Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

by rwmj • 9 years ago

207 142 9 years ago

nabla9• 9 years ago

It's more than just fan blade failure. Engines are tested against fan blade failures. The surrounding cowling should contain it.

In this case the whole fan disk is gone. Uncontained failure like this can down the plane depending on the where the parts fly.

rwmj3• 9 years ago

See also: https://en.wikipedia.org/wiki/Qantas_Flight_32 ... although that happened both in a different part of the engine (the hot bit) and that was a Rolls Royce engine whereas this is an Engine Alliance (GE/P&W) GP7270 engine.

WalterBright11• 9 years ago

For what a failing fan disk can do:

https://en.wikipedia.org/wiki/United_Airlines_Flight_232

hexane3603• 9 years ago

*For what a failing fan disk could do to a DC-10 built in 1973. Since this accident, hydraulic fuses and backup electronic actuators have become standard.

rjsw• 9 years ago

Maybe the cowling did contain the disk failure, it just didn't stay attached to the rest of the engine afterwards.

jacquesm5• 9 years ago

I'm with you on the cowling containing the failure, there is no other explanation why the cowling would disappear as one piece, the amount of force required to shear that module off the front of the engine is substantial. I really hope they will be able to recover the part but I fear we will never know which is going to make puzzling out how this could have happened extremely hard. Though the people working on these cases never fail to impress with their ability to retrieve the story from a pile of fragments you need to those fragments to begin with and the most important bits are missing here.

einrealist• 9 years ago

The fan failure was probably contained by the cowling. But the cowling broke right after because of stresses imposed by the damage and wind. If that's so, the cowling worked. The inner fans look damaged, so I assume the outer fan particles flew through the engine like expected.

userbinator5• 9 years ago

Indeed, you could say that the front fell off. That's not very typical.

noobermin• 9 years ago

I know we're not supposed to upvote or acknowledge jokes on HN, but this was in such good taste I couldn't resist.

hrrsn• 9 years ago

For anyone that didn't get the reference, https://www.youtube.com/watch?v=3m5qxZm_JqM. Worth a watch!

timb072• 9 years ago

It's rare that the funny response is actually more likely to be the accurate response.

One possibility is that the fan shaft failed, and since the fan was no longer attached to the plane that it had been pulling through the sky, it went happily ahead by itself (perhaps still in one piece), taking the cowling with it.

cm2187• 9 years ago

Can't help thinking of El Al flight 1862's weird "engine fell off" scenario:

https://youtu.be/QkWUIaEoUls?t=36m49s

cyberferret• 9 years ago

Seriously lucky that the disintegration didn't take out vital hydraulics or fuel systems in the wing, or penetrate the pressurised fuselage.

I'd like to hope that this wasn't caused by ground crew error, i.e. an improperly secured cowling or access hatch, which snowballed into major component failure...

bad_alloc• 9 years ago

The A380 has two hydraulic systems. If the priamry fails, the aircraft is still fully flyable. Some extra things like slats don't work anymore but those aren't critical for flight and landing. If the secondary hydraulics fail, there are still extra electric actuators to move the control surfaces.

Source: http://www.roger-wilco.net/wp-content/uploads/2010/11/Untitl...

revelation• 9 years ago

I mean, primary and backup hydraulics are hopelessly intertwined on this systems diagram, certainly physically. Not sure how much that is going to help against parts flying into it.

Which is of course what happened in that linked incident below:

https://en.wikipedia.org/wiki/United_Airlines_Flight_232

The three hydraulic systems were separate, so that failure of any one of them would leave the crew with full control, but lines for all three systems shared the same narrow passage through the tail where the engine debris had penetrated, and thus control surfaces were inoperative.

mnglkhn2• 9 years ago

The plane flew for 2 more hours before was able to land.

bb611• 9 years ago

Seriously lucky that the disintegration didn't take out vital hydraulics or fuel systems in the wing, or penetrate the pressurised fuselage.

It isn't luck. It is the result of millions of engineering hours spent on the development of highly reliable and resilient passenger aircraft, an emphasis on public identification and dissemination of design weaknesses, errors, and failures, and an unwavering focus by industry regulators on safety.

This is a particularly egregious failure mode and very hard to contain, but also one which a lot of design hours have been spent mitigating. They were very lucky to have suffered (apparently, as far as has been reported) no significant damage of any kind, but even an extremely egregious uncontained engine failure is frequently flyable because of the emphasis on redundancy in modern plane designs.

WalterBright11• 9 years ago

Sounds like it was over water, meaning they won't be able to retrieve the fan to determine why it failed.

waqf2• 9 years ago

There's some suggestion that it was over Greenland: https://twitter.com/flightradar24/status/914197103026622464.

ScottBurson• 9 years ago

Also: https://www.nytimes.com/2017/09/30/world/plane-engine-explod...

ichadade• 9 years ago

This screams of poor servicing.

jacquesm5• 9 years ago

It does? How can you conclude that without having inspected the missing parts?

It could be a manufacturing defect, it could be all kinds of other things including a design flaw, to conclude that it 'screams of bad servicing' without having any evidence on an incident that is not even a day old is jumping to conclusions.

ant6n2• 9 years ago

"Screams of x" is an educated guess, not a conclusion.

cycrutchfield• 9 years ago

Typically, fan blades failing are due to metallurgical defects during manufacturing. Not sure where you are getting poor servicing from.

tsomctl• 9 years ago

The conclusion of United Airlines Flight 232 was that although it was a manufacturing defect, the maintenance crew should have noticed the crack. Normally, cracks slowly spread over time until the part catastrophically fails, giving you time to catch it using various techniques (ultrasound, x-ray, penetrating dyes).

https://en.wikipedia.org/wiki/United_Airlines_Flight_232

jacquesm5• 9 years ago

Lucky break that didn't happen over a city, that's some pretty serious aircraft droppings and if they had fallen onto a market or a highway hear the point of departure (or anywhere else, but typically aircraft are only overflying cities near airports) it would have been very ugly.

conistonwater• 9 years ago

The passengers report they are still on board of the aircraft about 2 hours after landing because the airport does not have stairs to accommodate the A380.

Does anybody know how this works? Why not just use any old ladder?

jacquesm5• 9 years ago

Risk to the passengers. If there is no imminent risk then it is better to wait for the right device than to risk passengers falling off ladders from 10 meters and higher, the A380 is a huge plane and those doors are pretty high up.

userbinator5• 9 years ago

The A380 is high enough that the ladders (technically airstairs) available probably couldn't even reach the doors.

http://www.tips.si/pdf/Door-Sill-Heights-Passenger-Stairs-24...

Interestingly enough, an A330/340 can be even higher, but only slightly (~30cm).

rpeden• 9 years ago

Makes sense, but I wonder what they'll end up doing. Nobody's going to be driving a set of A380 compatible air stairs to Goose Bay.

cybrjoe• 9 years ago

My guess? Liability.

rwmj3• 9 years ago

At first I was surprised they didn't use the emergency slides, but I suppose once the aircraft is on the ground and there's no evidence of a fire or similar, it's safe so there's no immediate need to deplane the passengers.

dba7dba2• 9 years ago

Ftom all the videos of planes I've seen, I think slides are deployed only when fire is involved. Since the damaged engine didn't start any fire for 2 hours, the pilots probabaly knew there was no need to deploy the slides when they landed.

gvb• 9 years ago

The risk of minor injury (sprains, etc.) is pretty high for slides and there is some risk of serious injury (broken bones and worse). They are used when the alternative risk is death.

userbinator5• 9 years ago

A similar thing happened to a Southwest B737 last year: http://avherald.com/h?article=49d2d7e3

SmellTheGlove2• 9 years ago

It's amazing to me that modern aircraft engineering is so good that an engine can lose its fan blade entirely at 35000 feet and the plane can still continue on for 2 hours and safely land. An uncontained failure like this is the worst kind, and I know it could have gone worse, but it didn't and that amazes me.

I wonder if the cowling contained the initial disintegration but was removed in the process. I'm not an engineer, but from the way that looks and the fact that nothing flew off and did further damage makes me at least wonder if that's what happened.

CydeWeys3• 9 years ago

The A380 has four engines in total, and can easily tolerate the loss of just one in normal flight. Adding more engines has been a basic way to increase reliability since the beginning of the field; it's not just modern aircraft engineering. There's no other part of the airplane behind the engines either, so nothing to be hit by debris.

What amazes me more is that the newest twinjets are now considered reliable enough to fly six hours away from the nearest landing strip -- that's how far they can coast on the single remaining engine if necessary!

inamberclad• 9 years ago

It's not really coasting. A transport category aircraft is required to have enough power to continue climbing if it loses an engine, so it must also have enough power to maintain level flight indefinitely (barring fuel consumption, oil leaks, or mechanical damage from an engine failure)

timb072• 9 years ago

Actually, adding engines increases resilience, or the ability to tolerate failure.

The extra complexity of extra engines actually reduces reliability, since there are more components that can fail.

WalterBright11• 9 years ago

There's no other part of the airplane behind the engines either, so nothing to be hit by debris.

The fans spin very fast, and will fly out radially, not just fall back. They'll slice right through anything they contact. The Airbus flight was very, very lucky.

ansible• 9 years ago

An engine-out situation does get interesting though when the aircraft is low and slow, such as when taking off and landing. That's where good training is needed to recover quickly and successfully.

jasode• 9 years ago

What amazes me more is that the newest twinjets are now considered reliable enough to fly six hours away from the nearest landing strip

Yes, there's also a short video about that: https://www.youtube.com/watch?v=HSxSgbNQi-g

It's very interesting since ETOPS[1] affected the financial bets that Boeing made on 787 (point-to-point) vs Airbus with the A380 (hub-and-spoke).

[1] https://en.wikipedia.org/wiki/ETOPS

SmellTheGlove2• 9 years ago

I wasn't really commenting on adding engines - I know that concept has been around a long time. This wasn't just an engine going down, this was catastrophic failure, and my amazement is in that no other part of the aircraft was affected outside of that one engine.

There's no other part of the airplane behind the engines either, so nothing to be hit by debris.

No, but there's a wing and the fuselage nearby. Again, I'm not an engineer, but I'm assuming that in this type of failure, the part of the engine that's spinning might want to come laterally (is that the right word?), and that seems like it could be trouble. I'm amazed that it didn't.

What amazes me more is that the newest twinjets are now considered reliable enough to fly six hours away from the nearest landing strip -- that's how far they can coast on the single remaining engine if necessary!

Totally amazing. I'm not sure, but is that only the A350XWB for now, or have others been certified past ETOPS-360? It's basically certified to the design limit of the aircraft, so I'm not sure what else has been designed for that. Even 5+ hours is nuts though.

Somewhat related, but check out the Chilean regs on flying from the mainland to IPC/PPT. As far as I know, they still have the one aircraft rule.

rphlx• 9 years ago

The real concern here is not loss of thrust, but rather, what other parts of the airframe are seriously damaged or destroyed by the debris. In the accident record I believe there is precedent for separated engine parts seriously damaging wing and tail surfaces, causing at least partial loss of control.

ajarmst3• 9 years ago

Agreed. When I saw the amount of damage, but little on the wing edge (there may be damage on the underside), I assumed the engine maintained confinement long enough to dissipate a lot of energy. If the cowl was damaged during this, then it may have then come off due to aerodymic stress. Either that or they were very lucky. From the photo I saw, it looks like they lost the forward cowl, fan and maybe a compressor stage. If I had to guess, failure of the low-pressure shaft.

WalterBright11• 9 years ago

I assumed the engine maintained confinement long enough to dissipate a lot of energy.

Not unless the cowling was armored, which it wasn't at least back in the 80's. That thin sheet of aluminum won't even be noticed by the high strength fan spinning at tremendous speeds.

candiodari• 9 years ago

The thing about it is, that these sorts of things get designed because of evolution. Some engine fails in some way, and it gets redesigned. Planes fail, ditto.

And after >100 years of that, we have pretty safe planes.

What most amazes me is that despite the scientific knowledge we "have", we can't design a new engine from first principles directly. We do it through trial and error. Lots of hilarious/horrible error.

KGIII5• 9 years ago

It is kind of nest how they have progressed, as well. It is sometimes little things that make a big difference. It iterative process, I suppose.

Rolls Royce prides themselves on hiring interns. The little cone piece in front of the jet engine had issues with icing up. This had plagued jet engines for years.

They tried all sorts of ways to fix it, including complex methods of supplying heat.

One of their interns just happened to hear about this problem and suggested they simply make it out of rubber. Sure enough, it worked and the problem with that pointy bit freezing was solved.

I'm sure it has a formal name and that it is probably not pointy bit or little cone piece. I don't actually know anything about jet engines, I just watched a documentary about Rolls Royce's jet manufacturing.

Anyhow, that wasn't something that could probably have been designed with first principles. Someone, pretty much in passing, pretty much had to have that creative spark at just the right time and with just the right information.

It's things like that story that make me think humans are going to be in the loop for a long time still and that AI taking over the world is still a long ways away.

yread• 9 years ago

There was also this much discussed incident

http://avherald.com/h?article=46a8f70a

where they just shut one engine down above canada and continued on 3 accross the atlantic to kuwait (they couldn't safely - with enough fuel reserve for multiple approaches and a diversion - reach dubai)

anthonys• 9 years ago

I am fairly sure this was a contained failure. The reports I saw (unofficial) said no blades detached or hit the aircraft.

myth_buster• 9 years ago

Are there any serious dangers of debris falling over settlements in scenarios like these?

gnarbarian• 9 years ago

When you consider the frequency of incidents like this and factor in how sparsely populated most of the world is you'd have far better odds winning the lottery.

stevenwoo• 9 years ago

Columbia broke up over the continental United States and a large number of the pieces that did not burn up in reentry were recovered and no one was hurt on the ground by being hit by debris AFAIK. Not sure of the direct comparison but it seems less likely than getting hit by lightning. https://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaste...

khuey• 9 years ago

Debris from the Qantas A380 engine failure several years back fell on some buildings in Indonesia. Nobody was hurt though.

CydeWeys3• 9 years ago

There's thousands of other more dangerous things you should worry about in your daily life. Like lightning or shark attacks.

Now on the other hand, you could be taken out by an entire airplane crashing, e.g. https://en.wikipedia.org/wiki/American_Airlines_Flight_587

ghaff• 9 years ago

People on the ground were also killed as a result of the Pan Am Lockerbie bombing.

WalterBright11• 9 years ago

Just don't live under the airport approach and departure corridors. (I live under the landing corridor, I enjoy watching the airliners float by overhead.)

Watch out for blue meteorites :-)

rwmj3• 9 years ago

I live near Heathrow, and I usually see 4-6 A380s flying over about lunchtime every day (heading to Asia, I guess). They're pretty spectacular, they almost look too slow/large to fly.

lsh123• 9 years ago

“The dreaded three engines approach”

magnat• 9 years ago

That's the most neutral-point-of-view flight incident news article I've seen for quite some time. The whole site is so refreshingly level-headed.

userbinator5• 9 years ago

AVherald is run by a single person who just compiles reports of incidents as they're received, so there's absolutely no editorialising goes on.

FabHK10• 9 years ago

Yup, it's an absolutely brilliant resource. Simon sometimes injects some dry humour ("Incident: British Airways A388 near London on Mar 13th 2016, free shower in lower deck" [1]), but it's very level-headed, comprehensive, factual reporting. Well worth supporting, btw!

http://avherald.com/h?article=4957cf35&opt=0

yeukhon• 9 years ago

Not exactly the same, but in the summer China Eastern Airlines had to return to Sydney because one of the engines was basically failing apart...

http://www.news.com.au/travel/travel-updates/incidents/china...

BrandoElFollito• 9 years ago

There were questions in the article and one close over here, but no answer AFAIK : how did the move people from one plane to another if they could not desimbark them in the first place?

Is the a way to connect two A380s together? (wild guess)

Narishma• 9 years ago

They transfered them to two smaller planes, not to another A380.

cpncrunch• 9 years ago

The article was incorrect...it was just passenger speculation. Probably the airport just didn't have the facilities to accommodate that number of passengers.

grkvlt2• 9 years ago

They used stairs for a 747 and disembarked from the lower deck doors only. The main reason for keeping pax on the plane was that it is not a commercial airport, and cannot handle customs/immigration for an A380 sized (anything > 15 pax, actually) aircraft. Only when the two new planes were available did they moved pax to them.

benmarks• 9 years ago

Here's a GIF of the landing: https://gfycat.com/VastForthrightBarb

laythea2• 9 years ago

I think I will wait until these A380's are "broken in" before getting on one if I have the choice.

brohee• 9 years ago

10 years not good enough for you? Do you only fly 727?

laythea2• 9 years ago

In aviation, that is new and shiny :)

FabHK10• 9 years ago

A380: first flight 2005, about 215 built

B787: first flight 2009, about 600 built

A350: first flight 2013, about 100 built

Off the three, I'd mostly avoid the 787. I still find the A380 the most comfortable, due to all the space. Lower cabin altitude in 787 and 350 is nice, but doesn't compensate for cramped conditions.

I'm a bit concerned about bleed air. (The high pressure air to maintain cabin pressure comes from the compressor stage of the engines, and could be contaminated with oil/fuel/?, and so far only the 787 has done away with that ("bleedless aircraft").) But, damn, that spacious A380 cabin.

JshWright• 9 years ago

The 787 also has a saner UX for primary flight controls (linked yokes, rather than independent sidesticks).

dominotw2• 9 years ago

This reminds me of aloha 243

https://en.wikipedia.org/wiki/Aloha_Airlines_Flight_243

As a result of the accident, the airplane was determined to be damaged beyond repair and was dismantled on-site

Amazing that one one person lost her life.

Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

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