This group has just disembarked after a 27 May A380 flight from Airbus’ Toulouse base.
The flight was mounted to demonstrate two really clever and seriously useful avionic advances that Airbus is just about to see certificated. One will make airborne collision a little less likely, the other will prevent runway overruns. Overruns are the most common type of aircraft accident, and one of the most expensive.
The team in the picture (above) consists of some technical journalists – including me (on the far left) - and numerous Airbus engineers and test pilots all of whom have played their part in bringing these development programmes to fruition.
The skipper on this flight – he’s the 6th person from the left wearing the blue tie - was experimental test pilot Claude Lelaie.
During the flight we carried out a number of full-stop landings to demonstrate the aircraft’s brake-to-vacate (BTV) system, but also to show off an amazing extrapolation of the BTV’s inherent capabilities which - for me - was the day’s showstopper: it was ROW/ROP – the runway overrun warning and protection system.
And, finally, we witnessed – in action – a new way of making TCAS resolution advisories (RA) more manageable for pilots. More of that later.
BTV allows the pilot to pre-set the runway exit at which he wishes to turn off, so the aircraft’s braking system arranges smooth reduction of runway speed down to 10kt with 50m to go to the exit – unless the pilot wants to intervene because it’s a fast-exit taxiway and he doesn’t need to exit that slowly.
This may sound a like the ultimate in unnecessary optional extras, but it would be incredibly useful, especially in poor visibility, for minimising runway occupancy time.
How does the aircraft’s braking system know where the exit is? GPS, of course.
Now, imagine you’re flying your A380 and you are on short final approach to runway 32L at Toulouse. I’m sitting in the back watching your performance on these two displays (below) on a rack of monitor instruments. At the moment you’re doing nicely:
The right image shows split shots from two video cameras, one beneath the belly and another on the fin. In the former, the nose-gear is obscuring the runway threshold.
The left image, absolutely contemporaneous with the video, shows the aircraft’s position relative to the runway (the magenta aircraft symbol). Sorry I didn’t get a video of this because if I had you would be seeing the two images – the real world and the runway plan - moving in synch.
Here’s a picture of the same scene taken from the flight deck, but from a little further out:
…and here’s me (below, left) keeping an eye on you from the back (I can see all the flight deck activity – you’re on video):
Now let’s have a look at ROW/ROP and what it will do for you. Here’s the control that will enable you to tell the aircraft what you want the brakes to do:
If you want BTV, you select it. If you just want a normal landing you select the braking action you want.
Now here’s a picture that will enable us to identify the essential offerings available:
Just before your top of descent briefing you’ve called up this image on your navigation display so you can choose the landing you want at Toulouse. You’ve toggled the cursor (magenta chevrons) onto the threshold of runway 14L and clicked. That has designated the runway, and up comes the magenta crossbar that tells you where your landing roll would come to a full stop if the runway was dry, and a second – further on – if it was wet. That’s ROW/ROP working for you. If the runway was too short the crossbars would be in the overrun.
If you had selected BTV for the brakes, you would get the same display, but having designated the runway, you would have then to move the cursor over the image of the exit you want, and click to designate that.
Smart, eh? But it’s also easy to use.
The Southwest pilots who overran at Midway on a snowy night would have given a lot for something like this.
But it gets better.
When ROW/ROP gives you those stopping point designators for your top of descent briefing, it assumes you will fly a standard profile at standard reference speeds, crossing the threshold at 50ft and putting the beast down in the touchdown zone. But it still works if you don’t do any of those.
If you are high and fast on approach, ROW/ROP knows, and the stopping point designators move away from you down the runway. If you then carry out an extended flare as well, they may move beyond the runway end and, if they do, you will get two warnings: one scripted on the primary flight display saying “runway too short”, and a recorded voice saying the same words.
What I tell you now is not strictly relevant, but I was struck by it just the same: the voice that tells you “Runway too short” (or alternatively “If wet, runway too short), is highly compelling because it’s different: it’s not one of those dead-pan, mid-tone, American-accented voices. It’s a male voice, but pitched-up, and with an exquisitely English English accent. Your invisible guardian sounds as if he is looking over your shoulder and is genuinely worried about what he sees.
It would make anyone go-around.
But if you elect not to go around, when you touch down the system gives you absolutely maximum braking for the conditions.
Anyway, ROW/ROP is fantastic, and the same capabilities and logic that generated it could be used to create a take-off performance monitoring system, something lots of people have tried to do before and failed. My guess is that Airbus will go there, but they are certainly not admitting it.
Now let’s look at the TCAS (traffic alert and collision avoidance system) improvements. Project leader for the programme, Paule Botargues (below), is explaining the system to us before the flight:
Botargues and her team haven’t tampered with TCAS itself, they have just integrated TCAS with the autopilot and the flight director. It’s easy for me to say, blithely, that the team had merely to integrate these functions, but the task is actually very complex because it entails so many systems, inputs and so much software.
Remember that, at present, if the crew receives a TCAS RA, they disconnect the autopilot and fly the vertical RA trajectory manually.
Now the result of Airbus’ work is that, if the autopilot is engaged when an RA is generated, unless the pilot disengages it the autopilot will fly the RA trajectory precisely as demanded. If the pilot is flying manually at the time, he does not have to transfer his attention to the TCAS RA indicator and fly according to that, he just follows the flight director in the normal way and thus performs a perfect RA trajectory.
To test and demonstrate the system, the the team has rigged up a system that generates virtual conflicting traffic on the TCAS display, causing it to provide the usual sequence of visual traffic proximity awareness, followed by a traffic advisory and finally a resolution advisory. This picture I took in flight is not very good, but on the nav display you can see the yellow aircraft symbol (our A380) and the red “conflicting aircraft” just ahead of it that has generated a “climb” RA.
Studies show that pilot reaction to RA is frequently slow, but when the action finally comes it is almost always an over-reaction, occasionally dramatically so, resulting in altitude deviations that are hazardous in their own right.
The TCAS RA indicator (see on the right of the image below) is not easy to fly accurately, especially when the pilot is psychologically aware that failure to follow it may result in a terminal collision:
So this new system, which Airbus calls AP/FD TCAS mode, makes sublime sense.
Just before I sign off I’ll share a little anecdote about this demo flight.
One of the technical journalists that had come along to test-fly the new systems was a recently retired Delta Air Lines Boeing 777 pilot called Earl Arrowood who had never flown a fly-by-wire Airbus of any kind in his 30,000h career. And like the three other journalist/pilots there that day who were taking turns in the left hand seat, this hoary old Georgian aviator was given no simulator time to prepare for the experience, but blithely carried out several approaches, full-stop landings and take-offs.
You want to know what he thought about flying this giant, sidestick-controlled Airbus after a lifetime of McDonnell Douglas and Boeing? I asked him afterwards – although I didn’t really need to because he was so enthusiastic about it. He told me he loved it, and it took him “less than a minute” for him to forget he was flying a sidestick.