
Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated - rwmj
https://avherald.com/h?article=4af15205
======
SmellTheGlove
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.

~~~
CydeWeys
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!

~~~
WalterBright
> 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.

~~~
cialowicz
The engines are designed so that a detached fan blade stays contained within
the cowling. Here's a video of a fan blade containment test on a Rolls Royce
Trent 500: [https://youtu.be/RIOWjhjC1jM](https://youtu.be/RIOWjhjC1jM)

~~~
kogepathic
_> The engines are designed so that a detached fan blade stays contained
within the cowling._

Yes, but uncontained failures can and do happen. Qantas Flight 32 is an
example of an uncontained engine failure on an A380, though with a Rolls Royce
engine instead of Engine Alliance (GE + P&W). [0]

I do think they're very lucky that this uncontained engine failure didn't
cause more damage. QF32 was heavily damaged by debris coming out of the
engine, so the fact that this seems to be relatively contained to the engine
itself is fortunate.

[0]
[https://en.wikipedia.org/wiki/Qantas_Flight_32](https://en.wikipedia.org/wiki/Qantas_Flight_32)

~~~
gmueckl
As far as I have picked up on that subject, passenger aircraft have multiple
layers of protection against blades separating from the engine. The cowling is
supposed to contain it. If that does not work, the fuselage in the area of the
wings is hardened to prevent the separating part(s) from entering the
passenger compartment and doing damage there. This is typically implemented
using a Kevlar lining on the hull.

The Quantas flight is remarkable in that engine parts were not contained
successfully and managed to damage critical systems inside the wing not
related to the engine itself. Some reports say that the flight crew was
overwhelmed by over 50 individual failure reports resulting from this damage.
I was actually quite surprised when I learned that it was so easy to damage
that many major systems with a seemingly small puncture in a wing.

~~~
JumpCrisscross
Keep in mind that the Quantas failure, while horrible, resulted in zero
fatalities.

~~~
bdamm
Very remarkable indeed, considering the damage to the landing gear, flaps,
fuel tanks, and engine controls. The airplane at the time it landed was way
out into the experimental flying zone.

When people talk of pilot-less airliners I have to think of incidents like
this. Pilots do make mistakes and people die as a result, but when equipment
fails and nobody dies because a pilot does what is needed to land safely
despite the issue, it rarely makes news. Sometimes people on board don't even
know.

~~~
justinjlynn
> Sometimes people on board don't even know.

That's the ideal general case. You really don't want hundreds of panicked
people trapped in a broken tin can thousands of feet above ground while you're
trying to handle the situation.

~~~
FabHK
At least you (as a pilot) are behind a solid locked door in that scenario.

However, that brings up another question I've been wondering about: Could the
pax/cabin crew of an airplane collaborate in bringing a jet down, by e.g. all
together going to the very front of the plane (near the cockpit door), moving
the trim up, then all running to the very end of the plane, bringing it into
an uncontrollable stall?

I haven't really seen a satisfactory answer to that question. See Quora and
Stackexchange (where I attempted an answer):

[https://www.quora.com/Would-a-passenger-jet-stall-if-all-
the...](https://www.quora.com/Would-a-passenger-jet-stall-if-all-the-
passengers-rushed-to-the-back-of-the-aircraft)

[https://aviation.stackexchange.com/questions/2507/can-
passen...](https://aviation.stackexchange.com/questions/2507/can-passenger-
movement-in-an-airliner-make-it-stall/37661#37661)

------
nabla9
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.

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

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

~~~
Judgmentality
[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)

It doesn't say anything about jokes.

~~~
anyfoo
I think the unspoken agreement is that nobody wants HN discussions to turn
into reddit with its overabundant pun threads and "funny" one liners. But this
one was on point.

------
cyberferret
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
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...](http://www.roger-wilco.net/wp-
content/uploads/2010/11/Untitled-110.jpg)

~~~
revelation
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](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._

~~~
eesmith
As your reference points out: "Newer aircraft designs such as the McDonnell
Douglas MD-11 have incorporated hydraulic fuses to isolate a punctured section
and prevent a total loss of hydraulic fluid."

A quick search for "A 380 hydraulic fuses" finds sources like
[http://www.airliners.net/forum/viewtopic.php?t=765509](http://www.airliners.net/forum/viewtopic.php?t=765509)
:

> If one or both hydraulic systems fail, the following hydro-electrical
> backups remain available: For flight controls: The Electrical-Hydrostatic
> Actuators (EHAs) and the Electrical Backup Hydraulic Actuators (EBHAs) For
> braking and steering: The Local Electro-Hydraulic Generation System (LEHGS)"

That's depicted in the image bad_alloc showed.

And, "hopelessly intertwined"? Is that your viewpoint as a software developer,
or are you an aircraft designer? Because I'm sure that an outsider would see
my code as "hopelessly intertwined" even when it isn't.

~~~
inferiorhuman
> And, "hopelessly intertwined"? Is that your viewpoint as a software
> developer, or are you an aircraft designer? Because I'm sure that an
> outsider would see my code as "hopelessly intertwined" even when it isn't.

Even with modern aircraft, even with the A380, when a fan lets go or the
engine grenades bad things happen.

Qantas Flight 32, an A380, suffered a UCE and everyone was very lucky that
there were additional, experienced pilots on board. Take a look at the ATSB
report. Pretty much everything that could fail, did. Engine control for the #1
(IIRC) engine had been destroyed and it took the firefighters three hours to
pump enough water to shut down the engine. Without the extra crew things could
have gone very differently.

British Airways 2276, a 777 -- a plane that has an excellent safety record,
suffered a UCE and the plane caught fire. Luckily the pilots were able to
abort the takeoff, but fire on a plane is about the worst possible failure
mode.

AA #383, a 767, also suffered a UCE on takeoff that resulted in a massive
fire.

Cameroon Airlines Flight 786, same deal. UCE, punctured fuel tank, fire.

So, yes, things have almost certainly gotten better but given how much energy
is released when a high bypass turbofan lets go, it's pretty damn hard to
design something that's completely failsafe.

~~~
eesmith
Sure. But do all those correct statements mean that the A380 hydraulic control
systems, and their backups, are "hopelessly intertwined" to an aircraft
designer?

~~~
inferiorhuman
> Sure. But do all those correct statements mean that the A380 hydraulic
> control systems, and their backups, are "hopelessly intertwined" to an
> aircraft designer?

I'd hope so, given that all the redundancy didn't prevent an engine control
failure on the A380.

~~~
eesmith
I don't see your point. Redundancy is meant to make things more survivable in
case of failure. It is not meant to prevent failure. Everyone survived.

As for Qantas Flight 32, which I believe is the engine control failure you are
referring to, my reading of
[http://www.atsb.gov.au/media/4173625/ao-2010-089_final.pdf](http://www.atsb.gov.au/media/4173625/ao-2010-089_final.pdf)
says that only one hydraulic system, Green, was damaged. The redundancy
worked.

> Damage to the wiring also resulted in the loss of monitoring capability of
> the Yellow hydraulic system engine-driven pumps on the No. 4 engine and the
> crew disconnected both pumps as per the ECAM procedure. The Yellow hydraulic
> system was powered by the No. 3 engine for the remainder of the flight. The
> Yellow hydraulic system maintained 5,000 psi for the remainder of the flight
> and subsequent examination found no fluid loss.

The inability to shut down engine #1 was due to "[d]amage to wiring looms
located in the left wing and the fuselage belly fairing."

Again I ask why "hopelessly intertwined" is a meaningful description for the
A380 hydraulic control systems.

------
benmarks
Here's a GIF of the landing:
[https://gfycat.com/VastForthrightBarb](https://gfycat.com/VastForthrightBarb)

------
userbinator
A similar thing happened to a Southwest B737 last year:
[http://avherald.com/h?article=49d2d7e3](http://avherald.com/h?article=49d2d7e3)

------
magnat
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.

~~~
userbinator
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.

~~~
FabHK
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](http://avherald.com/h?article=4957cf35&opt=0)

------
jacquesm
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.

------
BrandoElFollito
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)

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

------
yeukhon
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...](http://www.news.com.au/travel/travel-
updates/incidents/china-eastern-airlines-airbus-a330-turns-back-to-sydney-
after-hole-torn-in-engine-cowling/news-story/d3aefb53f996b9c1ee9d89a34020e757)

------
dominotw
This reminds me of aloha 243

[https://en.wikipedia.org/wiki/Aloha_Airlines_Flight_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.

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

~~~
waqf
There's some suggestion that it was over Greenland:
[https://twitter.com/flightradar24/status/914197103026622464](https://twitter.com/flightradar24/status/914197103026622464).

------
lsh123
“The dreaded three engines approach”

------
ScottBurson
Also: [https://www.nytimes.com/2017/09/30/world/plane-engine-
explod...](https://www.nytimes.com/2017/09/30/world/plane-engine-
explodes.html)

------
conistonwater
> _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?

~~~
jacquesm
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.

~~~
rpeden
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.

~~~
21
They can bring a fire ladder.

They could also use the self-inflatable chutes, but those are likely to create
injuries, so they are an option of last resort.

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

~~~
CydeWeys
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](https://en.wikipedia.org/wiki/American_Airlines_Flight_587)

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

~~~
FabHK
And quite a few when El Al 1862 crashed into a building near Amsterdam Shiphol
airport (both engines on one side of the cargo 747 had come off, plus leading
edge of the wing, and when they later slowed down for landing, that side
stalled irrecoverably :-/

But that's not debris, that was a whole damn 747.

[https://en.wikipedia.org/wiki/El_Al_Flight_1862](https://en.wikipedia.org/wiki/El_Al_Flight_1862)

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

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

------
ichadade
This screams of poor servicing.

~~~
jacquesm
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.

~~~
ant6n
"Screams of x" is an educated guess, not a conclusion.

~~~
jacquesm
An educated guess is something entirely different than throwing out the first
thing that comes to mind in a complex situation. Evidence, not guesses is
where it is at.

~~~
ant6n
I'm merely pointing out that the parent mischaracterized the statement as a
conclusion. It's just a guess. (it's also an unnecessarily adversarial post)

You are trying to counter my observation about terminology, guess vs
conclusion, by saying that evidence is better. Not really relevant.

