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-   -   BAW492 diversion at Gibraltar (https://www.pprune.org/accidents-close-calls/618789-baw492-diversion-gibraltar.html)

Dawn Patrol 26th Feb 2019 06:40

Don’t know if it’s my eyes playing tricks , but on the second vid the surface of the water looks like it is pretty gusty!

AluminumStructure 26th Feb 2019 06:59


Originally Posted by Flying Clog (Post 10400634)
And the winner is.... RAD_ALT_ALIVE.

From an inside BA source, that's what happened.


Do you mean dual RA failure resulting in Direct Law?

HundredPercentPlease 26th Feb 2019 07:27


Originally Posted by AluminumStructure (Post 10400670)



Do you mean dual RA failure resulting in Direct Law?

No, an FCC fault only apparent when config full.

Balloonrider 26th Feb 2019 08:05

Having flown to Gib for over 20 years it can be a very tricky day out. I doubt it was a failure that caused them to go around as they would have initiated a go around earlier. Only the crew will know if it was pio as a result of the windshere or something more. Winds can change very rapidly and the wind was 090/30g35 it only needs a couple of degrees towards the rock and it would be out of limits. We landed a few minutes before and there was little turbulence but this can change in an instant.


ManaAdaSystem 26th Feb 2019 08:12


Originally Posted by Balloonrider (Post 10400715)
Having flown to Gib for over 20 years it can be a very tricky day out. I doubt it was a failure that caused them to go around as they would have initiated a go around earlier. Only the crew will know if it was pio as a result of the windshere or something more. Winds can change very rapidly and the wind was 090/30g35 it only needs a couple of degrees towards the rock and it would be out of limits. We landed a few minutes before and there was little turbulence but this can change in an instant.


But this go around started quite early?

AluminumStructure 26th Feb 2019 08:30


Originally Posted by HundredPercentPlease (Post 10400686)
No, an FCC fault only apparent when config full.

Interesting. Never heard of that.

msjh 26th Feb 2019 09:05

Far Side
 

Originally Posted by xcris (Post 10400040)
BAW 492 diverted today to Malaga. The video footage is disturbing. Have any one seen something like this, ever before?
Flightradar24 shows the diversion path, but I have no access to vertical profile and speed/bearing.

https://www.airlive.net/breaking-vid...-at-gibraltar/

Gary Larson foresaw this decades ago


https://cimg1.ibsrv.net/gimg/pprune....3151408a96.jpg

Fursty Ferret 26th Feb 2019 09:42

Or maybe it's something as simple as an initial gust rolling the aircraft beyond 33 degrees, disconnecting the autopilot, followed by some PIO before a go-around?

Been flying the A320 series for 10 years+ and have never encountered, nor heard of, the FCC fault mentioned (and it's referenced without any supporting evidence.). I have, on a couple of occasions, managed to introduce a PIO myself and seen it happen from the other pilot. It's very easy to do, especially if under pressure or surprised

Just because something is stated confidently and claims "an inside source" doesn't make it true. Simplest answer is usually the most likely.

Jn14:6 26th Feb 2019 09:55

IIRC, Dragonair had a very similar incident with a 320 at Kai Tak, some 25+ years ago. Was that the same thing as being reported?

autothrottle 26th Feb 2019 09:55

Wind at 2,000 feet was extremely conducive to Wave or Rotor. SFC level wind gusting up to 40kts.

chillpill 26th Feb 2019 09:56

There are 2 'types' of Airbus pilots.

1. Those taught directly by Airbus.

2: Those taught 'in-house' by the Airline.

An old and wise first gen Airbus A320 Captain once told me you can always tell the difference between 1 and 2 as above by watching A320's on approach on a gusty cross-wind day...

The Airbus taught pilots ... the A320 rolls slowly (max 33 degrees AOB), stops, regains wings level slowly but does not overshoot wings level.

The 'in-house' pilots... the A320 rolls slowly (max 33 degrees AOB), stops, then rolls the other way invariably over-shooting wings level... then back the other way. A PIO.

Te difference is the Airbus taught pilots are taught to truly understand the theory AND practice of the 'zero roll rate/1G flight' regime in 'Normal Law'... and that the aircraft will strive to maintain that without any pilot input. By contrast, many 'in-house' pilots, (no blame, just a systemic fact), often with a 'classic' Boeing background, chase the roll deviation with a 'traditional opposite' control input, even though the aircraft is already doing that. But they are in fact 'lagging' that aircraft input... and by the time they sense the side-stick against the roll 'stop', the aircraft is already going the other way... so they chase that... to a developing PIO.

The solution... simply 'let go' of the side stick and let the aircraft flight control software system look after things. It's hard to do (learn (un-learn) pre FBW software), but when you do, flying the A320 series is a hell of a lot simpler... and less likely to result in vids like this.

I am however not saying there was no a FC degrade going on here as a result of a systems failure, but this certainly looks like classic PIO to me.

Magplug 26th Feb 2019 09:56

Politics Before Flight Safety!
 
Making an approach to 09 at GIB with a strong wind out of the east is very demanding. With the draconian airspace restrictions imposed by the Spanish (purely for political reasons) aircraft are forced to fly northbound on a right base for 09 where they are directly downwind of the rock at a height where they are in in extremely turbulent air. Gibraltar requires great respect from the pilot, particularly with regard to wind limitations. In this case the surface wind was quite within limits but the turbulence generated by the stronger 1000' wind on base leg can be so strong that it feels like your teeth are going to fall out just as you fly abeam the dockyard. Passengers.... Welcome to the world of the over-paid and under-worked pilot. On the days where I earn my money - you really would not like to be sat behind me!

As you can see from the graphic, the turbulence that lies just west of the rock in strong easterly winds could be completely avoided by the Spanish permitting straight-in approaches over Algeciras on days like this.

Politics standing in the way of Flight Safety... Who would have thought it!

https://cimg5.ibsrv.net/gimg/pprune....e479076750.gif

Station Zero 26th Feb 2019 10:06

If you believe FR24 data the aircraft was at 0ft before returning to the air. Check the CSV file and the timestamps. Would imagine this is fairly reliable ADSB data for this area.

Whatever happened the EFCS was probably in transition or transitioned to ground mode once it touched down as per design.

Once in this mode sidestick input and control output is essentially direct.

During the climb out the flight controls progressively returned to normal law and probably helped null out the oscillation.

As such, doubt anything was wrong with the aircraft, just a reactive input at the wrong time in response to an external event which led to the fairly dramatic oscillation seen.

The fact that the aircraft re-positioned to London after only 5 or so hours would suggest that whatever happened it wasn't a major fault as well. As if it was downloading flight data, analyzing it and discussing possibly with Airbus would take much longer that.

Out of curiosity and not to be picky whats the talk of an FCC on an A320 series aircraft? The EFCS main LRUs are ELACs/SECs/FACs/FCDCs and they all have specific functions within the overall EFCS.

ManaAdaSystem 26th Feb 2019 10:14


Originally Posted by Magplug (Post 10400803)
Making an approach to 09 at GIB with a strong wind out of the east is very demanding. With the draconian airspace restrictions imposed by the Spanish (purely for political reasons) aircraft are forced to fly northbound on a right base for 09 where they are directly downwind of the rock at a height where they are in in extremely turbulent air. Gibraltar requires great respect from the pilot, particularly with regard to wind limitations. In this case the surface wind was quite within limits but the turbulence generated by the stronger 1000' wind on base leg can be so strong that it feels like your teeth are going to fall out just as you fly abeam the dockyard. Passengers.... Welcome to the world of the over-paid and under-worked pilot. On the days where I earn my money - you really would not like to be sat behind me!

As you can see from the graphic, the turbulence that lies just west of the rock in strong easterly winds could be completely avoided by the Spanish permitting straight-in approaches over Algeciras on days like this.

Politics standing in the way of Flight Safety... Who would have thought it!

https://cimg5.ibsrv.net/gimg/pprune....e479076750.gif

I see the problem, but the videos show the aircraft climbing straight ahead, not turning right. It looks to me like they went around from finals. Or did they climb straight into prohibited airspace?
I’ve flown in rotors, waves and severe turbulence, and I never had any steady oscillations in roll like this.
Flaps 40 in gusty conditions (800 NG) may trigger PIO but not in a slow, regular way like this.
It simpy doesn’t look right.

ManaAdaSystem 26th Feb 2019 10:15


Originally Posted by Station Zero (Post 10400813)
If you believe FR24 data the aircraft was at 0ft before returning to the air. Check the CSV file and the timestamps. Would imagine this is fairly reliable ADSB data for this area.

Whatever happened the EFCS was probably in transition or transitioned to ground mode once it touched down as per design. Once in this mode sidestick input and control output is essential direct. During the climb out the flight controls progressively returned to normal law and probably help null out the oscillation.

Doubt anything was wrong with the aircraft, just a reactive input at the wrong time in response to an extenal event which led to fairly dramatic oscillation seen.

Out of curiosity and not to be picky whats the talk of an FCC on an A320 series aircraft? The EFCS main LRUs are ELACs/SECs/FACs/FCDCs and they all have specific functions within the overall EFCS.

Yes, trust FR24 and not the videos that show a goaround from nowhere near the ground.

Station Zero 26th Feb 2019 10:37


Originally Posted by ManaAdaSystem (Post 10400820)


Yes, trust FR24 and not the videos that show a goaround from nowhere near the ground.

That's why I said if you believe it.

Although as it is ADSB information (most likely) and the rest of the flight looks pretty normal the digital data must not have been interpreted/received correctly for the few "crucial" moments of this flight.

The data is Mode S extended squitter direct from the ATC transponder on the aircraft and as long as you have the correct equipment anyone can receive it. No encryption at all.

I think a video that shows the whole approach would be better as don't think the videos above show the full story but instead the most dramatic aspects, better for the press that way.

Nil by mouth 26th Feb 2019 10:37

As a Gibraltar resident I've been on quite a few go arounds especially in the days when it was not permitted to divert to Málaga.
In the days of GB Airways it was not unusual for two or three attempts before having to divert to Rabat or Faro.
One got used to the 'first timers' to Gib with the screaming and white knuckles. Would I be correct that sometimes after a go around or two that the reverse thrusters were deployed just as the landing gear touched the runway....or maybe a little before??

HundredPercentPlease 26th Feb 2019 10:55


Originally Posted by chillpill (Post 10400802)

I am however not saying there was no a FC degrade going on here as a result of a systems failure, but this certainly looks like classic PIO to me.

In my 15 years on the 320, I have seen some cracking PIO but never anything even remotely approaching that. Also, miraculously, the PF learns how to not PIO as soon as they transition from W/S escape into G/A and set Config 3. All points to something odd going on when Config Full.

The previous OEB for this was meant to be fixed with an ELAC software update. As one previous poster said - looks like it has come back to haunt us.

Just the fax maam 26th Feb 2019 10:56

This is a previously encountered and documented error on the A320 family, investigated by both the Canadian and Hong Kong Authorities amongst others, resulting from flap lock in full config G/A with strong cross wind gusts IIRC, supposedly fixed via a major software update, evidently not yet resolved for all potential situations?

DaveReidUK 26th Feb 2019 11:29


Originally Posted by ManaAdaSystem (Post 10400820)
Yes, trust FR24 and not the videos that show a goaround from nowhere near the ground.

Quite so.

ADS-B transmitted altitude data isn't corrected for QNH, so unless you can be sure that a correction has been applied at some later stage you can't rely on the altitude you're looking at being AGL/AMSL.


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