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Airline Pilot Technical Theory Adam Howey Airline Pilot Technical Theory Adam Howey

TCAS

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What Is TCAS

Sam. Adam. TCAS. Yeah, traffic collision. No. Traffic alerting. Traffic alert and collision avoidance system. Yeah, that's it. Which is a type of ACAS, Airborne collision avoidance system. That's the only one really until maybe some time in the future, which we might talk about. How recently have you had a TCAS RA?

00:29

Resolution Advisory I have had one or two. Where was it? Obviously flying into Amsterdam. And it was a surprise, you not really, because we could almost see the traffic coming and it look very close to us and it wasn't actually An aggressive RA.

00:47

It was actually what was the command the command was monitor, vertical speed. So basically just to fly level, right? Destruction was to carry on flying level, where we were Yeah, so it was pretty young eventful, but we obviously went through the whole process of save the day, did it?

01:01

Yeah, this guy went underneath this about 400 feet. Wow. I could say I'm all the way it was a king. Was like a king air. Okay, but, yeah, just going down the beach. We were on approaching to AMS Amsterdam. What did the Dutch have to say about that? They weren’t very interested really.

01:15

I told him that we had a TCAS RA. Told him that it was because he could hear the guy on frequency. Let's say just like yeah, we'll put in a report , rewind then TCA. Yeah, what is it? Traffic. No. But what is it? Oh, what is that? Sorry. So well, what's it done for you?

01:35

So it's It's an avoidance system built into the aircrafts transponder. Of all aircraft with mode. Charlie, with altitude information can have TCAS, and TCAS to talk to each other. So, That they can issue instructions between aircraft. They can interrogate each other and talk to each other and provide avoiding action.

02:00

To prevent to prevent a midair collision basically? Yeah, it's a tool for preventing mid-air. Mid air collision . So like, mid air collision loss of separation. One of the biggest. Categories of aircraft accidents. Yep. I think TCAS has done a good job of Definitely keep an accident rates in that category way down. Yeah.

02:23

So I think TCAS was made mandatory in about 2000s. I think in European airspace and apart from the one accident which we're going to talk about, what could that be? So, that would be the mid air collision over the German Swiss border Uberlingen, okay? Part from that one. I can't really think of any other.

02:45

Mid-air collisions. Between between aircraft that have been equipped with TCAS. Yeah. Okay. So surprises me that it was only mandated after the 2000s. Yeah, I think it was 2000. It was mandated. Yeah, pretty successful system. You like it? Yeah, yeah, I do. Yeah, I love it. It's pretty simple.

03:07

Yeah, and it's only there as a backup. If a mistake by pilot or air traffic control, Yeah it's labelled as a safety net. So yeah GPWS Ground Proximately warning system being another one TCAS. A safety, net being almost as if all other Possibilities to catch that accident have failed.

03:27

And this is the last thing that's going to Save you apart from the pilot being the The inbuilt traffic collision avoidance system if you like. We can always prevent an accident but TCAS is a safety net. There, You've told me it's to stop as hitting another aircraft from what airborne?

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03:42

What does TCAS do

Yeah. So practically What does it look like to you when you had your TCAS? So it built up our situational awareness as well, even without issuing warnings or advisories because it displays other aircraft on our navigation display. In form of a little diamond. So you can look at your map.

04:00

See other aircraft that are that are equipped with TCAS. And you can see where they are in relationship to you and what altitude above or below. So, what use is that and Well, it's good for your own awareness. Particularly in like a busy TMA around an airfield, you can Building up your situation awareness as to where you might be in the sequence for approach, where are the traffic is?

04:25

If you're maybe requesting further climber a traffic aren't giving it to you, you can maybe see the reason why because there's traffic above you, that's about to cross. So front of you, So actively we're actually using it most of the time. Yeah. For not what it was designed for.

04:40

Yeah. Exactly. I mean it is designed to raise your SA but you're looking okay. The person in fronts two and a half miles in front of me on the approach. If you get any closer that's going to be a go around close, you're saying I want to climb out this table in this but I can't because somebody's I can see somebody 2000 feet above me.

04:56

That's going to cross in front of us in the next two or three minutes. So it's like on our ND moving map kind of crudely. We almost have like the air traffic control is radar. Yeah exactly. Yeah. Except that it's not as cluttered because it only gives us certain aircraft depending on how we've got it set and Yeah.

05:16

What we thinks relevant to us. Okay, so what when we get more involved in it, what happens next? Then I suppose so it goes from a hollow sort of white diamond. The next sort of phase if you like if you're getting quite close to another potential conflict or potentially intruder, The the diamond gets coloured in.

05:35

So it's now like a solid white. That diamond and that is It's essentially potentially intruder. This that see that yeah, coming quite close to us in terms of literally, or vertically or their rate, whatever rate their climbing or descending out, or your climate, go to sending out is a potential.

05:54

Conflicts make quite proximate traffic. That's right. Yeah. So that would, that definitely draws your attention to the navigation display. I find if you see one, you see, one go coloured in. What would you do then? Okay, you can see proximate traffic. Yes. So again great tool for situational awareness.

06:13

That makes you think, right? That somebody close to us approximate traffic. So I might adjust my rate of climb my rate of descent. If it's particularly excessive, I might look at the window. To see if I can see them. So again, yeah, probably share your mental model with your.

06:29

Yeah, exactly. Say, have you seen that? I've seen that look. We've got traffic there. Even ATC, sometimes might point out that there's traffic. And your traffic in your one o'clock while thousand feet above. So it's raising or you giving your opportunity to raise your SA. Maybe think ahead about what might be next.

06:49

Possibly silently review the TCAS manoeuvre. Should it happen, Okay, so what what would happen next? So the next level would be a traffic advisory at TA and in this case, the little white diamond would turn to a orange diamond and then the system the TCAS system would then call out to you.

07:10

That i'm not going to do the impression. You have to “traffic traffic”. That's really good. Thank you, sort of an American accent. Traffic traffic, that definitely gets you attention. Yeah. So that would if not already that would draw both pilots, every airline will have different operating procedures but There will be possibly, some sort of call then between the pilots as to Who is at least in control of the aircraft or Some sort of separate procedure to almost get them ready for what may come next.

07:40

Should you manoeuvre? Now based on that? No, Well, I mean every airline might be different but I think Some airlines you might be told to maybe adjust your rates, but Other airlines will say no just Really don't don't interfere. Basically, just leave or preparing and just prepare for what may or may not.

08:01

Come next, Somebody looking for the traffic. Yeah, so one generally, one pilot will start looking out for the traffic whilst the other. There is looking in on the navigation displaying and getting ready for the manoeuvre. You know, what's next? So then the final level, which if it gets to that it is resolutionary advisory.

08:19

So, resolution advisory RA. So That's when I think the diamond goes to a square. I think you're right. Red square. Right. This all being an airbus, this is all air bus. Yeah. Obviously. And then you'll get some instruction basically from TCAS and the TCAS will actually tell you What to do and as a could be a simple as Climb.

08:40

Climb this and descends. Monitor vertical speed adjust vertical speed. Increased climb. Decrease climb. Few others as well probably. But the systems are we talking to each other? So the other aircraft may or may not get an instruction Sometimes. One, aircraft can get an RA, was the other record of trying to gets a TA.

08:58

All right, all right. So, Just stop us. Hitting another aircraft? Yep. It's a safety. Net should be the last thing. Really that saves us. That's what it looks like to a pilot. I'd say it's pretty simple works really well. It's very simple system and it does work very well and we practice it a lot in the simulator Probably over practiced it really for the actual amount that we not over practice it but we do it a lot considering.

09:22

Well, yeah, how you've had one in one and 13 years. Yeah, for two maybe things might have been tea, definitely had one into pafos. Because, airspace basis. Don't talk to each other there and people are trying to use high rates of climb to reach there. Cruise level. So, If we have an RA in the Airbus and it's pretty similar and all fleet, it's just like a really simple memory item for us to do.

09:46

Yeah, remember . What the memory item is the actions. So the actions would be to disconnect the autopilot. I'm turning off the flight directors. I'm so two reasons for that on the Airbus. Of obviously because you don't you not going to be following the flight direct just anymore. You can be following the TCAS instruction but also it reverts the thrust mode to speed mode on.

10:07

Yeah, on an airbus. So autopilot off flight, directly soft. And then following the TCAS into the green band, which is The TCAS kind of takes over your VSI, your vertical speed indicator. I know have big chunk of red and a little chunk of green. And it wants you to basically aim for the green.

10:24

So whether that's climb descent or maintain, and you should manoeuvre the aircraft into the green band. Of the way I train it is. And smoothly. But promptly so it's not it's not like a It's not yanking her But how simple is that? So green. Good, red bad. Yeah, exactly.

10:44

Definitely all pilot. Yeah, should be pretty simple for a pilot degree. Keep the authorised in. Yeah, and just just do it and just following, it didn't worry about anything else. Yeah, exactly. So it's Really simple in a really good way, really effective system. Yeah, I'm really happy with it as a system.

11:04

It's not even something that I'm sort of scared of. I don't like a GPWS but TCAS any day. Yeah, definitely that makes sense. And I think Taken into another level talking about, you know, passages on board in the commercial environment. I imagine if you had a TCSRA It's not that violence and manoeuvre.

11:24

I don't think mostly Some people have mentioned seatbelt. So it's not part of manoeuvre and I don't think they really need to know. So, is there any horizontal? Thing you need to do. In terms of well, the whole system is vertically based, which is genius. Yeah, it doesn't require you to turn left or right.

11:43

And if you're in a turn in the question is, what do you do? It? Don't matter. Yeah, he's just got a resolve, it vertically This genius and smoothly and promptly just inside the green band. If you even at high altitudes especially on a fly by wire aircraft. If you kind of Blip the side stick, you're going to end up in that green band quite quickly and smoothly, really Know.

12:04

is genius and am I right in thinking, you have four seconds to react. It might be, I think it's four seconds to react to an initial RA. Yeah, which is quite a long time, really. And if We'll talk about this maybe in a minute, a reversion. You have two seconds to react.

12:22

Yeah. Yeah. That's right. So I supposed to talk about now. So, reversion would be If either one aircraft, maybe wasn't. Following the TCAS or possibly you are Your climb climb, takes you into the path. Another aircraft. The different aircraft going above. You might get a reversion which then says, descend descend.

12:42

So you might actually swap completely what you're doing. And the green band has gone from right at the top of the VSI, your climbing to write the bottom. He has to be a bit quicker on reacting to a reversion because things are I forget the, the makes us sound pretty cool.

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12:57

Why TCAS, History

If anybody got four seconds to react but, you know, being possible not to do it really. It. So, As air traffic increased, call it in the 50s. But it was very famous mid-air collision over the Grand Canyon Which is when the FAA decided that they needed something to prevent mid-air collisions, okay?

13:16

But obviously, if you were going to increase air traffic volume significantly and mid-air collisions of factor, it has to be reduced to like near zero because The physics of the situation mean that any mid-air collision is basically always going to be catastrophic. Though, you know, in America they have a lot of mixing of like general and airliner aircraft as well into all sorts of airfields, which is like less.

13:40

I'm always surprised when I go to America, you know. Yeah. But although in Amsterdam You get our light aircraft. Yeah. Scoot and underneath you. And that's exactly what our situation was. I don't, I forget the exact details but I'm pretty sure the other aircraft and it was only yes that got the got the RA but going back you know they to come up with a system that works this.

14:02

Well was taking a long time but actually they developed it quite early on First they want to like a ground based system. And it was actually called be CAS and was like a beacon based system but I mean doesn't work over the sea Does it? And also there was issues with how busy the beacons would be.

14:19

And that's a big part of this is the the data that has to be transmitted rapidly between the aircraft. And then you imagine some of these systems were designed a long time ago and it has to compute Very quickly if there's going to be an accident but the airspace is so busy.

14:33

I mean, it must be computing all the time. Yeah and initially when TCAS was implemented, there was a lot of nuisance and you could even say spurious. Triggers of the system, which is not good because empires Blend that it was annoying and maybe not to follow us. I mean, people are getting them off boats that have transponders, right?

14:54

And this kind of thing, right? Yeah. But eventually, we’ve up with this like incredibly robust. Airborne collision avoidance system which may be superceded sometime in the future. Now, ADSB is coming out but still going to use basically the same principles that we've been using for. I don't know, like 40 years, the years.

15:14

Well, we know, yes, something like that. And then i think you're a control. Reckon, it's Decrease the chance of airborne collision by like a factor of five. Out Most of saved. A lot of lives, definitely, and I think Pilots now our generation pilots definitely love the system. And it's so good that it's actually the nuances of Of it which of course problems which is because it's such high density traffic.

15:40

Situation that we're flying through. Now, the systems just needs tweak in every so slightly just to stop as it being so annoying. So the fact that it's safe isn't even in question. Yeah. So yeah, I mean, I don't know if you remember the mid-air accolision that sticks in my mind, is the cessna that hit an aircraft in the circuit in the states and then there's a picture of San Diego.

16:02

And it was as a picture of the southwest airliner. I can't remember if it was a DC9 like on inflames going down this booty have visual contact with that right with that session 172. Okay? And they think there's a lot of confirmation like oh yeah he's gone that way or whatever and it's actually underneath them.

16:21

That was like, 144 people. There was another DC9 with, like, 80 people who died in the 80s, but this is when TCAS, basically different been developed, but then it was like accelerated. And then by the end of the 80s, we had we had like the the TCAS system Almost that we know now.

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16:40

Faults

So, It's really simple for us to use works really well. Any idiot could kind of grasp it in a few, a few minutes. However, like most of these systems, if you, it's good, if you know the memory drills, I mean, you have to not good, it's mandatory. But if you just understand slightly deeper, The system that will give you a much safer use of it And I'm only talking just scratch the surface of it.

17:05

So yeah, if you just fly in the green you'll be safe. But a couple of things like the RT and how air traffic controller involved, if you just slightly understand that That's going to prevent. Potential accidents. Which ubiling in was in there was a mix of conflict. Yeah, so my understanding now, is that extra control if someone reports TCAS RA air traffic control will just sit back and not try and issue.

17:28

Yeah my experience is totally the opposite. Really? Honestly it's totally the opposite. I found the controllers really defensive, okay. So they start talking and they start saying, no, no, it's not a problem. The bottom line is once TCSRA. Activates yeah. You ignore ATC even if they're screaming at you, even if they said Ignore TCAS.

17:55

The the law aviator Air Law is that you were follow that TCAS system. So my questions you is uberlingham was 2002. Yeah. Was that in was that made law after uberlingen or was it? It was definitely the law in the procedure joining uberlingen and however, Thing about air law is depends where you are?

18:15

Yeah, well yeah yeah was was depends whether things are standardised. And the Russians had a different idea. So the RT you need to know your RT as part of the memory action, Like to the letter. And you need to be able to What makes like, Always gone about unreliable speed.

18:36

I mean, you always do what air traffic control says but this is the one Chance. You've got a snap out of however many years of listening to our traffic control and go. No. Because in some countries they will ignore you tell you to ignore tcas , something like that.

18:50

The other thing is, That in any other situation. Don't say TCAS. Which is a really bad habit that pilots have gotten here all the time. Yeah. So you said that. When you see proximate traffic, You'll start looking for them. Next minute, air traffic control to be helpful, say others crossing traffic that and they you will always hear people read back.

19:12

Yeah, we've got him on TCAS. Yeah, but the word the phrase TCAS should only be used when you in an RA manoeuvre. Yes, that's right. Yes, yes. It doesn't help. Yeah, because that changed as well. Didn't it? And so, so, yeah. So I have to sort of consciously So say just copied.

19:27

Thank you. Yeah. Yeah you can say we visual or visual or even though when you IMC, I guess because you so anything but TCAS I'm yeah, don't say the word TCAS, I guess everybody. Oh, it doesn't, but it should get everybody's like blood pressure at basically, everyone should get that startle factor.

19:47

So that's our safety. Net air traffic control, have their own safetinets. They have like short-term collision avoidance, which is a bit of a wider. A time that the radar system will predict things like their own TCAS but yeah it's a bit it's two and a half minutes in advance of an ever.

20:06

Collision collision. And now we're moving into aircraft that will fly the tcas manoeuvre for you. Yeah, we already have that. Yeah, I'm so talking as if it's the future but it's on A350 A380. Obviously it'll just fly the manoeuvre. So, We've got high performance aircraft now especially like a hear the seven, three, 737 max is just so powerful, so you've got we've now got really high rates of climb aircraft when sometimes we don't want them, especially an upper air space and in RVSM air space, so TCAS.

20:43

Doesn't know. What we're intending to do even though the FMS does know, we're going to go into an out capture mode. So TCAS, now, often tells us off It when it thinks we're going to have a collision when we know full well, we're going to level off. Yes. And say that's something that probably will be developed into future versions of airborne collision avoidance system.

21:06

Of preventions better than cure, right? So not having high rates of climb. Is the most. Is your biggest defence against having a t-cast most of the time, because I think 80% of TCAS RAs, Are. Preventative RAs. Yes. As that make sense and they're reducing ours, IE, you've got a high rate of climb towards the level off.

21:29

It's just asking you to reduce your rate of climb, reduce your rate of descent, which you said earlier early versions of TCS actually that all warning was reduce climb But people would always go the wrong way because they'd hear the word climb. Yeah. So then they changed it to adjust vertical speed adjust, right?

21:47

Which always meant reduce vertical speed but that was too ambiguous. So now we just have “level off”. Yeah. So it used to say, oh, choose a lower vertical speed, like, you doing 3,000 feet a minute. So just choose 1500, but now they've sacked it all off. And it just tells you to level up leveller because it's Because it's easier pilots understand that.

22:07

Yeah so it stops you climbing order to send him just for a minute and then Say it was a major problem for a while that the most common RA was for you to adjust vertical speed. But a significant proportion of pilots would go the wrong way. Wrong way, not into the green.

22:25

And the other thing is they'd overreact, So it's smoothly and promptly just inside the green band, but they'd go. They'd have the start of factor, I guess. Just they remember uberlingen, and they'd go for it. All stick. And then, as you've already said, then they cause a another RA with another level, because they go too hard.

22:44

Yeah. Yeah. But I thought you manual actually says, just into the green band. Yeah, that's your goal or just out of the redband in my even second. Okay. Yeah, exactly. So TCAS is so good. We're sort of creating a little issues within the system of TCS. So having some sort of understanding a belief, the surface of how it works.

23:05

And how it interacts with ATC, definitely makes it even safer system. But it but it works really well. One. One little thing that I wanted to mention earlier, which I forgot about building up our situational awareness. You know, looking at the navigation display was the accident that happened in Milan Linate.

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23:25

Linate Airport Disaster

I remember oh, like this. Yeah. So His first tragic, really, there was a private jet, which was Somewhere where it didn't think it was. It was like this foggy day. I can't remember how long ago. This was probably 20 years ago. Up by essentially. In the low phase, this private jet thought it was on a taxi labour, It was actually on the active runway.

23:49

A traffic control. Cleared Scandinavian SAS to take off. And unfortunately the SAS hit the private jet. They had a collision on the runway. Big fireball, but because of the low vision of the fog, nobody knew that the crash had happened. Even after control couldn't see from their position that a crash had happened.

24:09

And they actually, then cleared, the next aircraft to take off, which was a left answer. And the left hands refused to accept the takeoff clearance because his SA was so high that he hadn't seen the magenta of the white diamond of the SAS like get airborne. So you know he would have seen it say yeah.

24:30

Plus zero one plus zero two. So yeah. So he refused the takeoff clearance because he said that German situational NS yeah. And i think tcas is used same much like reigning up on anything. Yeah. And especially low visit. It's very useful. For the SA now in the so with ADSB, automatic dependence valence broadcast, aircraft, that can accept that information onto their ND.

24:57

They have like a They have like an enhanced, what you would say, Ticest display tells you Might be wrong about this. I think it tells you to call sign and the type okay and the altitude probably wrong about one of these but really, really enhances your SA that information is coming from the ADSB which is different to TCAS but a future generations of TCAS.

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Future

25:23

I probably going to use. ADSB. So, the problems always been since time began, which is How do you solve the problems of? CNS, communication, navigation and surveillance. So, we've already done a podcast on A communicate, we VHF and some of the limitations of that VHF is on radio. Communication is, is a really old system, but works really well and that's one of the That's one of the main defences against aircraft.

25:51

Collisions is just read backs. You know, it's just it's just talking to air traffic control and coordinating everything. Yeah, navigation. Obviously, we used to use radio beacons and now we're moving towards. And performance base navigation. So Where we are in in space and time the aircraft now, knows better.

26:13

Then the ground knows because of our GPS input. So we can not from the ground but from the aircraft, we can tell other aircraft where Where we are better than we used to be able to. So with ADSB, We can have a like, a more accurate TCAS because a GPS position, basically is so accurate and then surveillance used to be done by.

26:33

This yet primary radar. Which would like, you know, developed in World War, I would would ping back if it be a dot on a screen. Yeah. And then you've got secondary radar, which uses the transponder. So if you interrogate a transponder, it decides, whether to send back information, like, yeah, I'm here and it can have lots of information sent with it, but definitely sends back, it's it's altitude .

26:56

And that's what TCAS uses, which is transponder. But the use of adsb in the future, He's going to just mean it's like broadband for aircraft. Basically, Lots more data travelling between the aircraft other aircraft and the ground. And say all this airborne collision of avoidance systems are going to probably start to use that.

27:16

And then if you think about like drones, like if they had ADSB on, you can have a TCAS against the drone. Yeah. You know whether it was supposed to be there or not whether it's just You know, what is already? A very sort of safe system. It's probably only gonna get even safer and even better.

27:31

They did get to. So TCAS 2 is what we're talking about. TCAS is just TAs and it was some regional aircraft had that but TCAS 3 was supposed to come in at some point and had horizontal resolutions but basically you don't need them because everything can be solved vertically.

27:50

Yeah but with I think it's called ACAS x at the moment is what they're calling it. That's like the next generation of airborne Collision of avoidance system because That's the umbrella term TCAS is almost like the brand name. So, if something else can solve airborne collision avoidance, that will come under the same umbrellas, it'll be some changes in the future, but the point I'm making is ever our sa .

28:11

A situation awareness that's coming from this pretty rudimentary like, pings from transponders. He's going to be enhanced by a ADSB and It's like a, it's so many layers of cheese in front of the, actually, using the TCAS system that keeps us safe. Yeah, other things, air traffic control, you know, like, they don't know, we've got an RA, but now we have the ability maybe to download it to them and it pings the same.

28:35

We've got an RA. Yeah, and so be all sorts of changes to it, but all these things have to be You know, I think they're basically proposing to change nothing as far as the pilot is concerned because the simpler the better. Yeah. You don't mess with it. Yeah. But the algorithms that run in the in the TCAS haven't been changed since the 80s but now the computer power is so much better.

28:57

You can have much more accurate computations about closest point of approach and stuff like that. It's definitely some changes come in. But as far as we're concern hopefully I'll just be flying the green. Yeah, stupid. Simple for us. Yeah, first pilots. So I think what we're going to talk about now Is how it managed to go wrong.

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29:18

Überlingen Mid-Air Collision

Yeah. Even they taste was well in truly involved in the accident. Yeah, the sad sad story of uberlingen is sort of referred to as the uberlingen crash, but yeah, uberlingen was the town on the ground. On the Swiss German border. On Lake Constance, where the debris of the aircraft fell.

29:37

Yeah, you've maybe done a little more research than this on this to me I sort of Feel like I know this story quite well. And this obviously world documented on Natural, geographic air crash investigation. You know, this quite a lot of stuff out there on it but You want to broadly so talk about.

29:55

Yeah happened. It is well documented because it's very dramatic. And like,, there's been plenty of films. Including did you know an Arnold Schwarzenegger film? About this about this. I think I might have known that. Yeah, I didn't know that. So I need to watch it. Now it's loosely based.

30:13

On, on this. It's a 2017, but Yeah. It's no. What's it called? I've written it down. I feel like I might even seen it. Aftermath. And did Arnold Schwarzenegger play the controller think? Maybe. Yeah, I've seen it. I've got feeling I might even seen it. Well, But I need to watch it.

30:33

Yeah. So, It's well known. It's, it's Dramatic in its in that sense, it's addictive. So there's a lot of films and podcasts and That plays and whatever, all written about it. Likes. You see after learning about it again. I think probably last time I learn about it was pretty me being an airline pilot as always becoming an airline pilot.

30:58

It's really given me. It gives me that. And, But i are basically lose. Sleepover it? Yeah. And because Our routine day job, which I'd like to say take incredibly seriously still leaves you a bit disconnected from the reality of what you do in sometimes or what could go wrong.

31:21

Yeah. I don't think it changes anything about your approach to the job. But, Definitely gives it a bit more. Makes it a bit more vivid, so, Like you said, do you like first 2002? Of aircraft taking off from Moscow, to go to barcelona. With 45 children on board as well as other people.

31:43

The school trip. Wasn't I think or yes school trips Barcelona. Yes. The children had like one their place on this trip. And for their achievements. And i also they probably been picked because they had well connected parents and bear that in mind. So, they're going to Barcelona in the evening and Like sliding doors or whatever but they're they'd missed one of their connections or it been late and this was especially charted to get them there without delay.

32:12

So the air line, the Russian airline Bashkirian. Yeah there you go. And they're flying, the Tupolev Tu-154. Which is amazing Russian aircraft that they basically had to build and design in Russia during the cold war and fly around Russia. And it's actually designed to go in like rough strips, can like land on gravel and stuff even though suggest aircraft is like, super high performance, they had like a thousand of them in Russia.

32:39

So I guess the Russians loved it, really? A little try. Try jet. Try engine thing. I don't think I've ever really been in close to it any of these things and well, they were still flying until About 2010 are likely things. So, This airline no small outfit had about 33 aircraft okay, maybe like 13 of these four of them on the flight deck.

33:03

It's a training flight and flight. Yeah. So you captain left-hand seat and the chief pilot in the right hand sea, How many times in these accidents? Is it like some combinations? Like that? Some yeah, they have a flight engineer and for no reason. There's a copilot super numerary so I don't know why he's in the flight deck but There's even some.

33:23

Ambiguity about who the piloting command was. And I You know, i just throw that in there as to whether that is any kind of contribution. So maybe, yeah. As to So they're going towards Barcelona, it has to be a training flight because I say, I guess they think Barcelona is so crazy which it is and they captain has to have two supervised visits for they go.

33:42

So that's why they're chief pilots going. Okay. But there experience flying outside of Russia is like really limited like they've only done a handful of trips each I think they're chief pilots only been outside, Russian territory twice, right? Or something but he's checking out the captain to get Barcelona.

33:59

So even there experience outside , so Russia. Is slightly limited. Meanwhile, DHL 757, we've only two people, two pilots on boards, taking off from Bergamo. And to fly north over the Alps to Brussels, and then imagine that this Russian aircraft is coming, kind of southwest generally towards Barcelona from Russia.

34:20

And it's late in the evening by the time they get towards this piece of airspace, it's about 11 o'clock at night. So, At any about halfway through the Russian sector, maybe about two hours to land in. Not long. After space, the DHL would have grab one the captain of the DHL British.

34:40

Yeah. And a Canadian first officer 757. So at this point in in history, yeah, the DHL have Had. TCAS for a while and they like you said have been training it in the simulator a lot. And so they may or may not have had one in real life, but in every check, they're doing their.

35:01

Yeah. Now If the Russian airlines want to fly outside of Russia, they have to have TCAS because as you said is been mandated, yeah, about the time in the millennium but in Russia you don't have to have TCAS. So, The Russian aircraft has got TCAS. It's been fitted. However The pilots have and the Navigator, the sorry, the flight engineer have done the I want to say CBT (computer based training).

35:27

They've done the That they've ticked a box somewhere that says, they've done the learning. They've done the learning , They've never done one in the simulator because guess what? The simulator doesn't have TCAS fitted to it. And there it's their exposure to TCAS is like incredibly limited like, The amount of sectors, whether even done a flight with TCAS on board is like a hand like, very, very few.

35:51

So, That's his aircraft approach. This piece of airspace, Simsuric controllers. Below. And well, there's one actually bases. One, this is another factors that it's always, massive is always the holes of the Swiss cheese and they left the Swiss cheese. Well, so this this unit used to always have three controllers on And it became, Common.

36:19

That the controllers would take it upon themselves to for one of the three to just sleep for the entire shift. Because then as they alternate day after day, one of them's, getting a free, a free night sleep, and then on these deep night shifts, Then due to personnel limitations, there was only two in the control room, shift?

36:40

Yeah. And for, however, long that had been going on, but still, the controllers had decided that they one of them would still sleep for the entire shift. There's only one On duty. The same time maintenance returned up, they're like “yeah, we need to do some maintenance on the, on the old radar there”.

36:58

Yep. To the radar goes into this thing called backup made, I think or degraded mode. Another hole in the Swiss cheese. Okay? An integrated mode. The radar can only do seven miles of separation, rather than five and unbeknown to the controller. The STCA short-term collision avoidance visual warning, which goes off at two and a half minutes prior to collision.

37:26

Doesn't work, doesn't work. But all one that goes off 30 seconds prior to collision does work. Now, there's a little airport down there, which I've flown into called Friedrichshafen on Lake Constance, Add This controller also has to do the area control for that. So guide the aircraft in onto the ILS, basically.

37:47

Um, but no problem because it's 11 o'clock at night and Friedrichshafen doesn't have any inbound traffic. It's part from some little airbus shows up and says I’m late and needs like vectors towards Friedrichshafen. He does that. He's working two radar screens. I think it looks like two stations.

38:03

Yeah. And So, A DHL request climb 360 and the Russian aircraft is at 360. Yeah. So, The controller is trying to co-ordinate the fact that two aircraft are going to be at 360 because he delays one of them That the climb for a minute and he's trying to get into touch with Friedrichshafen tower.

38:27

To hand over this airbus. He's coming into land. But every time he tries to use the phone, it's not working. And I don't know if that's due to this maintenance or not, or the Friedrichshafen just aren't picking up, okay? So, he keeps getting distracted. And then, just at the wrong moment.

38:44

He gets quite heads down in that problem of trying to contact Friedrichshafen Yeah. And he misses the first part of this of this TCAS. Yeah. So the two aircraft to fly in towards each other and simultaneously. They. Both. Get TCAS RAs. Yeah. And the DHL. Calls “TCAS RA” and their controller.

39:09

Doesn't hear that because he's busy with the Friedrichshafen situation. Yeah. Next minute, he notices of his own accord that these two aircraft are going to collide or. Yeah. At least they're heading towards each other. So he instructs The Russian aircraft, to descend. And to fly level, three, five zero, due crossing traffic and expedite.

39:32

He doesn't say emergency or avoiding action or anything like that. Up to the Russian stars to descend. And, This is now whilst the DHL is starting their. Manoeuvre to descend send. So just to clarify that say the Russian aircraft, They were instructed to climb on TCAS. Was that right?

39:57

And they were contradicting that by following the air traffic controllers, instruction to descend it all happen at the same time and while. Basically control is distracted. These two aircraft. Get a TCAS RA. Yeah. And the DHL aircraft is told to descend. Yeah. And the Russian aircraft is told to climb.

40:16

By the TCAS system, yeah. The. Air traffic controller wheels. This chair over sees that something's going on, has missed the fact that DHLs called over the radio TCASRA And to resolve the situation. He decides to tell the Russian to descend, fly level three five zero. I mean it's 50 50, isn't it?

40:34

I think so complete 50/50. So the Russian decide even a 25/75. Because if you'd have contacted DHL, yeah, with a conflicting instruction they might have ignored him. So DHL down game involved, because They can hear the air traffic controller, trying to deconflict is what we think happened. Initially. This.

40:57

What? I'm just describing now and folds over seconds. Yeah yeah. And now, An aural alert goes off for the controlling now which he never heard, which is totally useless anyway, because it's too too late for him to really do the for the controller to provide any Useful instructions that would result in a thousand feet of separation So it's going to be a loss of separation.

41:18

Say both aircraft to descend in. And the TCAS can see that they're still on a collision course. And so it tells the DHL. To increase the rate of descent. Hm, which they do down to 2600 feet per minute. And it now tells the Russians. To increase their climb. Even they they're not climbing, they're descending.

41:43

Now, the Russians. And CVR shows that they're a little bit confused about what to do. Yeah. Yeah. There was Can I say that there is a conversation about? It is a concept imagine you've got conflict of like you got a captain Chief pilot who's the training, captain examining, kind of examining this guy Two other pilots, well, Pilot and fly engineer all in flight deck.

42:09

This is happening pretty quickly. Interestingly the co pilot this 757 was PF. He went to the toilet . And literally, as he sat back down, And the RA was beginning, right? Now. What's amazing is these aircraft are not just at the same level. Then now descending. Yeah. But, They could be descendent at any rate.

42:34

I find it. Unbelievable. They managed to collide, like, I mean, So, I could DHL chimes in and says, Something about TCAS RA, I think they say unable to guess already. But then, in the next few seconds, the controlling gives visual. Information. To the Russians. Hmm. And says that. The DHL aircraft?

43:01

Is i think one o'clock or two o'clock? On their right side, and it's wrong. Yeah, they're on the other side, decide. Yeah. But the Russians actually spotted in the end. And that's when they start to start a climb. But it's too late, basically. So the entire vertical, stabiliser of the 757, Basically goes right through the middle.

43:25

Yeah, of this Russian aircraft, with these children on board in the middle of the night. So, the Russian aircraft is sliced into like four bits, And the 757 has no fin goes on a little bit. And just getting into a spin, just goes nose. First into the ground, 70 degrees nose down.

43:49

So, Before I talk about the aftermath, you know what, what could we unpack about that? And I mean, for me, it's I like to talk about the Swiss cheese, but there is so many little things in that, they're just remove one of them. And it probably doesn't happen. Remove that airbus going into Friedrichshafen and remove the maintenance guys in the air traffic control centre.

44:11

Removed. The The guy who's sleeping the night, he sleeping removed, the Russians, sort of following ATC rather than TCAS. I just anything. Just one little thing would probably so the Russia. So it's easy to blame the Russians, right? Yeah, I don't think you can really, I mean, but the stay had they didn't really know and they weren't required by law.

44:32

Really what? What TCAS is about Now, there manuals had about three conflicting statements in them. One that said, Be ATC is basically the final say, but another, that kind of said, you would always follow TCAS. But then another that said, you should look and try and see an avoid aircraft rather than that's your last line of defence.

44:55

So it was not objective and a must that you absolutely follow TCAS, which I think answers when you questions from earlier. So, In terms of air law, you just got a total. Fuck up there. Where The Russians are. Allowed to do whatever they want in their own airspace and then they're obviously transit in other airspace And it's not been mandated or, it's not absolutely clear what the procedure has to be.

45:21

Yeah. Another nuance now in TCAS 7.1, they changed the reversal logic. And or they updated the reversal logic so you can get reversal in TCAS but it used to be that if you if you got too close, the TCAS thought that the it's too late to command a reversal but now it will up to a later.

45:42

Point realise. Oh if one's not following out, I'll switch it around. Um because the DHL could have gone into anything of climb. Yeah, it's just bizarre that, you know, you can understand slightly two aircraft hidden each other both flying level. Because with the aeroplane flights. So accurately, but the fact that they were both in a descent, I mean, I I can't even compare, I it must it would be like two goalkeepers at different end of a football pitch, both kicking the ball, and it'd be like the balls hitting each other.

46:11

You know, be the amount of air and space up there is just so vast. Yeah. I mean, chance of two aircraft in each other. In, whilst in a manoeuvre, is some art doubtitude. It's just It's just incredibly bad. Look really. Yeah, it's horrifying. What will come on to? Another usually sleep over.

46:31

I also find A harrowing about it is that there are other aircraft that were flying around. Is a clear night that say they saw oh yeah saw the flame. You know saw the explosion basically. Yeah I mean that would just it's in July oh just stay with you forever.

46:47

Like seeing that you know it's like flying on a clear night excee hundreds of miles To see that. And and oh, yeah, horrible horrible. It just impossible to engineer this situation. Going back to the history of TCAS and mid air collisions and so on, it's it is amazing that they happen at all because I've said before, we're so used to live in on a 2D in a 2D world.

47:12

It's kind of hard to imagine how much volume there is up there. Yeah. So there is a lot of space, but Aircraft tend to congregate together, you know, in the same circuit pattern in the same, airfield the same time. Up and they're kind of attracted to each other. Yeah, you know, these, these all these layers that prevent aircraft here in each other.

47:33

And have to be there because otherwise we would all be at the same place at the same time and and that that piece of airspace there, you believe in it is a very busy bit of airspace. And although it was 11 o'clock at night in July For the to be one controller on.

47:49

I don't know too much about air traffic control but That that does strike me as as As not, right? I'm always going over that bit of airspace high altitude. Yeah. So there has to be all these things, you know, just the semicircular rule about what altitude you fly. Yeah.

48:08

And you read backs. Your the radar. Then you've got your STCA short-term collision, avoid the system, you TCAS, and so many layers that in there. That should prevent this from happening. And then, just the fact that they happen to Be so close to each other. I mean the tail of their 757.

48:28

I mean you talking like Couple of meters and it would have been a near miss or something. So, That kind of tragedy. I think difficult for humans to kind of understand. You know, in terms of our aircraft safety. Accident reports of what we go on to decide. Like, you know what what's happening.

48:50

So the next thing report didn't come out until 2004 and that's where we start to draw conclusions from and In the beginning, the air traffic control. Company responsible for air traffic, control that did. Basically blame the Russians which didn't help. What happens next? As there. Final extra reports coming out is kind of unbelievable.

49:12

But without getting too graphic, let me just Tell you what happened in the days, following the accident. Imagine you've sent your children off on an aircraft. He told that there's been no survivors and you know, quite common. I think a lot of these parents didn't believe it. The Russians flew them out there like the next day or something.

49:31

And they get to the site and this beautiful countryside. And of the site of this, this crash. If you split a spread over quite a wide distance, the the tupolev aircraft And the Russian is just join in like the the search effort. One gentleman. Vitaly. Kelly of. Goes to find his wife, his daughter, and his son.

49:58

And straight away, just Thus starts looking for for them. And he finds his daughter. In the woods. Wearingthe little necklace that she wears is young tiny little daughter and later on Basically finds his wife and his son as well. So, For a human being to be able to comprehend.

50:18

Really, what has unfolded to fly to this? This piece of countryside, like far away and, and your families lying there. You know, in the, in the days after it's just, it's incomprehensible, yeah. So the edge trafficking controller is obviously Most weird. He needs mentor treatment basically for being The edge of controller, he was responsible, at that time, the one on duty.

50:47

And, The parents had turning up to the side of the crash. And, You know, totally destroyer and there's probably a lot of anger. And the father of, if those of that family vitali Kelly of wants to me with the air traffic controller and obviously that that doesn't happen and and refuses.

51:10

And then over the next few years, you know, bits of the Accident report, start to unfold and so on. Just a few months before the final extra report. Years later. Vitali of decided to return. To that same place. And hires a private detective. To find the air traffic controller.

51:32

And decides to go and confront him. Turns up to his house. Where he himself has got three children. I think the air traffic, controller. Neilson is his surname. Confronts him in his back garden. And stabs him to death in front of his own family, then he dies within minutes. In Front of his children.

51:54

Say I said, like really terrible. turn of events, it's not really related to the aviation necessarily. But then the story gets even crazier. Because, He's arrested and he goes to prison. But he only he does like a couple of years. Putin lobbies to get him out. Yeah. And he's Has this sentence reduced for diminished responsibility.

52:21

And then he gets lobbyed gets out, then he goes back to Russia. And becomes like quite a high ranking politician. Yeah, there is area and then gets like a national award like one of the highest awards for his region for his services in politics. And, This is all sort of explains why you can see him be an interviewed on multiple locations in high definition.

52:46

Talking with complete victory, all about that controller like talking. And with no regret, remorse whatsoever about the murder that he committed. Which is something I don't think I've ever seen in my life but before which is like, he's not locked away where you can't hit. He's shouting from the rooftops about how proudy as of what he did and seemingly as the support of the people who are You know in his country here appointing him on TV and so on and say the Russian is like have quite a different response, Nationally to the accident and and his involvement in it.

53:24

I don't really know what to say, like it's crazy, it's a crazy story and I think. Good that, you know, let's say this last bit is not really related to TCAS but Is such a dramatic story. I think admit actually being Possibly the most dramatical. Yeah, exactly. Aircraft accident.

53:44

I don't know. Most harrowing , aircraft accident. It then invokes like so much emotion. Yeah, in the people who Survive effectively. But they didn't know how to respond. Either nationally, or on an individual level because there is no explanation, your average aircraft accident, like to me, like a road traffic accident, you know what I'm like about speeding.

54:08

A road traffic accident, you know, with with fatalities. It's just so meaningless. It's like it's not cancer, it's not, it didn't have to happen. Yeah. An air traffic. Accidents are always the same. They're just I think if you lost somebody in one, you would never really understand why on a human level like why is that happened?

54:30

But this one, with all the, the my new Things that came together to allow it to happen. Is even more unexplainable. Does that make sense? Definitely. And so more. Upset in shocking. Yeah, shocking. Yeah. It's a shocking story. So for me, all it does. Really maybe as I've got older is In.

54:56

You know, sad. Sadly, it posts like the human element back into the job. But then, It also shows you that How amazing? We can do. Some some geeks who've probably never flown a plane in their life, like, came up with the algorithm, like in the 60s to detect aircraft, collisions and fit omni directional, aerials to top and bottom of aircraft then And then some genius, you know who knew about the semantics of aircraft displays was like kept flying to the green.

55:29

Yeah. How many lives have been saved like that? Despite that tragic story, TCAS has been a brilliant edition to The aircraft and saved many, many lives and accidents. So long may continue. Yeah absolutely and it's moving promptly just inside the green. Yeah and keep it really simple for those pilots for risk, guys For me.

55:50

Yeah. That's it? Really? That's TCAS. All right. Yes.

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