Kiwi B777 burst 12 tyres in aborted takeoff at NRT
 

News flash :


Air New Zealand is investigating what went wrong with one of its Boeing-777s after 12 tyres burst after a packed flight at Japan's busy Narita airport on Sunday night was forced to abort, sparking a full-scale emergency response.
Flight NZ90 was forced to urgently abort its take-off when the pilots discovered a potential problem with the auto thrust control, the Dominion Post reported.
Twelve tyres on the aircraft burst and fire appliances were needed to cool its braking system, resulting in the runway being shut down for 30 minutes.
Civil Aviation spokesman Bill Sommer said Air NZ had informed the authority of the incident.
An airline spokeswoman confirmed an investigation was under way.
Potential problem with autothrust? Is this one you would reject at high speed?

Autothrust / Throttle Hold?? I wasn't there so I don't know.

12 tires burst? more likely the "melt plugs" did their job and deflated them, a tire burst at 220 PSI {cold }is not an event you want to be close to.

We have one known fact thus far and that is that the takeoff was rejected. The reports of "outcomes" antecedent to the reason for the reject such as "12 burst tires" are not important - they are designed to do that to prevent explosions from pressure build-up due to heat so that is not news. (Nor is a burst tire in and of itself normally a reason to reject a takeoff).

The statement above regarding autothrust is not an established fact. It reads like a media statement. Otherwise your question about rejecting the takeoff would be easy to answer - the answer would be "no, one would not reject a takeoff due to a 'problem with autothrust' ".

However, there have been seven incidents on the B777 aircraft where crews have inadvertently engaged the autopilot on takeoff, one occurring just recently. It is a known issue, which, hopefully, FOQA programs are asking questions about.

We must wait for further details.

PJ2

One assumes Air New Zealand have started using Air France S.O.P's ? ? :rolleyes:

www.avherald.com says

An Air New Zealand Boeing 777-200, flight NZ-90 from Tokyo Narita (Japan) to Auckland (New Zealand) with 296 passengers and 13 crew, rejected takeoff from runway 34L at high speed. When the airplane came to a stand still, smoke was seen from all main tyres prompting attending emergency services to spray the wheels and overheated brakes.

The airport reported, that all 12 main gear tyres deflated due to the brakes overheat. The runway had to be closed for about 30 minutes.

Air New Zealand reported, that the crew received a warning indicating a problem with the auto thrust system and decided to reject takeoff. The airplane was able to taxi clear of the runway before emergency services started to cool the overheated brakes.

A bit disingenuous there.

"12 tyre bursts are not important"! :eek: A properly executed abort shouldn't produce anything like 12 tyre bursts - it is prima facie evidence of an abort above V1 - which would put it in the realm of untested (and thus not necessarily safe) outcomes. :cool:

djfingers- who gives a monkeys:hmm::hmm: After V1 NO ABORT unless the aeroplane is considered unairworthy....

Autothrust fail = High Speed Reject Mmmmm - let's see about this one:uhoh:

Now that's utter nonsense. The variables of aircraft and environmental conditions, as well as piloting technique during the abort, are more than sufficient to result in the potential for fuse plugs melting after a high speed reject initiated from below V1. The only prima facie evidence to be adduced from the above observation might seem to suggest an untested realm of experience with the observer.

ELAC

Bring back the real Autothrottle! The FE!

Reject beyond 80K
 

Unless it was an engine fire, fail or the aircraft was 'unsafe' to fly (as per the QRH), a reject is not recommended beyond 80K.
An auto thrust problem is not in itself, a reason to reject.

Would be quite possible for all 12 fuse plugs to melt after a close to V1 reject is what they are designed to do.
Will be interesting to see what actual problem is I think the auto throttle statement may be for the media. Unless you know the ANZ operating procedures or exactly what the problem was would be hard to know if this type of problem called for a high speed reject or not.

I have to agree with the fuse plugs blowing being pretty much an expected thing.
On the 747 Classic if you brake a touch hard when landing at max weight on a hot day you can get up near the brake temp limit without any trouble. And that's hitting the brakes at a slightly slower speed than a V1 reject, usually at a much lighter weight, and taking far more distance to stop.

You're right ELAC (I like your last sentence!) 18Wheeler is too.
I'd say you guys know what you're talking about.

Not A 777 and it is a long video, but watch the action at 5:30 and 6:01


YouTube - Airbus A340-600 Rejected Take Off

I don't think so.

Tyre Burst?
 

An RTO at V1 and MTOW results in the brakes heating to amazing temperatures. As 18-Wheeler and ELAC and PJ2 quite rightly pointed out the fuse plugs deflate the tyres to stop them exploding with the heat generated by the brakes.

I remember watching the RTO tests for the 777 certification on a DVD ages ago, and all tyres deflating is expected.

The reason for the RTO, well that's another issue, but tyres "bursting" is poor reporting.

777 TRI here- The above is utter cock.

A high speed RTO in a 777-300ER will melt fuse plugs in anything close to limiting conditions.

Indeed we had an ER land overweght using brake three (MUCH less deceleration than RTO) and IT melted all the main gear fuse plugs.

Checkboard, the above is, rather, prima facie evidence of a propensity to shoot ones mouth off without knowing the fact.

As to the reason for the reject. the basic philosophy is that the inhibit systems leaves only Aural Cautions and Warnings for items which should result in an RTO. I can't think of an Auto-thrust caution that is on that list, bu journalism being what it is, I'll reserve judgement till the facts are in.

FWIW, rumor in Narita is that when the pilot flying went to rotate, there was absolutely no response from the control column, just a clunking sound, thereby, no ability to get it off the ground. If that is true, luckily they were taking off on the long runway at NRT...

Wasn't there, haven't talked to the crew, nothing in the press here, just the rumor I heard....FYI, perhaps it's not too much to ask to have a little faith in your fellow pilots.

The gap between V1/VR on the 777 wouldn't allow the a/c to stop at rotate. It was a V1 abort and the plugs did their job. The facts will obviously come out but it is being kept quiet at the moment.

And Checkboard stop talking about things you know nothing about. Listen to the Wizofoz.

Thanks Min- But that isn't exactley right either!!

V1 is usually the minimum GO speed, particularly on a long runway. It's entirely possible that, if a truley unflyable condition became evident at Vr, that an RTO COULD successfully be carried out in a fair proportion of takeoffs.

If what has been said in that he pulled back and nothing happened what was he supposed to do keep the power on and crash at great speed probably killing all or knowing he had a long runway attempt and manage a stop.....tyers as has been said have fusible plugs for the reason to prevent tyres blowing out. There has been much tosh spoken on this thread from some people who know nothing about aviation....listen to those that do!!!! Lets wait for the official reason and real facts come out shall we. As an FE if the driver in front of me pulled back, big clunk and no attempt to get airbourne and we stopped in time I would be buying him more beer than he could drink for some considerable time.

Only if you're fairly light - I wouldn't want to try it with a heavy TOW.

Minimum Wage : The difference between V1 and Vr on a 777 can be very minute. In fact they can and are (dependent on company performance criteria) be the same speed.

Sounds to me to be a normal reject at high speed in a heavy 777. I would expect my 777 after a high speed heavy reject would also melt the fuse plugs. I would be suprised if they didn't!

Nor would you except as a last resort. If there is any truth, however, to the speculation that the aircraft wouldn't rotate, you'd have a fighting chance of staying on the paved surface in a fair number of circumstances. We don't actually go to field-limiting conditions that often, and assumed temperature method does involve extra saftey margins over and above the normal regulatory net limits.

Still, if he's got to Vr, not been able to make it fly, and reacted quickley enough to stop by the end, he's done an outstanding job.

All speculation at this time, however.

Wasn't there a comment from the Crew on the AF RTO about control problems as well (heavy to rotate?)

So far the only one that's implying a stop after V1 is SKMARZ and he heard a rumour; it could well be that his rumour just mixed up the AF at Lagos with this one. After all this is a rumour network but it is a waste of energy to spend the next 10 pages reading speculation on a rumour that never happened and probably is going to be a copy/paste of the AF-thread. Anyone else could confirm this theory?

The 777 OPT does not do a Balanced Field calculation. It does an optimized or improved climb calculation depending on where it is limited. I don't know if the Kiwis have an EFB or if they use RTOW charts. In any case, it very possibly was not a balanced field calcultion so for anyone to suggest that an abort above V1 is not viable is BS. If this is too confusing for you, good. Go to the spotters forum.

They had an incident, no one was hurt, and the a/c can be used again. Good result!!! That's all we know. Pronouncements by wannabes don't further our understanding.

might be of interest

YouTube - Boeing 777 rejected take off (RTO)

Jetjockey
 

JetJockey beat me to it. The RTO test from the series 'Making of the 777' was one of the most impressive and spectactular events in a film full of impressive engineering. I believe they called it 'The Big One', because they knew they would damage the aeroplane, it was dangerous and Cashman was in half a mind not to do it. The test was made even more harsh because they had to rate the P&Ws at something like 104% or even 106% to allow for the Trent engine variants.

From an engineering point of view, in spite of knowing all about carbon fibre brakes, it is still an awesome sight to see how materials can stay together at the molecular level, when subject to stresses like that.

Roger.

...maybe?
 

more of the same?
Air France rejected T/O in Lagos.
Boeing has reported around 15 cases of problem with A/T engagement due to operational misstep by the crew...
Hope not.

I'm fully aware that limiting RTOs may produce deflations and indeed fires, thankyou to you all.

Information quoted from Boeing's Take Off Saftey Training Aid (TOSTA). :rolleyes:

Prima Facie - on the face of it. Sufficient to require further investigation. :hmm:

That means that it's a bit rich to say "12 tyre bursts are not important" :hmm:

On the face of it,no evidence that 12 tires DID "Burst" other than usual media hyperbole. Very small amount of investigation seems to confirm this.

Every reason to believe a standard, well handled RTO resulting in predictable, by-design tire deflation after fuse-plug melt.

Umm, Checkboard - jetjockey737 and Wizofoz beat me to it. Watch the video. As I said before, this is the expected result. The tyres didn't "burst", they deflated because the fuse plugs did the job they are designed to do.

Thanks jetjockey737 - that's the DVD I watched - and I agree landroger, it's a great piece of work.

The unanswered question here is the reason for the RTO.

I want you to handle any investigation I am involved in, Wiz. :ok:

If it was high enough energy to either burst or deflate 12 tyres it would normally be classified as "high" or even "severe" risk in a safety analysis.

Yes in the video they did. You have video of this event?

Not saying it didn't happen, just saying you don't know it did happen.

The fusible plugs are placed on the rims, near the brake assembly in order to react to heat generated from the brake pack. If the heat in the tyre is not generated from the brake pack (i.e. it is generated in the tyre itself during long taxi operation for instance) then the fusible plugs more often than not won't operate (as rubber is a poor conductor of heat, sufficient heat doesn't reach the plug) and the tyre will burst.

Checkboard - I'd rather believe a 777 driver who has explicitly stated his experiences in an a situation that under heavy braking both sets of trolleys deflated because the fuse plugs blew. Whilst this may be unverified, I'll go with it.

I guess what I am saying here is that the tyre deflation (NOT "burst") is secondary to the reason for the RTO. If it was an RTO at MTOW, it's just going to happen. It's part of the rationale for the certification for the airframe.

I landed a A340-600 last week (10 tons below MLW of 259 tons) after a Green Sys Hyd failure leading to Alternate braking. Even trying to brake gently (a little more difficult with Alternate Braking) and using all 15500ft of runway led to several brakes above 650 deg. A MTOW RTO will easily melt the fuse fuseplugs on any airliner certified under current regs.

taxi clear
 

Not making any grand pronouncements here - just a question. Air New zealand reported that the a/c taxied clear. Was that a good idea from an engineering point of view, running on rims must cause extra damage musn't it ? To say nothing of shaking up the pax even more than they already would be.

A few years ago I had a main-gear tyre that disintegrated shortly before V1.

All my training told me to continue the take-off.

If I rejected at this speed, we would only have a fraction of the full length of the runway in which to stop and the braking effort would be reduced due to the damaged tyre.

If we continued and got airborne, we could leave the gear down, complete any required checklists, reduce our landing weight to a minimum and then land on the full length with the fire crews in attendance.

All these thoughts went through my mind in a short time-frame.

While I was pondering this ‘received wisdom’, the aircraft was shaking and vibrating so much that the instruments were unreadable.

We were drifting to the right of the runway, towards scrub and rough ground.

There was still quite a lot of runway remaining ahead.

What did I do?

Did I make the right decision?

What did I learn?

Answers will be posted in a few minutes, so stay tuned!

In the meantime, all the ‘Monday morning quarterbacks’ can tell me what I should have done!

Eckhard - are you sure you weren't landing at YYZ?


I'll get my coat.... :}