China Southern A380 Prang LAX

[reverserunlocked]

This popped up on my Facebook feed. No idea what happened, looks like they were in too much of a hurry.

https://scontent-lhr3-1.xx.fbcdn.net/v/t1.0-9/15036395_1469337399761924_3012136905846062915_n.jpg?oh=c7417 0b248a52e73678d92fddcb992e0&oe=58C7B8AE

[Piltdown Man]

This picture just raises a thousand questions. Without more information nobody can make any assumptions.

[ACMS]

I've heard several times in YMML ATC begging the crew to look out the window and wave off the ground crew who were trying to show the pin. Depending on location ATC can't issue a taxi clearance until the Tug reports clear, the Tug couldn't report clear until the wave off.:eek:

The cockpit crew just didn't get it and they sat there for 5 mins until they worked it out.

Obviously they would have happily taxied off without checking the ground crew were clear......luckily YMML local procedures saved the day........now in LAX?

Obviously they don't always look outside......:=

[fox niner]

Why would you look outside? All instrument panels are in front of you.
And besides, why such a hurry? Perhaps they were trying to save 20 seconds on a 13 hour flight. Kudo's!

[Hotel Tango]

Why would you look outside? All instrument panels are in front of you.

I trust that is tongue-in-cheek fox niner. Otherwise you shouldn't be posting on here!

Lots of possible scenarios, so you may all be jumping to the wrong conclusions!

[readywhenreaching]

https://pbs.twimg.com/media/Cw-mMIHXcAAoxFW.jpg
https://twitter.com/JacdecNew/status/797038649942609920

[Basil]

I do believe F9 is demonstrating irony.

We don't know who drove into whom yet, do we? Although that bent towbar is a bit of a give-away.

http://pic.carnoc.com/file/161111/16111109581278.jpg

[A4]

When I'm Line Training new guys I always emphasise - DON'T run the afterstart checklist until you have seen the tug, tow bar and man with the pin cross the line back onto stand......what IS the hurry with some people. You could kill someone so easily.....

[fleigle]

From the link above "China Southern Airlines Airbus A380 (B-6139) #CZ328 damaged by tug at Los Angeles International Airport (LAX)."

I'd say it should read "Tug destroyed by China Southern Airways Airbus A380 at......"
Poor little tug, I'd say thats a write-off.

[None]

When I'm Line Training new guys I always emphasise - DON'T run the afterstart checklist until you have seen the tug, tow bar and man with the pin cross the line back onto stand......what IS the hurry with some people. You could kill someone so easily.....


Wise advice.

[springbok449]

A4,

I would have thought that was part of Normal Procedures and SOP's in most airlines...

[Arewerunning]

no reason to wait for the after start checklist.

Just don't ask for taxi before you receive the hand signal

[fox niner]

It was meant to be ironic, naturally.
At my outfit we MUST have the all clear signal first, and after that, we can ask for the takeoff flaps to be set and the before taxi checklist. No way that we can simply start taxiing.
I hope they are able to review and amend their procedures, without firing everyone on the spot. Please, LEARN from your mishaps, and improve your SOP without blaming anyone.

[G-ARZG]

"With over 20 years of airline service, xxx's tractors are
proven performers. The GT-110 is the largest tractor available
and it is the ideal tractor to handle pushback and towing
requirements for all wide-body aircraft (except A380)"

...so speaks the tractor mfr's brochure

[A4]

@springbok449

Yes, you'd think so but so often you see aircraft calling for taxi whilst the ground crew are still unhitching the tow bar or still under the aircraft. :ugh:

I'm sure a large UK airline had an incident a few years ago where the "lifter" tug broke down infront of the No2 engine after disconnection.....dark, not clear, taxied and dragged the engine over the stranded tug lifter arms - ouch! :ouch:

If you see them all clear, over the line....it won't happen. Simples!!

@Arewerunning

no reason to wait for the after start checklist.

I humbly disagree - one thing at a time - doing the checklist is a distractor. Nothing wrong with after start items/actions (flaps, trim etc) as they are coincident with the ground crew disconnecting everything downstairs - but wait until everyone is clear, then the after start checks and then taxi........K.I.S (Keep It Safe)

[Arewerunning]

sorry, but I do not see the point. Why wait for the hand signal before doing the checklist???? You do the checklist (you are not moving and the park brake is set) then, AFTER you receive the hand signal you request taxi.

I do not see any benefit whatsoever to wait for the hand signal before performing the after start checklist...

Aren't we making simple things too difficult? It's like in my Orange outfit where even trainers in their briefing at LGW they say Traffic and Radio congestion is a threat! I mean, what the hell.

[John Boeman]

When I'm Line Training new guys I always emphasise - DON'T run the afterstart checklist until you have seen the tug, tow bar and man with the pin cross the line back onto stand.. (or at least to a point clear of the aircraft).
There are still airlines where this is not s.o.p? It will be, after they have their first incident. Some people just have to learn the hard way.

[FlightDetent]

Narrow bus OEM SOPs:
1250

Next item on the workflow sheet? You've guessed it: AFTER START CHECK ... COMPLETE.

That being said, I've worked for an airline where this had become "evidence based" SOP on B737 but later lost in woodwork when A320 took over. Someone spotted the above paragraph years later and beat us all over the head with the incident reports of bygone era. Live and learn.

[ManaAdaSystem]

Ahh, so now I know why I have to sit at the gate and wait while it takes forever for the blocking aircraft to move out of the way.
After start check list comes.....after start in my airline. And in my previous airlines.
No taxi request before I get the clear signal from the ground crew.
Works for me.

[mrdeux]

Interesting that everyone has jumped to the conclusion that the crew taxied the aircraft. But, are you absolutely certain of it's position? It looks to me as if it might have been parked on 159, in which case you're not going to be started until pulled forward to roughly abeam 156.

Ground equipment is part of the after start checklist...plus there's a camera.

[FlightDetent]

If only those 9 seconds could relieve you of the agony ... :E

[REMAX11]

@flightDetent:

did it ever occur to you that FCOM is customised? ie different airlines different sops...Some airlines disregards Airbus sops completely and rewrites the procedures. But those have mature pilots and great Flight Ops cultures. It actually makes sense: most of the aircraft manufactures sops are not really thought with safety in mind and, you should know that by now.

The A 320 is especially fitting in the above sentence: for many reasons I have no time to explains the philosophy of SOPS for the A320 were thoughts in a period of crazy mentality that was dominating the airbus certification division in the mid 80s.

Safety was a side benefit of a concept that was trying to extrapolate the pilot from his job.

So: many companies many sops.

Going back to the topic, there is no evidence that doing the after start checklist after the hand signal would add some layers of confort to the safety of the ground crew: it is like saying that we should not be taking off if it is not CAVOK.

So, as you might start to discover there is no advantage whatsoever: by applying the same logic that you bring forward with the checklist after the hand signal, we should never do flight control checks during taxi and, god forbid, Single Engine Taxi Out. Way too dangerous...

More does not necessarily mean an improvement in safety.

[Capn Bloggs]

Absolute rubbish.

[ACMS]

Agree Bloggsy, absolute rubbish.

Rule #1 after start, DON'T RUN INTO ANYTHING, and that includes the poor bloody Engineer....or his Tug.

KISS method.

These things aren't just put in their to inconvience Pilots, they are long established procedures learnt from previous cock ups......to try and ensure these silly mistakes don't KILL ANYONE.

[fatbus]

Obviously no Taxi camera

[Huck]

When dinosaurs ruled the earth and I was a 727 FE, we delayed the After Start Checklist until the wave-off because that's when we pressurized the hydros. Didn't want anyone near the nose wheel.

Now that I'm a captain, my goal is simple: I want to get a letter in my file for being too slow off the gate....

[Huck]

by applying the same logic that you bring forward with the checklist after the hand signal, we should never do flight control checks during taxi and, god forbid, Single Engine Taxi Out. Way too dangerous...


I don't do either. Not on departure, anyway.

[Permafrost_ATPL]

Bit worrying that some people here genuinely ask "why do the checklist after the actions? What's wrong with doing the checklist first?" :eek:

[A4]

I think the comparisons about taking off in CAVOK and not doing control checks whilst taxiing are not valid. When you have personnel working out of sight below the aircraft, you need to make damn sure they're NOT there anymore when you release the parking brake - there's a real chance you can hit something (unlike control checks on a taxiway or a CAVOK departure). One Engine Taxi Departure is fine - just be disciplined and don't rush it. If there's a chance it will be tight timewise - don't do it - simple!

If you're both "heads in" doing the afterstarts you can't easily see what's disappeared outside - did you see the tug+bar+man+pin or not?

At least one instance in the U.K. of a 737 taxiing with the tow bar attached but tug and man clear......how that happened is beyond me.......

I like a stress free day out and keep things straightforward. Chill out - slow down......:cool:

[Kerosine]

My airlines SOPs are to wait to see ground equipment/crew clear, complete the After Start Checklist then request taxi. We're "habituated" to hearing "After Start Checklist complete" followed by PM call for taxi.

Clearly under these circumstances, calling for the After Start Checklist before clearing the ground crew is a big no-no, it's all too easy for PF/PM to default to motor action and request/call for taxi too soon. Throw in some fatigue, slots, delay and/or distractions into the mix while you're at it.

If I'm asked for the checklist before the ground crew are clear... "standby". We all know what our SOPs are, and quite frankly I find it baffling to try and save few seconds ANYWHERE when you have people near running engines.

As with most of these SOP discussions it's entirely academic to most line pilots. Someone's crunching the numbers on which method is safer, the rest is anecdotal. We're flying their planes, we follow their SOPs and take the paycheck at the end of the month :ok:

[Kerosine]

At least one instance in the U.K. of a 737 taxiing with the tow bar attached but tug and man clear......how that happened is beyond me.......

I've had the ground crew disconnect, wave me the pin then hurriedly signal to hold position as we both notice the tow bar wasn't where it should have been, i.e. attached to the nosegear!

[Bleve]

The prevailing assumption in this thread is that the China Southern crew taxied into the tug whilst it was still connected. But do we know for sure? What if the tow-bar failed first and the A380 rolled forward into the tug due to momentum?

[nicolai]

I hope the tug driver got away unscathed. Anyone know his/her status?

I also doubt the towbar bent itself nearly 180 degrees (picture in post 7), I suspect a few hundred tonnes of aircraft did that.

[FlareArmed2]

I've heard several times in YMML ATC begging the crew to look out the window and wave off the ground crew who were trying to show the pin. Depending on location ATC can't issue a taxi clearance until the Tug reports clear, the Tug couldn't report clear until the wave off.:eek:

The cockpit crew just didn't get it and they sat there for 5 mins until they worked it out.

Obviously they would have happily taxied off without checking the ground crew were clear......luckily YMML local procedures saved the day........now in LAX?

Obviously they don't always look outside......:=
Obviously you don't know what you are talking about, and are condescending as well.

I am a Westerner working for a major Chinese airline - not this one. In China, the procedure is to do the After Start checklist, make the taxi call, and then wave the ground crew goodbye before starting the taxi. They do not wave off the ground crew before the taxi call. They do not taxi until they have a wave off from the ground crew. There is no "Ground Crew.... Clear" call in the After Start checklist. Perfectly safe, just different to my former airlines.

Just because you do things one particular way doesn't mean it is the best or even the only way of doing things.

Whether you do the After Start checklist before or after waving at the ground crew is irrelevant and a red herring. Actually checking clear to taxi is vital for any airline and any crew, and mistakes have been made before by all nationalities. Perhaps this thread could focus on aviation safety issues, without the lecturing.

[Capn Bloggs]

Whether you do the After Start checklist before or after waving at the ground crew is irrelevant and a red herring.
Again, absolute rubbish! I cannot believe that some of you jokers think it doesn't matter what order you do this procedure in.

[Basil]

I think that, if you want to be taken seriously, you should moderate your language.

I do whatever the company SOP says.
For instance, no difficulty with running the checklist and holding at: Groundcrew - Clear.

[safelife]

In addition to what FlareArmed2 said, in China you can't get a wave off from the ground crew before you start to taxi, because they simply won't wave back before you have your taxi light on and start moving.
Hence, this procedure works only this way.
With my seventh operator here, and none of them had a procedure to get the wave before doing the checklist.
Also, as already said, in the Airbus world it is perfectly acceptable to do that checklist while taxiing.

[FlightDetent]

REMAX11: Wrong target mate, you're speaking to somebody who's uploaded the updates onto EFBs for several years, and helped derive a way to modify the factory pdf's before FCOMs become data driven. I wrote OEM Airbus in that first post for a reason.

As for the rest of your post, I look at it and my brain pulls the image of captain's face changing one deep winter night 2003, as the redcap screamed through the headset under attack by the nosewheel. The PTT used to obtain the taxi clearance has my fingerprints on it. Until today I do not know what we'd done differently or wrongly.

Thus later I had easily adhered to company SOPs to do C/L only after the wave off, and today happily do the same because my employer is reasonably smart not to change the Airbus OEM book too much. For that very same reason I do make F/CTL checks during taxi and personal stats for SE taxi stands at 92% in, 0,05 out this season.

Feel free to shoot the second round.

Basil: You seem to support his stance and think it matters then? Count me in.

[Hotel Tango]

The prevailing assumption in this thread is that the China Southern crew taxied into the tug whilst it was still connected. But do we know for sure? What if the tow-bar failed first and the A380 rolled forward into the tug due to momentum?

But nobody seems to want to entertain that idea. They prefer to want to argue who has got the bigger, ehm, "tow bar"! :E

[misd-agin]

Does anyone's SOP's call for hitting the towbar? Probably not. So there was probably a breakdown in communication/SOP somewhere.

[REMAX11]

sorry to continue the drift but, I am still looking for a rationale answer to the question: "what added safety provides to initiate the after start checklist only after the clear signal from the ground crew instead of doing the after start checklist, wait for the clear signal and then ask for taxi clearance? "

I mean, is it so difficult to give an easy explanation? I know plenty of airlines (none of them brits, but that is another matter entirely) that do and off course writes in FCOM and OM B exactly the latest and works like a charm.

it's interesting that nobody seems to be patient enough to bring forward a simple explanation on this specific point.

[GAZIN]

From the pictures it looks to me as if the tow-bar is still connected.
Perhaps it was overloaded by a combination of having the engines started before, or during, the push and a high steering angle.

[FullWings]

sorry to continue the drift but, I am still looking for a rationale answer to the question: "what added safety provides to initiate the after start checklist only after the clear signal from the ground crew instead of doing the after start checklist, wait for the clear signal and then ask for taxi clearance?
One reason would be that with a well-designed procedure/checklist you have two chances at getting it right: the procedure (check crew clear) and the checklist (are the crew clear?).

You have to omit both of these to be caught out, as opposed to just a single error in skipping straight to taxi clearance having completed a checklist that didn’t include “crew clear” as an item...

[Kerosine]

You have to omit both of these to be caught out, as opposed to just a single error in skipping straight to taxi clearance having completed a checklist that didn’t include “crew clear” as an item...

That's a very good point but relies on the item being on the checklist.

Concerning the event, could we expect to see any public report published in the future? Or is it all kept hush hush?

[Basil]

Yes, I'd also concur with FullWings point.
It's still the one you haven't thought about that gets you, or not being careful enough, or not being sensitive to concerns of your crew.

[twochai]

it is the ideal tractor to handle pushback and towing requirements for all wide-body aircraft (except A380)

I'm surprised that nobody has commented on the tug manufacturer's brochure statement.

TUG GT110 aircraft pushback (http://www.tugtech.com/tugproducts/tug-pushbacks/gt110-2/)

My bet is on the tug being the offending operator, not the aircraft crew.

[peekay4]

G-ARZG commented on the GT110 (back on page 1 (http://www.pprune.org/rumours-news/586863-china-southern-a380-prang-lax.html#post9575414)).

There were (unconfirmed) reports on social media yesterday that the tow bar snapped during push back, causing the tug to subsequently crash into the nose gear with substantial force.

[core_dump]

And besides, why such a hurry? Perhaps they were trying to save 20 seconds

Perhaps they were trying to be courteous to the other ramp occupants: That's 20 fewer seconds that everyone else has to look at a hideously ugly aircraft.

[Capn Bloggs]

There were (unconfirmed) reports on social media yesterday that the tow bar snapped during push back, causing the tug to subsequently crash into the nose gear with substantial force.
Farcebook "report"?? What is confirmed by the picture is that the aeroplane ran over the tug, not the other way round!

I think that, if you want to be taken seriously, you should moderate your language.

Perhaps if people want to be taken seriously, they shouldn't dismiss, out of hand, a procedure that would in all probability have prevented this. To hop on here, as Flarearmed did, and rip into ACMS' comments beggars belief.

[Icefishing]

G-ARZG commented on the GT110 (back on page 1 (http://www.pprune.org/rumours-news/586863-china-southern-a380-prang-lax.html#post9575414)).

There were (unconfirmed) reports on social media yesterday that the tow bar snapped during push back, causing the tug to subsequently crash into the nose gear with substantial force.
Looks like the tow tug had not completed the push back. From the pictures,the aircraft was not on the center line yet. Not sure whether LAX allows engines start prior to completion of push back.

[ACMS]

Flarearmed:----

Mate, I heard this myself on YMML ground not once but twice. They could not get the flight crew to look out the window and wave off the ground crew.

Second fact:- YMML ATC ( Ground 121.9 ) at most pushback locations for widebodies WILL NOT give a Taxy clearance UNTIL the Tug crew report "Clear" away from the Aircraft and off the taxyway.

Now, I operate a lot in China and elsewhere, it's not normally a problem.

These guys didn't understand ground asking them to wave off the ground crew OUT THE WINDOW, so there they sat.

In my little outfit we have learnt the hard way after mistakes were made, yes mistakes were made and hopefully addressed so PEOPLE DON'T GET KILLED.
We do not action the after start checklist until the wave off, the last item on that Checklist is ----Ground Crew clear, then we request Taxy.......very simple.

It's not rocket science, this procedure was developed because previously mistakes were made.....another Swiss Cheese hole hopefully closed.

It may be fine when you are in the Cockpit mate but it's when you aren't that there seems to be an Airmanship problem.

[ACMS]

Oh and another thing.......

It's not unusual to hear foreign carriers requesting taxy clearance in HKG while the ground crew are still at the nosewheel. ATC have come back and said, "Confirm your ground crew are still connected?"
They too have Eyes and Binoculars and can see....

This practice has to stop.

[Basil]

Yes, a bit like "Ready for start."
ATC notes stairs still on etc etc hence this "Fully ready" stuff we had.

[ACMS]

Yes that happens in HK too.

[Capt Fathom]

Can ATC actually see that much from where they are?

[ACMS]

On certain bays yes directly and other bays with cameras if need be.

[LeeJoyce]

That tug is far too small to push an A380

I wouldn't use it for anything more than an A330 safely

My guess is once the engines started the tug was still at an angle and the plane Pushed the tug

[G-ARZG]

"The Little Tug that Couldn't?"

[TURIN]

My tuppence worth...

Speaking from personal experience when I was almost chopped into small pieces by an ATP and colleagues gripping the concrete with their finger nails when a 747 taxied before clearance and the no.2 engine went over the top of them!

We rely on you guys to follow SOPS to keep us safe.

sorry, but I do not see the point. Why wait for the hand signal before doing the checklist???? You do the checklist (you are not moving and the park brake is set) then, AFTER you receive the hand signal you request taxi.

Some A330 operators set flaps after engine start, this sends the engines to flight idle. Not particularly unsafe perhaps but on a greasy wet night, it's another hole in the cheese.


Perhaps they were trying to be courteous to the other ramp occupants: That's 20 fewer seconds that everyone else has to look at a hideously ugly aircraft.

:D

[SWBKCB]

Perhaps the Japanese custom of the ground crew lining up and waving isn't just politeness? :ok:

[peekay4]

What is confirmed by the picture is that the aeroplane ran over the tug, not the other way round!
What is seen in the picture is solely the aftermath, but not the entire accident sequence.

[short bus]

News reports say the tug driver was treated for minor injuries at the airport and did not require hospitalization.

[parabellum]

LAX also use the stop and tow onto the bay procedure on some stands, maybe this occurred during the aircraft being pulled rather than pushed? Also, whatever happened to the ground crew calling the flight deck over the R/T, "All pins removed, tow bar disconnected all equipment clear, hand signals on the left" which meant that you had to wait to see the crewman on the left giving a thumbs up, where did that all go then?

[NSEU]

It's not unusual to hear foreign carriers requesting taxy clearance in HKG while the ground crew are still at the nosewheel.

At my former workplace, sometimes this was done to beat curfew. Sometimes technical delays brought the departure time too close to curfew for comfort. ATC could not give the aircraft clearance to takeoff if taxy clearance hadn't been given by a certain time before curfew. The engineers/pusback personnel understood the concept, but one or two flight crews had difficulty understanding this (or perhaps didn't feel comfortable bypassing normal procedures) and we had to tow the aircraft back to the gate for an overnight stopover.

[CAR42ZE]

There is nothing worse than seeing 4 Trent 900s or a pair of GE90s burning away as you're trying to get the steering pin out or the towbar off - then wondering whether the crew know if you're actually still under there or not, especially as you can't really still be hooked into comms as you're wrestling with the towbar or chock (depending on headset of course).

[tafel]

Silly question. What was the weather? Ground engineer may not plug in in a headset for push-back under certain conditions (example thunderstorms in the vicinity).

[Confirmed Must Ride]

There have been a number of reported issues with the A380 pushing the tug/towbar after engine start-up. Also at what point where the engines cleared to start? If still on the turn the force applied would also cause the bar to bend.

Also which company was handling? Looks like Swissport tug and Menzies bar

[groundagent]

It looks like tug and aircraft are both connected to the tow bar, so what caused the contact between them? Was this over-steer by tug? Was this jack knife caused by engine start taking place too early (as instructed by ground staff or by capt over eagerness). Was this some type of bypass system failure which somehow resulted in the nose gear straightening during turn? Did anything else hit the bar while under stress during the pushback?

Additionally, the bar is bent in the middle, why did the shearpins not break?

Lots of questions, has anyone heard any rumors of what actually happened?

[FlightDetent]

In addition to the latest posting, and as mentioned earlier (http://www.pprune.org/rumours-news/586863-china-southern-a380-prang-lax-3.html#post9576784): the tug tractor itself is NOT APPROVED for A380 by its manufacturer.

[falcon12]

Another point worth noting is that the GT110 at 50 tonnes weight only has a DBP of 35.3 tonnes. If the A380, which is still attached to it, weighed anything significantly over say 520 tonnes, the tractor wont push it or pull it. Whether this contributes to the end result is not clear at this time.

[Uplinker]

Looking at the photo in #7, the tug cab has been lifted up and pushed sideways, its front left tyre has been deflated, and the tow bar is still connected at both ends and is bent. The tugs wheels are not turned, but are pointing more or less straight ahead.

The tug could not have caused this by driving into the nose gear because if it had, it would not end up 90 degrees to the aircraft, it would be more head-on. You can't drive into something sideways !

So the aircraft must have moved forwards - due to excessive engine thrust or ramp slope - which pushed against the tug and eventually bent the towbar. Then the aircraft hit the tug, turning it and and pushing it sideways, which deflated the front tyre probably by pushing it away from the rim, releasing the air. The tow bar shear pins probably did not let go because the force was mostly along the towbar, not twisting it sideways.

[peekay4]

Again, what we're looking at from the pictures is the aftermath -- not the full accident sequence.

E.g., engine start, tow bar snaps, tug immediately impacts plane / nose gear with high force. Then only afterwards the aircraft moves forward and drags the tug to final position we see in the pictures.

Or any number of alternative scenarios...

[falcon12]

Uplinker
Agree with your summary of the events and would add it looks like the tractor is in 4 wheel steer mode.
Aircraft hit the tractor and no doubt the enquiry will establish how they manged to do that.

[fatbus]

AC moved under its own power without confirming tug released .

[TURIN]

Car42ze

Why would you disconnect the headset before the two bar? As a standard safety procedure I disconnect headset only after two bar and tug a clear of the nose gear area then and only then pull the steering lockout pin after clearance has been given from the flight deck.
1. The lead should be long enough. If it isn't get a new lead.
2. We have a three people on the push back. Driver, headset man and assistant to handle tow bar.

Unless it's a towbarless tug in which case only two are required, driver and headset.

[Bleve]

AC moved under its own power without confirming tug released .

What's your factual source for this statement?

[SMT Member]

Unless it's a towbarless tug in which case only two are required, driver and headset.

In your neck of the woods. Where I am, however, it's all done by a single person. Head-set is of the bluetooth variety, so no cords to contend with. If we're using a tow bar, it's a two-man job. But we only use tow bars as a last resort back-up.

During my time in the business, 9 times out of 10 when a push-back has gone wrong, it's the flight-deck who's been ahead of themselves. That's the main reason a chock is placed in front of the nose wheel before disconnecting tow bar; to minimise the risk of getting run over by a crew, who releases the brakes without clear signal from the ground. Have seen that happen too many times to remember. Funny thing is, when it happens the airline always have a phalanx of excuses, and as good as never revises any procedures as a consequence. But if the handling agent gets it wrong just once, perhaps snapping a shear pin, the airlines want blood, procedure revisions, updated risk assessments, read & signs, staff briefings and what not. We once had an incident just like that, and was hammered by the airline from Atlanta. The very next day, skipper released brakes and the operator on the ground was only saved by the nose chock. I naturally turned the tables and requested the same from Atlanta, as Atlanta did from us. It all got very, very silent after that. Probably around a year ago now, still haven't heard from them.

[Yaw String]

On the subject of checklists,procedures,and taxi clearance....
We are so very procedurally oriented that breaking the chain can often have undesirable results..."Flap 5,taxi clearance "... can go out of the window,if the taxi clearance is given,(and received) during pushback..
This caught me,one night,out of Dubai...made me very grumpy with ATC,until i analysed the real cause of taxi without Flap....Me!...
The correct measure of discipline will help to avoid these issues.

" But for the grace of god":8

[armchairpilot94116]

I imagine a new nose gear is called for.

Tow truck pulling a China Southern Airlines plane at LAX COLLIDES with the aircraft | Daily Mail Online (http://www.dailymail.co.uk/news/article-3929326/Tow-truck-pulling-China-Southern-Airlines-plane-LAX-CRASHES-aircraft.html)

[JammedStab]

From my sources..... ........

APU was inop. Two outboard engines started at the gate. It was gate 159 that requires a nearly 180 degree turn during the pushback onto taxiway C. For some reason, it was decided to return to the gate by tow with the engines still running. While in the tight turn back toward the gate was when this happened. "Brake, Brake, Brake" was yelled to the pilot when control was lost but obviously, by the time brakes were applied the damage was done.

No doubt there is a lot of inertia if you are towing a heavy A380 in a tight turn and want to slow down. Some airlines do have a max number of engines to be running while being towed forward and/or a maximum speed. This could be an example of why.

[msbbarratt]

So it looks like the type of tug involved is significant in this chain of events? I wonder if this was their first time towing (maybe it's easier to get away with it when pushing?) a heavily laden A380 with 2 engines running with the wrong truck, and their luck ran out.

[falcon12]

From what Jamstabbed reported, all the holes in the Swiss cheese lined up when the tractor in use had a weight insufficient to deal with the situation.

I believe, using the tractor performance figures that if shifting an A380, a tractor weight 62,500Kgs or above and good tyres, are the minimum requirements so that the aircraft cant control the operation. A GT110 is, I believe, generally 50 tonnes maximum.

[Derfred]

Given that it appears the tow bar failed, it must be difficult to blame the tug, No?

[Bleve]

... or the pilots for taxiing early. A few apologies are in order.

[Kranky]

I've pushed/towed 100's of a/c. This one's got me beat.
I cannot understand how the tow bar managed to get bent. Whether your pushing or towing the steering bypass pin must be in. The shear pins then fail if too much stress happens.
Did the tow bar simply fail?
If it did it looks like it failed when towing, with the tug reversing.

[mrdeux]

APU was inop. Two outboard engines started at the gate. It was gate 159 that requires a nearly 180 degree turn during the pushback onto taxiway C.

It's only about a 30º turn. The 380s are pushed into C, tail east, and then towed forward until roughly abeam 156 for start. They are not permitted beyond C10 whilst on C.

[JammedStab]

I was told that it was tail west(150 degree turn) which is what I have done in a 777 from that gate. Maybe a pushback direction error was made for whatever reason(possibly by the tug driver used to smaller aircraft on the gate going tail west) which might explain why there was a subsequent tow forward required with a tight turn back toward the gate in order to pushback once again in the proper direction. Or maybe the story told to me was in error.
But a plausible scenario.

[cdmc]

If the towbar failure was the trigger for the accident then it must have been in compression, ie pushing on both ends... perhaps not entirely along the axis.

After that the plane must have moved forwards to hit the tug. Also the fact that the nosewheel is pointing straight ahead seems important

[FixClrEnt]

... perhaps not entirely along the axis.

Surely the load on a towbar has to be along its axis - unless the towbar comes into contact with something else!

[Chu Chu]

It seems to me that if the aircraft was being towed around a curve, the engine thrust (or just the inertia of the aircraft if the tug were slowing) would tend to push the back end of the tug (or the one hooked to the towbar) to the outside of the curve. If the tug were too light and the rear tires didn't have enough traction to resist this force, the tug could spin partway around, in effect jackknifing. At some point in that sequence, the side of the towbar would presumably come up against something it wasn't supposed to.

[peekay4]

Surely the load on a towbar has to be along its axis - unless the towbar comes into contact with something else!
Normally... but say the wrong bypass / shear pins were used... then during turns there could be enough torque on the tow bar to break it.

[NSEU]

...and assuming the aircraft's steering pin was inserted.

On that type of tow bar, does part of the bar pivot if shear pin(s) shear?

(EDIT) Sorry.. crosspost (with previous poster)

[JammedStab]

Normally... but say the wrong bypass / shear pins were used... then during turns there could be enough torque on the tow bar to break it.
Is it possible that the shear pins broke as designed and then the tow bar bent a few seconds later as the incident continued on with the nosegear jamming the bar against the towtruck?

[NSEU]

There were certainly some unsual forces at play here. The angle of the tug, the flat tyre, the tilted tug cab (cabin) ...

Even if the driver kept his foot on the accelerator after the shear pins broke, why would the tug end up at that kind of angle?
The tow bar isn't touching the cab of the tug, so I assume the tyre of the aircraft did the damage to the cab: I assume there would be no twisting forces generated by the bar, because the (tug) end of the bar is usually pivoting.

I've seen the results of pushback/tow incidents, but fortunately none first hand. Some attributed to aggressive tug driving, forgotten steering pins, pilots putting on the park brake without being told, pilots not putting on the park brake (even though they said they had), tug driver heart attacks, tug drivers falling asleep, faulty tug steering ....

[Kranky]

Looking at the photos and hearing some of the comments I'd say this a/c was definitely being pushed around a corner.
I'd say the driver got the turn all wrong and ended up stopping the tug almost under the Captain at 90 degrees to the tow bar with the a/c nose wheel pretty much pointing straight ahead. Probably not much of an issue with the correct tug but as has already been pointed out this tug was not rated to push the A380.
If by this time, a couple of engines were already started, and because the tug was too light and at an angle, the a/c moved forward under its own power. The tug would've been unable to stop it. This would also explain to front tyre being rolled under and, as the front right of the tug contacted to tow bar, would explain the bend in the bar also.
All in all a rectum tightening experience.
The lesson here; don't use an under rated tug.
Just my thoughts, happy to be corrected.

[Kal Niranjan]

... or the pilots for taxiing early. A few apologies are in order.


Still nothing? It figures!:*

[groundagent]

Purely a hypothesis ...

During pushback/tow, the tug lost traction and with wheels spinning the front of the cab hit the towbar (pivot on the pin connecting tug to towbar) and caused the bar to bend as under tension during operations. Bar bent in a similar way to standing on an empty drink can and touching the side of the can, lateral push force on its own probably wouldn't cause bar to bend.

Guessing the aircraft moving forward and the bent bar didn't create enough force for shear pins to break (still connected to aircraft) and as the bent bar allowed the aircraft to move forward over the tug, friction from tug tyres sideways meant the tug was trying to 'roll' so the suspension compressed and the opposite side of cab moves up (possibly in conjunction with the aircraft pushing against cab).

Others have said tug (possible max weight 54T from earlier link?) was not up to the job, could this be the route cause and knock on effects? Loss of traction due underweight tug, wheels spin and tug moves sideways, tug hits bar and bar bends, and aircraft forward momentum continues to bend bar and aircraft hits tug.

Interesting that Menzies bar used and Swissport tug. Who handles China Southern in LAX? Was the equipment borrowed following break down and not really fit for purpose?