is available right away And if you're the first airplane that is in queue to get de iced so about 15 or 20 minutes pretty quick But anyway, that's the process kind of like a car wash.

Geoff Murray: I think that's a good one. How do you know when you're finished? Good, good question Doug. So, we're communicating with the folks who are doing the actual de icing, the folks who are out on the de icing truck, they're telling us where they are on the aircraft, they're telling us, hey, we finished the type one, which just like Noam talked about is basically clearing the airplane. And that's just like Noam said, it's a warm fluid. So if you're sitting in the back of an airplane, you're watching an aircraft get de iced and you see steam coming off of it. You know, that's the type one fluid and what they're doing is clearing the airplane and they'll tell you when they're done with that.
Then they'll say we are starting the type four and the type four is the fluid just like Noam talked about It has a really interesting chemical Property to it that basically melts ice and snow for a certain period of time when that ice or snow touches the fluid. So the whole idea is they're spraying this green fluid.
And in the winter you've been O'Hare, Minneapolis, Detroit, you see planes taxiing around and it looks like they have green wings. And that means that that type four fluid has been applied to it. has been applied to the wings. So the guys doing the de icing or the women doing the de icing, they're telling us what they're doing, they're telling us where they are, and the most important thing they tell us is when they started and when they stopped.
So we started applying type 4 at 15 minutes after the hour, we finished the type 4 at 25 minutes after the hour, and then to get into some complexities that we'll talk about in another podcast, that chemical property. gives us the ability to taxi around the airplane to get down to the end of the runway to ensure that ice and snow won't continue to accumulate on the airframe.
So the quick answer to your question is we're in radio communication with the team and they tell us when they're done. Noam, do you ever have to do it twice if

Noam Alon: it keeps snowing? That can happen. So just like Geoff is saying, the chemicals have properties that they can handle a certain amount of precipitation, amount of snow.
And at some point they get saturated and then their property of keeping the wing clean ends. And so we have tables or we have now with technology, we've actually got an app that takes all the information into account and tells us the fluid will last, let's say 45 minutes or an hour. If we're taxing around beyond an hour, then we either have to check that the fluid is still maintaining its, its viscosity, or if it's lost it, then we have to go back.
And that's obviously a very frustrating element if you're looking from a delay perspective, because you think you're going to get to take off and be airborne and then you have to go back and get back in queue, that can be very frustrating, but we're always going to take safety as the first priority.
And if that's what we have to do, that's what we have to do.

Doug Cameron: Geoff, every driver might have their own scrape or every plane can have its own. de icing facility. So who decides and how is it decided who gets de iced first and where your, where your place in the line is?

Geoff Murray: So that's, that's actually a bit of a dance.
And in, at most airports, for example, in the morning, if there was precipitation overnight, the, the airport, the airline will actually go to every aircraft CNA to gate. And this just happened to me the other day because there's, there's some interesting elements associated with de icing fluid. It's really slippery.
So if you're a bozo pilot outside doing your pre flight, make sure you're wearing good shoes with a good heel so that you don't slip and fall. But they will go around the airport in the morning and they will spray every single airplane. And then, and typically with type one, right, typically with type one, exactly.
Noam with the type one, all they're doing is clearing the airplane. But then it is, as I'm sure Noam can attest to, it's a bit of a dance. Like we're all trying to, Hey, get everybody on board. Let's get the before start checklist done. Let's get the motors going so we can be first in line, but there's not like a.
Like a chess master up there who's saying, Hey, flight number one, two, three, you wait for this guy. It's a very, what's the word I want to use? Very, like, equitable system. I kind of, who, who makes the first radio call? There's no first call. Right. No, they, they, they spray Noam, Noam's airplane first.

Noam Alon: The only thing I want to add though and this is important, in addition to good shoes when you're doing the walk around is you got to be careful of a drip when you're looking up at the wing and a drip of that type I gets in your eye, it really burns. Yeah. And so, yeah, good, good shoes and a pair of goggles.
Yep, exactly.

Doug Cameron: Yep. Well, let's get the image of Geoff dancing in heels out of our minds here. I think I've seen a couple of times a pilot come back through the cabin. It can make people a little bit wary. What are they looking at? So literally, what guys are you looking at? Usually

Geoff Murray: when I'm going back there, because the fluid is strong, I will tell the passengers, hey, that fluid's really strong.
I'm just back here to make sure the wing is still attached. You know, so I'm back there like checking some bolts. I'm obviously kidding. We are going back. And it's a great question, Doug, and it doesn't happen all the time, by the way. As Noam mentioned earlier, there's this thing called the holdover time.
The holdover time says, under this precipitation type for this long, you got 30 or 40 minutes. But if we're, if we're close to the boundary of that, One of us, generally the first officer, which I'm a first officer, we'll go back, we'll make a PA, hey, we're coming back to the cabin, we'll go to the exit row, we'll look out the window, and what we're looking at is to make sure we don't see any contamination, snow or ice or anything, on any of the wing, period.
And then we use the wing, we'll go look at both wings, and if the wings are clear, the assumption, and it's a very good assumption because of the way they apply the fluid, is the tail will also be clear.

Doug Cameron: And it doesn't matter if you see the fluid, if it's blue fluid or whatever color it is on the wing, that's fine, as long as it's not a foot of snow.
Geoff Murray: Well, we, in my case, I will want to see that green fluid, and I want to make sure the green fluid is still adhering to the aircraft. Oh, it's sticking there. Right, I think it's
Noam Alon: really important to know, for all the viewers of this, We're making a decision in the cockpit whether we need to come back based on a lot of information.
Just because a pilot doesn't come back doesn't mean there's a problem. And you can trust that they're, the pilots are aware of what's happening. But anyway, yeah, that's an important piece.

Doug Cameron: Yeah, keep up the process. Okay, so it's very visible what happens on the ground. What about in the air? You know, aircraft have anti icing systems.
Firstly, can passengers, if it's clear, they actually see any of that? And secondly, how do you sort of monitor it from the cockpit and know that the anti icing systems are operating? And what are they actually doing? Noam, if you want to carry on there.

Noam Alon: Sure. I mean, for the most part, once the airplane is airborne, the only place that precipitation would stick is to the leading edges of the aircraft.
So like the leading edge of the wing. the leading edge of the tail, the horizontal stabilizer, things like that. And so we've got heated surfaces. So we basically take a little bit of hot air off of the engine and we circulate that along what you'll see from the wing is like the silver part of the wing.
So that's the heated part. For the most part, we do that as a preventative. In some cases, in some aircraft, it could be a little bit different where you let it build up. And then you turn on the, the heat and you'll actually as a passenger, if you see it building up and then you see a break off, what the pilots have done is they've turned on the heat, inflated what are called boots and you'll see a crack off and disappear.
So that's actually the system working as intended. And then for the engines, you're probably not going to see that because we turn the heat on generally pretty. And we anticipate it so we don't even let it build because we don't want anything getting in the in the engine. Now, it does vary a little bit by aircraft.
Geoff, I don't know if it's different on your airplane.

Geoff Murray: No, it's similar. I mean, on the, for example, the 787 does have a slightly different program for the anti icing in the plane that Noam and I fly the Embraer 175, Noam flies the 737, both of those airplanes have have literally pipes, small pipes coming off the engine that are routed through the leading edges of the wings and they they have small holes in them and they blow hot air on the leading edge of the wings and that makes the leading edge of the wings warm So it doesn't accumulate ice, but on a handful of aircraft, like the 787, it's electric, like very much like electric baseboard heat in your house.

Doug Cameron: So there's electric, it's or the heated rear window of your plane and your car, rather.

Geoff Murray: Exactly. Exactly. So it's, it's electrically generated. heat that is heating up the leading edges of the wings, the engine cowlings, the tail and that kind of thing. So, slightly different systems.
The electric system is lighter. It doesn't rob the engine of power. So there's a whole set of advantages to it, which is why Boeing elected to use it on the 787. That's a topic for another conversation because that's a whole another conversation.

Geoff Murray: Yeah. So to finish our flight, you've landed, is there any part of the de icing process which happens between landing and you getting to the gate?

Geoff Murray: I would say there isn't, but there is an important element to that, and the element is once we land, it's the anti icing system that helped us get on the ground, it made sure that the wings and the tail and the cowlings were all clear of ice and snow and all that stuff, but once we're on the ground, and it's a day like today in Chicago where it's like 15 degrees, and you're taxiing around in slush, That slush can start to accumulate on different parts of the airplane.
And what that means is the aircraft, this, this sounds a little goofy, is accumulating weight. So I've got ice that's starting to attach to the landing gear and all that stuff. But occasionally you'll go out to the airport and you'll see them de icing and they're spraying de icing like fluid on the landing gear and stuff.
They're like, why on earth are they doing that? And the reason they're doing that, is to get rid of the ice, which has weight to it. We want the airplane to be as light as it can for takeoff. So they're going through another process to clear the entire aircraft, including the landing gear, any of these areas where slush or rain and that kind of thing could accumulate and freeze to get that, to get that off the airplane.

Noam Alon: And one other thing that I think is important to note, because passengers might notice this, if that situation happens where there's accumulated snow or slush on the ground, on our, on my aircraft, we'll actually leave the flaps down, and which is unusual for most passengers. They might think, well, oh, they forgot to bring the flaps up.
What we are afraid of is that things will get thrown up on the wing. And what the de icing people need to do is basically keep that clean for the next flight. So we'll leave the flaps down so they can get all that cleaned off for the next flight.

Doug Cameron: Okay. Well, thanks, Noam. Well, I, I take maybe five minutes every week to de ice my car.
It's obviously no surprise that every flight during the cold winter months in the North is suitably treated for everybody's safety. So, Noam, Geoff, thanks very much. We've all learned a bit today. I've certainly learned a lot from these gentlemen. So, if you'd like to learn more, don't forget to subscribe to the No Engine podcast.
And if you want extra information on flight delays and help yourself prevent them, then take a look at the KnowDelay.com website. Thanks everyone and see you next time.

Narrator: Thanks for joining the KnowEntry Podcast. For more information, visit KnowDelay.com.