Oops! BA804 LHR>BLL slight mishap taxying in this morning ...

[slip and turn]

G-EUPM unfortunately compromised after landing nice and early and then losing taxyway markings I guess on a slightly snowy morning in Denmark:

Passagerfly kører af banen i Billund - TV 2 (http://nyheder.tv2.dk/lokalt/2017-02-07-passagerfly-koerer-af-banen-i-billund)

(as picked up by TV2 News in DK)

[NutLoose]

British Airways plane 'slides' off Billund Airport runway in Denmark (http://news.sky.com/story/british-airways-plane-slides-off-billund-airport-runway-in-denmark-10759284)

http://e3.365dm.com/17/02/992x558/ccfffc5dfea3375ecfcd29dc1331458f7e21a52d77ae2a9974ead9303b7b dc63_3886510.jpg?20170207114847

[readywhenreaching]

taxiway doesnt look good at all..

https://static.standard.co.uk/s3fs-public/styles/story_medium/public/thumbnails/image/2017/02/07/12/snowy-terminal-billund-0.jpg
British Airways plane skids off runway in Denmark leaving London-bound passengers stranded | London Evening Standard (http://www.standard.co.uk/news/transport/british-airways-plane-skids-off-runway-in-denmark-leaving-londonbound-passengers-stranded-a3460476.html)

[slip and turn]

We had a bit of snow in DK this morning which as you can see, settled on car windscreens but it's naturally dispersed from windscreens and the road and grass now even though the temperature is -1C. I don't think that taxiway would have been exactly icy. As can be seen, the bus and a couple of cars don't seem troubled, but there's no doubt whatever that they'll have been on winter tyres;)

If the snow is anything like the snow we had 60 mile north of Billund, there may not even be much of a trace of snow at BLL right now despite the pervading -1 degree C temperature - it disappeared almost as fast as it arrived.

The FR24.com final track including taxy looks slightly dog legged around touchdown area but I don't suppose for one moment that's a very reliable angle or trace to make anything of. The last part of the recorded track does however tally with the final position i.e. near 'M', perpendicular to runway and facing it, having apparently exited 90 degrees to the taxiway safely but then having started toward the runway again from the taxiway via the grass, as seen in the pictures. Slightly odd, but hey ... someone will know why and will tell us when ready;)

I guess we'll have to wait and see what the official report says about where they were headed. Somehow I don't think it'll say anything about skidding off the runway, nor about how huge an A319 is!

[Evanelpus]

The FR24.com final track including taxy looks slightly dog legged around touchdown area but I don't suppose for one moment that's a very reliable angle or trace to make anything of.

Why even quote FR24 when it's been said many, many times the information isn't accurate. You even eluded to that in your sentence.:ugh:

[slip and turn]

Because it is information and it means something - sensible minds can filter what it means and what it doesn't. Head-bangers possibly can't.

[DaveReidUK]

Actually you're both right - up to a point. :O

There is no disputing that the A319 in question, in common with all BA's shorthaul fleet, sends accurate and reliable ADS-B data.

So the trick in interpreting what FR24 tells us here is to believe the data points (of which there are relatively few covering the landing and taxy) and ignore the lines that FR24 attempts to join the dots with (because they obviously can't take into account missing plot points).

Looking at the photos, there doesn't seem much doubt that the final position and orientation of the A319 is pretty much as shown on FR24 - roughly parallel to the runway exit, perpendicular to the runway itself, and pointing pretty well directly towards the tower.

[Airbubba]

And, for the 4:30 pm ground school question, why are some, but not all of the spoilers still up?

[Evanelpus]

There is no disputing that the A319 in question, in common with all BA's shorthaul fleet, sends accurate and reliable ADS-B data.


My apologies must go to Slip and Turn then.

I didn't realize that some airlines send more accurate ads-b information than others. Which probably explains why when at an airport you see the aircraft has landed but FR24 shows it adjacent to the runway in a housing estate.

[flight_mode]

As we can all see from the pictures the aircraft is on the grass so let's drop the FR24 discussion before this thread goes the same way as the 747 one.

[slip and turn]

Evanelpus - no need to apologise, especially to an occasional flash in the pan like me :) - indeed I did happen (me myself, even) to be banging my head against some baffling FR24 data (and planefinder.net) just yesterday in Spectators' Corner as DaveReidUK knows :p

Meanwhile, back at Legoland, just been looking at the webcam on the roundabout just outside the airport (https://www.webcam-4insiders.com/en/weather-Billund-Webcam/13228-Webcam-Billund-weather.php) to see what snow is still hanging around and when it might have arrived ... nothing that settled on the road there ...

Apart from a passing Porsche, no spoilers up there either ;)

... and Airbubba will be along later to collect our best answers for that before we go home - answers which elude me :}

[Airbubba]

I didn't realize that some airlines send more accurate ads-b information than others. Which probably explains why when at an airport you see the aircraft has landed but FR24 shows it adjacent to the runway in a housing estate.

DaveReidUK has pointed out to me that it really is the case depending on how and when ADS-B installations were done on a particular fleet.

I've flown legacy 757's in years past where my nav display came from IRS and radio nav but my ADS-B, TCAS and (maybe) EGWPS used usually better GPS positions.

[FlyingStone]

And, for the 4:30 pm ground school question, why are some, but not all of the spoilers still up?

If the aircraft is on the ground and stopped, the no. 1 spoilers extend with the speedbrake lever.

[slip and turn]

And, for the 4:30 pm ground school question, why are some, but not all of the spoilers still up?Actually that's quite an interesting question that will get some Airbus jockeys flipping back and forth through the manual, I reckon - Good one, (but only one, eh? ;)) Airbubba!

[slip and turn]

Also interesting same aircraft two last year, including one (http://avherald.com/h?article=49f929b0) less than 4 months ago?:
www.aeroinside.com/incidents/reg/G-EUPM (https://www.aeroinside.com/incidents/reg/G-EUPM)
So these things still occur in threes ...

[Locked door]

Anyone else thinking that there was a repeat of the nosewheel steering fault that also occurred in Manchester? This time on a slippery taxiway, I suspect there was very little the crew could do to keep it on the hard stuff.

[mcdhu]

It's only a guess, PF has selected reverse with spoilers armed so Gnd Splrs pop out. Green and Blue hyds dissipate, but Yellow doesn't for some obscure reason so Yellow spoilers (2&4) remain deployed.
Well it is only a guess.

[pilotmike]

Couldn't they give it loads of welly and power it out? :ok:

Grabs coat and exits...

[slip and turn]

Both wellies, or would one do? For'ards or back'ards?

Oh he's gone :E

[JammedStab]

Didn't BA already write off a 747 which according to answers to my queries, did not have a moving map airport display installed in an OPT which could have, and in my opinion, most likely would have enabled the crew to avoid leaving BA with a hull loss on their records.

If so, then you would think that the world's finest airline might have similar for their other aircraft installed. Perhaps, they do. Do they? Are they considering it or is the cost and/or technological too much for them.

Safety has a price, and based on recent events of the last few years, BA is willing to pay that price, at least sometimes. Are they upgrading any aircraft without the moving map displays?

[First.officer]

Didn't BA already write off a 747 which according to answers to my queries, did not have a moving map airport display installed in an OPT which could have, and in my opinion, most likely would have enabled the crew to avoid leaving BA with a hull loss on their records.


depending on the method of compliance, and device used in any Portable EFB set-up, it's damned near impossible to get AMMD (Airport Moving Map Display) approved with the likes of a portable EFB, say using AMC 20-25 as method of compliance, and then satisfying the ETSO-C165a....needs at least an external aerial I would suggest for the accuracy needed for a decent idea of position without any "furyness" or dilution of aircraft actual position. Installed EFB might be tad easier, although guessing that isn't an option fitted for the older 747-400's??.

[Locked door]

JammedStab,

This crew knew where they were, they could see the taxi way, they just couldn't stay on it. I reckon there's a very high chance it was a technical failure combined with a slippery taxiway. It had nothing to do with having a moving map available.

[JammedStab]

depending on the method of compliance, and device used in any Portable EFB set-up, it's damned near impossible to get AMMD (Airport Moving Map Display) approved with the likes of a portable EFB, say using AMC 20-25 as method of compliance, and then satisfying the ETSO-C165a....needs at least an external aerial I would suggest for the accuracy needed for a decent idea of position without any "furyness" or dilution of aircraft actual position. Installed EFB might be tad easier, although guessing that isn't an option fitted for the older 747-400's??.
Flew the 744 with retrofitted EFB with accurate moving map display.

Check other remarks about the conditions. Perhaps inside info. Still would be curious to know if BA has Airport Moving Map Display on all their aircraft.

[Nyx]

It's only a guess, PF has selected reverse with spoilers armed so Gnd Splrs pop out. Green and Blue hyds dissipate, but Yellow doesn't for some obscure reason so Yellow spoilers (2&4) remain deployed.
Well it is only a guess.

How about yellow system failure - 2&4 spoilers drop plus nws failure?

[Max Angle]

Still would be curious to know if BA has Airport Moving Map Display on all their aircraft. No they don't.

[Fargoo]

And, for the 4:30 pm ground school question, why are some, but not all of the spoilers still up?

Alternate spoilers deployed and not deployed - could indicate hydraulic loss. Image pinched as a still from the news report at the start of the thread.

https://s27.postimg.org/w42rijb1v/Screen_Shot_2017_02_07_at_21_31_15.png

[DaveReidUK]

Also interesting same aircraft two last year, including one (http://avherald.com/h?article=49f929b0) less than 4 months ago?:
www.aeroinside.com/incidents/reg/G-EUPM (https://www.aeroinside.com/incidents/reg/G-EUPM)
So these things still occur in threes ...

There's no obvious connection between the two prior events, other than the fact that they involved the same aircraft.

The June 2016 incident was a return to Heathrow following failure of the landing gear to fully retract (not specifically the NLG). The problem was resolved in time for the aircraft to return to service later the same day.

The October 2016 event is the subject of a current AAIB investigation and involved the NLG torque link detaching during the landing rollout, resulting in the aircraft being AOG at Manchester for several days.

I suspect that the Havarikommissionen investigation won't find much in common with either of the above events.

[Carnage Matey!]

Didn't BA already write off a 747 which according to answers to my queries, did not have a moving map airport display installed in an OPT which could have, and in my opinion, most likely would have enabled the crew to avoid leaving BA with a hull loss on their records.

Calling it a hull loss could be stretching it a bit. That aircraft could have been repaired but given that BA were in the process of retiring multiple aircraft from the fleet it was cheaper to use in-house engineering resources to D check an older airframe in the UK and keep it in service than pay someone to repair the aircraft in Jo'burg. They could have gone the Qantas route and paid a huge amount of money to fix a bent airframe just for the sake of statistics but they're running a business and it made more financial sense to retire the broken aircraft in situ.

[hec7or]

it made more financial sense to retire the broken aircraft in situ

This would be termed a "constructive total loss" which like a "hull loss" is an insurance industry definition, the structure of an aircraft is an airframe, only flying boats have hulls.

[Permafrost_ATPL]

How about yellow system failure - 2&4 spoilers drop plus nws failure?

Might be onto something here. Unless it's an older 319 model, where the NWS was powered by the Green system. But it's a good educated guess, which is rare to see on PPRuNe these days :)

[RAT 5]

Do the swirls of snow on the runway indicate the a/c made a 180 for back track? If so, and the taxiway is to right, on the photo, the curious thought is how they ended up at 90 degrees to the runway BEFORE the runoff. The centre 30m of the runway looks clean.
But the tracks from the runway through the snow appear to be just less than 90 showing the a/c was turning left off the runway not right. In that case it is PAST the turnoff.
I apologise if I've missed a previous full description of the landing roll & turnoff.

[slip and turn]

It's a little difficult to visualise RAT 5 unless you know the airport :}

As SLF at this airport and someone who has parked his car in the Long Term car park behind the aircraft tail a number of times, as far as I can make out, the aircraft did not move between the photo in NutLoose's post #2 (http://www.pprune.org/rumours-news/590637-oops-ba804-lhr-bll-slight-mishap-taxying-morning.html#post9667856) and Fargoo's video snapshot in post #26 (http://www.pprune.org/rumours-news/590637-oops-ba804-lhr-bll-slight-mishap-taxying-morning-2.html#post9668454).

That means the swirls you can see in Fargoo's pic are on the taxiway which runs parallel to the runway which is approximately 150m from the runway.

It is possible of course that having reached the taxiway, then being faced with whatever weather effect they reckoned out of their windscreen at the time, the crew may have decided a return to the runway was a more reliable route to the terminal. Although they were right on the tail of FR5172 coming in, no-one was on theirs. The airport is relatively quiet so a backtrack request would have been a fair shout.

Fact is though, whether they were intending to return to the runway or not, they sadly ended up off piste - Denmark is very flat (highest mountain no more than about 150m!) - but very few airports anywhere are wall to wall seamless smooth concrete every way you turn.

If they wanted to do it, the crew would have had to stop to liase with the tower before attempting such, having already vacated once after landing! Maybe they intended turned 180 in what they thought was all still part of the exitway, and intentionally stopped deliberately abeam the 'M' boards before calling Tower, but they were by then on the wrong (western) side of the boards ... and er ... stuck!

Maybe ... all these maybes! ... it's definitely all a bit odd.

738 FR5172 landed just two minutes ahead and exited at the same spot and used the same taxiway, apparently without incident.

[Wycombe]

I see a BA 767 positioned to BLL late last night, presumably in some connection to this incident?

[Unclarth]

Why even quote FR24 when it's been said many, many times the information isn't accurate. You even eluded to that in your sentence.:ugh:
Alluded :-)

[Chris Scott]

Quote from Permafrost ATPL:
"Unless it's an older 319 model, where the NWS was powered by the Green system."

Can't comment on later hulls in the A320 family, but G-EUPM is an A319-100 series with L/G and NWS powered by the Green hydraulic system.

Ground-Spoilers 1 & 5 use Green, 3 use Blue, and 2 & 4 use Yellow.

Slats use Green and/or Blue; Flaps use Green and/or Yellow.

Green system is pressurised by #1 engine ED pump or the PTU (RMP) from Yellow.
Blue system is pressurised by an AC pump or, in emergency, the RAT.
Yellow system is pressurised by #2 engine ED pump, the PTU (RMP) from Green, or an AC pump.

[A and C]

One more time the unfortunate victim is thrown to the wolves by people who are too stupid to know better I doubt if most of them have ever taxied the Microsoft sim on ice let alone a real aircraft.

The crew of the aircraft have my upmost sympathy as a very uncomfortable felling of there but for the grace of god go I. Having operated in the frozen north for a few years now I have on atleast three occasions while taxiing very slowly when without a hint of warning I become a passenger on a jet that a split second ago I was controlling. The worst of it is there is not a clue when the combination of ice, taxiway slope, and wind forces combine with the lack of friction and the inertia to take control from you.

I now taxi on snow & ice like I'm driving miss daisy ( much to the annoyance of Aeroflot) as that way I might just yet get to retirement without sliding off the taxiway, but one thing is for sure I will as some time in the near future slide on ice but if luck and my lack of speed holds I might just stay off the green stuff.

If I was these guys DFO I would ask them to write a very frank report about the incident for publication to warn the pilot community of the hazards of taxing on ice and sent then back to flying without further action, they are neither incompetent or negligent.......... just unfortunate.

[Magplug]

This airframe has a history of NWS problems as proved problematic at MAN a little while ago. The crew vacated the runway onto the parallel taxiway by making two left 90 degree turns to go to the terminal. Unfortunately directional control was lost during the second turn and the aircraft continued to turn left onto the grass. Any available braking was greatly reduced by snow/ice towards the taxiway edges. A probable NWS or BSCU fault is being investigated. They were very unlucky to get that just as they were turning... There but for the grace of God go the rest of us....

[RAT 5]

I wonder? Considering the weather and snow/slush on the ground. B738 after pushback the bypass pin was removed. However the steering tiller did not connect to the nose wheel. A little piece of snow/ice was found blocking the gizmo widgety thingie that should have released and allowed my left hand to offer some encouragement as to where we wanted to point the nose of our steed; but it didn't and we couldn't.

[slip and turn]

It was 'dry' snow and not much sign of slush even on the second day of it here in Denmark.

But yesterday with G-EUPM - no sign of any braking skids whatsoever, just fresh tyre tracks down to the bare earth??

Now Denmark isn't actually the frozen North. Billund is actually further south than Edinburgh (just!).

I was out on my trusty Raleigh in falling snow earlier today, and even on snow covered cycleways and crossing main highways ... I didn't slip or slide even once, even on my summer City Bike tyres, or encounter anything I'd yet call "slush". After I had passed, my trusty bicycle had in fact wet its tyres all the way through to the tarmac leaving a meandering tarmac trail for all to follow, a bit like FR5172 did yesterday, perhaps, two minutes before BA804 arrived, except with less meandering?

So whats this greatly reduced braking at taxiway edges stuff? Did G-EUPM even actually attempt any serious braking before it came to rest? The tracks shown in NutLoose's photo (http://www.pprune.org/rumours-news/590637-oops-ba804-lhr-bll-slight-mishap-taxying-morning.html#post9667856) don't show any sign of braking skid, do they?

I remember may moons ago a lowly DR400 cleared customs at Biggin Hill. Not its passengers and crew, but the whole nose and powerplant and one wing of the aircraft whilst under quite some power during an attempted turn on the apron in front of the customs building (failed turn obviously)! Someone said it was Butch Cassidy's hole in the wall gang, but we knew better ...

A steering problem known only to those familiar with the potential antics of a weird system of springs and dampers used on that particular type was at the root of it ... no hydraulics to speak of.

But this A319 ... what exactly is the real story? Of course we sympathise with the crew because there but for the grace etc., which is why I exclaimed 'Bugger' in the first post, but let's not dress it up in tones more mysterious than it needs to be. I bet the private BA Pilots forum contains the answer - oh wait a minute - they haven't got one on PPRuNe anymore ...

So as PPRuNe's just a rumour mill for the initiated, we'll have to do our best to guess. Is it then that the thing

Got out of control in a taxiway turn due to an unlucky dusting of the wrong type of snow, or
Got out of control in a taxiway turn due to a mechanical or hydraulic steering (and braking?) failure
Didn't get out of control, just ended up in an unlucky less than ideal controlled state off piste with feathers (spoilers) ruffled?

That suggestion that the snow caused braking action problems is surely wobbly? Have a look again at the webcam just outside the airport (https://www.webcam-4insiders.com/en/weather-Billund-Webcam/13228-Webcam-Billund-weather.php) and compare snapshots of today's snow with yesterday's whilst you still have the chance. (You can only look back 48 hours or so). It's colder today than yesterday, but starting overnight 6.-7. Feb, I suggest the snow and wind has been pretty piffling so far cf. real frozen North standards!

[wiggy]

I bet the private BA Pilots forum contains the answer - oh wait a minute - they haven't got one on PPRuNe anymore ...

I hate to disappoint you but even the non-Pprune union hosted private top secret Tufty club eyes only BA pilots forum has not got the answer- discussion of this incident was locked down by the mods very soon after this happened (and so as not to add to the rumours I'll mention that such action is SOP there for any high profile incident, and done for lots of good reasons).

Looks like we will have to wait a few days for credible rumours from credible sources.

[slip and turn]

Understood, wiggy, but does this (http://thebasource.com/?s=g-eupm+issue) count as credible?

Possibly not been a good year for that airframe?

[wiggy]

Time will tell, I really don't know. The "ba source" is generally pretty reliable but it's interesting they are claiming it was a nosewheel steering "issue", whatever that is, on the same day the incident occured. Then again that description could be a catch all to cover anything from a mechanical defect to the nosewheel steering not working due a lack of traction.

As for it being a bad year for the airframe it's interesting to type in the other BA 320 registrations to get a comparison.

[DaveReidUK]

As for it being a bad year for the airframe it's interesting to type in the other BA 320 registrations to get a comparison.

Quite so.

For example G-EUPJ (http://thebasource.com/?s=g-eupj+issue) comes up with 50% more issues on thebasource.com.

It's in the nature of aircraft operations and maintenance that not all of the fleet will accumulate occurrences at the same rate. Trying to read anything into that is pretty meaningless.

[slip and turn]

Meaningless if you are not a statistician, or a fleet manager in possession of the full SP perhaps?

Yup, 'tis true that in this rudimentary test, G-EUPJ yields 50% more "issues" recorded on thebasource.com spread over 5 years than G-EUPM, but notably 17% less than G-EUPM over the time period of all issues recorded by thebasource.com for G-EUPM.

G-EUPM's all occur in just over the past year. How weird is that?

Actually to be balanced about it, there was one more for G-EUPJ in July 2015 that falls out if you use "incident" as opposed to "issue" in your search ;)

I must admit that since I had found this interesting way to search at tea time today, (which I can see you guys have had fun with now too!) I was myself planning on trying one or two other reg numbers of A319/320/321 for comparison. But it was past tea time for me. I did in fact type in one random BA reg no for another type entirely before I bogged off for tea and telly which was the first one that I stuck a pin into mentioned on thebasource.com front page today. That yielded a statistically less significant three "issues" over 5 years.

So what is it about the A319 type that causes so many "issues", especially in the last 12 months for these two aircraft that were both delivered 17 years ago? Bad luck?

Actually of the 44 (?) on the fleet of BA A319s, a search of thebasource.com for a319 issue yields 394 hits - an average of 8 hits per airframe. I haven't found a simple way yet to find the average over a set period.

A search for a319 incident yields just 10 hits including two mentions of the Billund yesterday (one tells us that Jettime Boeing 737-3YO OY-JTD operated as BA805 yesterday in place of G-EUPM; another two hits refer to G-EUPJ smoke in the cockpit in 2015; and another three out of the 10 refer to the memorable G-ErrorsUndOmmissionsExcepted LHR cowling problem in 2013).

A320s and A321s seem to do better on the 'issue' score at something over 5 hits per airframe average.

The two A318s I guess have to be spot on at all times for ETOPS so no surprises there that there are 19 hits for issues between those two since 2014.

So, all in all, yes pretty meaningless - except to those who hold more information and can go digging if so disposed ;)

[DaveReidUK]

In my experience, examination of the technical records for those Airbuses (or any aircraft, come to that) would reveal many dozens, or even hundreds, of "issues" over the years.

Here, we're relying on a blog that, by definition, only focuses on those occurrences that have an external impact (flights delayed or cancelled, forced returns, etc) and therefore only reports on a minute proportion of the total.

That doesn't fit any definition of "statistically significant".

[wiggy]

Here, we're relying on a blog

Point well made, and perhaps one I should have made earlier when I was effectively asked if the BA source was credible.

AFAIK whilst the BA source is excellent for many things it is not an official organ of the company and AFAIK has no official feed from company sources, though it times it is remarkably well informed in some areas. TBF if you look at the website's header it does make it clear it is an unofficial blog.

[Locked door]

For those that haven't seen it here's a demo of how easily your day can go wrong when there's snow and ice around.

https://m.youtube.com/watch?v=4vr3tDyQgTw

[slip and turn]

Back to the frozen north I see at minus 20 degrees C ! But ok it is a salutary warning of what can happen on black ice without skidpan training ;)

[Fursty Ferret]

I have on atleast three occasions while taxiing very slowly when without a hint of warning I become a passenger on a jet that a split second ago I was controlling. The worst of it is there is not a clue when the combination of ice, taxiway slope, and wind forces combine with the lack of friction and the inertia to take control from you.

This. Exactly this. I HATE taxying on ice or snow and am quite proud to be the slowest aircraft on the airfield.

[JW411]

I spent a fair amount of my life flying around Scandinavia at night in the winter. I will say straight away that when it comes to snow clearance, they make us Brits look like very poorly-equipped Boy Scouts. However, there can be some occasions up there when clearing the runway (quite correctly) gets priority over the ramps and the taxiways.

In particular, I can remember landing off a CAT II approach at Landvetter one night and tiptoeing down the taxiway at a snail's pace to the ramp. Fortunately the ramp is a big place there and there was nothing in the way for I lost it and we ended up sliding sedately sort of sideways for about 100 metres or so before I recovered my presence of mind.

So, I have to tell you my favourite Billund story. One of my mates arrived there in the early hours of the morning. It is snowing and snow clearance is in progress. There is also a 30 knot northerly wind blowing (the runway is/was 09/27 and about 9,000 feet long).

He is looking at the fuel so he asks how they are getting on.

"We have cleared half of the runway and the braking action is good".

Get the books out, no problem, we can stop in half the runway so they start an ILS. Halfway down, my mate asks which half they have cleared?

"The North Half" came back the reply! So he now has 9,000 feet by 75 feet instead of 4,500 feet by 150 feet (don't forget the 30 knot crosswind)!

So, "Don't Assume, Check" is always a valid process.

[HamishMcBush]

Could have been worse, they could have replied "The Western half"

[Double Back]

Same discussion in the cockpit when the report of xx% bare and dry in the US was received. Dunno if that is still used there, I was always cautious when hearing this, it meant nothing to me.

[RAT 5]

Interesting: and not wanting to make light of the incident. SAS should be well skilled in such environment, but the apron seems more suited for Torvill & Dean than Boeing. What was the wind, I wonder? The ground vehicles seem OK, but then the would have 'winter snow tyres' & I guess Boeing don't do those.
I wonder what the side load was on the gear. The anti-col light went off just as they stopped. I wonder what they had done to the engines. I'd imagine they'd waited to see where they were when the world stopped rotating. Did they shut down during the pirouette and still have the thought to switch off the anti-col? Cool dudes if they did.

[blind pew]

There was a 747 blown off a taxiway in Anchorage in the 80s...had problems controlling it in a strong wind and decided to shut down the engines...game over.
Interestingly BA had different contamination limits to Swissair and operated into Zurich when all of SR's fleet were grounded...work that one out!

[Airbus38]

It would take an unusual combination of factors to leave the aircraft in the situation it is pictured in if there were no failures, therefore I'll throw my best Sherlock Holmes in to the mix...

Presence of steps at the rear door suggests engines shut down, also spoilers 1/3/5 extended. Now, having at one point made the mistake of shutting down after landing but forgetting to disarm the spoilers, my experience is that all the spoilers stayed up and in order to retract them, it required the Y ELEC pump on with PTU left in auto (that sorted 1/2/4/5) then B OVRD to retract 3. If one wanted to only retract 2/4, that would require both engines off (to avoid B operation), Y ELEC pump on and either PTU OFF, inhibited due to certain criteria being met, or green system failure.

The logic diagram for the PTU suggests that it should run the G system if the Y pump is run on the ground with both ENG masters off, and the NLG shock absorber extended (which can't be clearly seen but best guess is that the nose gear looks like it's still properly extended).

In a roundabout way, and at the risk of being told to wait until the facts come out etc. how about the following as an armchair guess?:

- Aircraft lands normally, ground spoilers all extend.

- Aircraft vacates runway, all spoilers still up, then before 'after landing' actions take place (inc. disarming spoilers) suffers G system problem (LO LVL, LO PR?) and therefore loses control of steering.

- Skids to a halt in the position shown given the slippery conditions. Crew runs through the ECAM, inc. PTU off, decides to shut down in situ, performs the after landing/parking checks but for whatever reason misses the check of spoilers disarmed (lever sitting up only slightly, small note on the ECAM memo lost amongst other items relating to the failure?)

- After shutdown, crew becomes aware of the extended spoilers and decides to disarm the lever and run the Y ELEC pump. This has the effect of dropping spoilers 2 + 4 only.

OK, I'll don my helmet but if nothing else it does the grey matter good to think about the system architecture, I certainly can't come up with too many obvious scenarios that would lead to an aircraft parked half on the grass with spoilers 1/3/5 extended.

[student88]

Has the AAIB report for this incident seen the light of day or are Airbus still coming up with something?

[KelvinD]

I see a BA 767 positioned to BLL late last night
I wonder where they got that from? The last of their 767s went to the scrapyard some months ago.

[Flight Alloy]

Would the plane be capable to taxiing over the solidly frozen ground without any damage?

[CEJM]

I wonder where they got that from? The last of their 767s went to the scrapyard some months ago.

In 2017 when the post you quote was written BA still operated the 767. It sometimes helps to check dates on posts before commenting. ;)

[KelvinD]

CEJM: Apologies. You are quite right. I hadn't noticed the dates and assumed it was referring to current events. As you say, I should have checked.

[Icejock]

Norway>Finland>Sweden>Denmark in falling order is my personal experience in how well the airports in the Nordics are able to clear snow and slush. The Danes are not that used to real winter-ops and it is quite possible they where caught out by some early snow and frost.

[CEJM]

CEJM: Apologies. You are quite right. I hadn't noticed the dates and assumed it was referring to current events. As you say, I should have checked.

KelvinD, no apologies needed! It is an easy ‘mistake’ to make. You won’t be the first one and certainly not the last one.

[kick the tires]

Ground-Spoilers 1 & 5 use Green, 3 use Blue, and 2 & 4 use Yellow.

Slats use Green and/or Blue; Flaps use Green and/or Yellow.


A mnemonic I was taught during groundschool still makes me smile and I still use it recounting the above...

Grab Your Balls You Guys

Works inboard to outboard and vice versa :)

[Jack D]

I don’t know what happened, I wasn’t there, but I’m puzzled by the discussion about moving map displays and Ads B etc. ? Quite frequently taxiways are not as
well cleared or treated as Rwys and a little too much gspeed when exiting a Rwy can cause surprises but not in a good way !