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Qantas Airbus A380 engine failure in 2010 (2023)

admiralcloudberg.medium.com

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Re: Qantas Airbus A380 engine failure in 2010 (2023)

#111
post #107

Earlier quoted context omitted.

> A 70kg chunk of nickel alloy is very dense, and at 800m/s , that’s 20 MJ. > For comparison, a modern 120mm artillery shell fired from a tank or similar ... Yes. But when the goal is kinetic penetration of modern armour, they don't use artillery shells. Instead - https://en.wikipedia.org/wiki/Armour-piercing_fin-stabilized... - which bear no resemblance to a failed turbine disk. And have about twice the muzzle veloc…

Good counterpoints all, I think. I’m impressed that we could write off 50t and still have an airplane. That seemed so preposterous that I did not consider it, honestly. Turns out big stuff is big. Now we can go to the running of the bulls with our respective napkin backs, and see who attracts the bull!

> Now we can go to the running of the bulls with ...

Thanks, but I think I'll be running with the chickens. ;)

Re: Qantas Airbus A380 engine failure in 2010 (2023)

#112
post #67

> the in-flight entertainment system, which featured a live view of the aircraft from a tail-mounted camera. The digital stream clearly showed a much more literal stream of fuel pouring from the left wing and into the aircraft’s wake, which was also visible with the naked eye from the lower deck. Johnson proceeded down to check for himself, at which point he also observed for the first time that there were two gaping…

Infamously, https://en.wikipedia.org/wiki/American_Airlines_Flight_191#A... This flight had a new system to allow passengers to see what the pilots saw. There's a chance that the passengers got to see the panic in the cockpit and watch their fates coming. I have seen claims that this caused such systems to be avoided for a while.

That's a nasty crash, but I feel like having one wing stall & the plane roll past 90° from below 500 ft AGL would be equally traumatic whether or not you could see the cockpit view.

Re: Qantas Airbus A380 engine failure in 2010 (2023)

#113

Earlier quoted context omitted.

That's disturbing. Ironically, the article in question was published July 4th last year. Note that the bar for defamation is a lot higher in the US than many other countries: https://en.wikipedia.org/wiki/Defamation#United_States

Not quite: https://en.wikipedia.org/wiki/Food_libel_laws

We're not talking about food.

Re: Qantas Airbus A380 engine failure in 2010 (2023)

#114

Earlier quoted context omitted.

It is worse than even that: > Within the space of four seconds, the energy from the annulus gas flow accelerated the IP turbine past its critical speed, until centrifugal forces exceeded the ultimate strength of the nickel alloy disk. The red-hot, wildly spinning disk instantly fractured into several sections, which rocketed outward in multiple directions at incomprehensible speed.

The fact that it's assumed to have infinite energy when planning for this is crazy. Engineers saying yeah there is no material in the world that can stop it.

Maybe not stop it, but perhaps they can design it so that if it happens it's more likely to be directed away from the fuselage? Like with armor that does not block or absorb but deflect, which requires less energy. Perhaps even a small reactive armor strip? (dangerous as though that would be on a plane).

But then again I'm sure aviation engineers would have thought of this and rejected it for good reason.

Re: Qantas Airbus A380 engine failure in 2010 (2023)

#115

I once heard someone describe Admiral Cloudberg's air crash investigation blog as "the best thing on the Internet" and I still think that might be true. She is a great researcher and a superb writer, which stands out all the more these days in these fallen times of load-bearing AI slop. Her blog is beloved of both aviation geeks and, for obvious reasons, SREs (and other engineers). She recently posted what's basicall…

I would also highly recommend checking out Mentour Pilot channel on youtube as she is the writer for some episodes. Accident videos there have interesting technical details.

I've watched some but I really hate watching videos. And I found that the videos she scripted basically follow the same flow as her corresponding article. So it felt like I'd already watched it.

If you like videos I'm sure they're great but if you love the writeup, you're not missing anything by skipping the videos IMO.

Ps I hate mentour pilot's clickbaity thumbnails so much. That alone puts me off from watching it too. But lately I use "DeArrow" which desensationalises all the thumbnails and even titles. That helps a lot. Mentour pilot is not alone in this, a lot of youtubers do it, but he sensationalises the severity of an aviation crash by going like "whoa kaboom!". Which is what I object to. Usually people died there and lots of them. It's strange because the actual videos have none of that.

Re: Qantas Airbus A380 engine failure in 2010 (2023)

#116

disc fragments didn't kill anyone just by accident. Have they not considered not seating anyone in the plane of the discs...

The problem is they can come out at up to a 30 degree angle so that would mean leaving out a lot of seats especially on a wide body quad-engined plane. Even on a narrow twin you'd already lose like 6 rows which makes it basically unviable.

Re: Qantas Airbus A380 engine failure in 2010 (2023)

#117
post #92

Earlier quoted context omitted.

You'd put the containment armor directly around the engine. It wouldn't take dozens of inches. Whether you use Newton's rule of thumb (penetration ends when the mass of armor displaced equals the mass of the shell that hit it) or more modern rules - a failing turbine disk is neither a precision-engineered anti-armor weapon, nor a heavy battleship shell. I'd bet the plane would still be able to take off, if it made it…

Full containment is probably possible, but it would render the aircraft nearly useless, not just economically uncompetitive. A 70kg chunk of nickel alloy is very dense, and at 800m/s , that’s 20 MJ. Thats about the same as 5kg of TNT, but focused on a small area. For comparison, a modern 120mm artillery shell fired from a tank or similar field artillery has 10-20 MJ of kinetic energy. A couple thousand kg of armour c…

Yes but on the warthog the discs are very far away from the pilot. Or pretty much anything else that matters. The fuselage can take a lot of a beating.

Re: Qantas Airbus A380 engine failure in 2010 (2023)

#118
post #92

Earlier quoted context omitted.

Full containment is probably possible, but it would render the aircraft nearly useless, not just economically uncompetitive. A 70kg chunk of nickel alloy is very dense, and at 800m/s , that’s 20 MJ. Thats about the same as 5kg of TNT, but focused on a small area. For comparison, a modern 120mm artillery shell fired from a tank or similar field artillery has 10-20 MJ of kinetic energy. A couple thousand kg of armour c…

Yes but on the warthog the discs are very far away from the pilot. Or pretty much anything else that matters. The fuselage can take a lot of a beating.

https://en.wikipedia.org/wiki/File:A10Thunderbolt2_990422-F-...

A failed disk from engine #1 is just a few feet from engine #2.

Re: Qantas Airbus A380 engine failure in 2010 (2023)

#119

disc fragments didn't kill anyone just by accident. Have they not considered not seating anyone in the plane of the discs...

The problem is they can come out at up to a 30 degree angle so that would mean leaving out a lot of seats especially on a wide body quad-engined plane. Even on a narrow twin you'd already lose like 6 rows which makes it basically unviable.

Ahh yeah. I thought they just go on one narrow plane...

Re: Qantas Airbus A380 engine failure in 2010 (2023)

#120

Earlier quoted context omitted.

Yes but on the warthog the discs are very far away from the pilot. Or pretty much anything else that matters. The fuselage can take a lot of a beating.

https://en.wikipedia.org/wiki/File:A10Thunderbolt2_990422-F-... A failed disk from engine #1 is just a few feet from engine #2.

That's a good point. Somehow I didn't think of that.
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