paulmooreparks 2 hours ago

I flew on this exact same plane, VH-OQA, on November 4, 2019, from Singapore to Melbourne.

While I was sitting at the gate, I remembered that line from Rain Main about "Qantas never crashed," and since that flight would be my first time flying on an A380, I wondered if any had crashed or had any other incidents. I looked up "a380 crash" on my phone, and what do you know? The first hit was a Wikipedia article about a Qantas A380 uncontained engine failure, which had occurred four minutes after takeoff... from Changi! Even wilder was the fact that it had happened 9 years earlier. When I looked up the plane's registration number on Flightradar24, I realized that was the same plane I was flying to Melbourne on.

  • gregjw an hour ago

    yikes, im sure that didnt freak you out at all.

u1hcw9nx 8 hours ago

Turbine disk failure is one thing that can down a plane, and you can only reduce the probability so much.

Fan blades and turbine blades can be contained by containment cases if they break off, but turbine disks can't. When a disk breaks, it's an uncontained engine failure. A 20 kg disk fragment flying at Mach 1 goes through everything.

Airframes are have a 30-degree fragment spread cone around every disk stage. Airframes are designed so that no single fragment can destroy all redundant systems at once in this zone (flight controls, fuel lines, and hydraulic systems). Jet fuel cannot be stored in the wings in this zone.

  • chasil 7 hours ago

    I admit that I glossed over the section on the machining of the oil pipe, but the facility appears to bear most of the blame.

    These were pulled and scrapped from the whole A380 fleet.

    "Investigators also criticized the culture within the Hucknall facility that manufactured the HP/IP bearing hubs, identifying signs of complacency and widespread procedural non-compliance. A paperwork review showed that the required signatures were missing from 131 out of 138 retrospective concessions issued between 2009 and 2011, and a large number of minor non-conformances had not been properly handled through the normal chain of command."

    • jacquesm 6 hours ago

      That's an oversight failure as much as a failure of that plant.

      • NetMageSCW 4 hours ago

        The oversight was at the plant.

        • jacquesm 2 hours ago

          Yes, but there are levels of oversight and this kind of thing should not be possible to hide. Someone on the official side of this messed up as well.

  • mcapodici 2 hours ago

    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.

    • mr_toad 18 minutes ago

      “It goes without saying that if any of the turbine fragments had entered the passenger cabin, there would have been injuries, if not fatalities, even if the plane later landed safely.”

      They got lucky.

  • usefulcat 6 hours ago

    > Jet fuel cannot be stored in the wings in this zone.

    TFA describes a fuel leak resulting from a piece of the turbine disk passing through a fuel tank located within the wing:

    "When the fragments of the IP turbine disk passed through the wing and belly of the A380, they caused considerable secondary damage along the way, not only to the №2 engine but also to the left wing fuel tank, which sprang a leak"

    It also includes a photo of the inside of the damaged wing tank.

    Was the requirement you describe added after this incident?

    • ahartmetz 5 hours ago

      Seems close to impossible for existing designs. The wings are commonly almost entirely full of fuel at max fuel, and I doubt that taking the capacity hit is an option even in newly designed planes.

  • amelius 6 hours ago

    But it seems to me that the whole failure could have been prevented with a bunch of temperature sensors spread throughout the engine, and a good anomaly detection system.

    • Farmadupe an hour ago

      Don't know why you're getting faded out, because having worked on exactly this engine, software mitigations were put in place. That's exactly your `anomaly detection system`

      It was a belt-and-braces fix, because the primary fix was of course to manufacture the engines correctly in the first place.

      The "lots of temperature sensors" thing is actually easier said than done; jet engines already have lots of temperature sensors, and they will turn the engine off if a huge overtemperature is detected, but it's not a free win to add more of them. It increases the risk of a faulty sensor shutting down a perfectly good engine in flight, which from a safety-critical perspective is a borderline disaster condition all by itself.

      (technically you usually cross-correlate temperature sensor readings with pressure sensor readings to prevent sensor faults turning engines off, but still, extra sensors isn't always a free win.)

  • polishdude20 7 hours ago

    What's a turbine disc?

    • gumby 7 hours ago

      It’s explained in the article

dostick 3 hours ago

The whole incident was because of 0.2mm offset in a machined part! And the company that made the part ignored the quality compliance process was not fired. I wonder why - did Airbus think it’s their failure not to verify that the subcontractor adhered to procedures?

  • quink an hour ago

    This feels more like engine manufacturer QC rather than anything Airbus.

    Because also, from Wikipedia: On 22 June 2011, Qantas announced that it had agreed to a compensation of AUD$95 million (£62 million/US$100 million) from Rolls-Royce. - skipping Airbus entirely.

CursedSilicon 7 hours ago

One of my favourite memories of flying Qantas when I was younger was the inflight entertainment.

If memory serves, they were celebrating some sort of milestone like "60 years without a fatal accident" or similar. Quite an impressive feat!

I'm unclear if it was directly related. But the Qantas inflight entertainment system on our flight from Sydney to Los Angeles meanwhile contained about 12 seasons of the National Geographic series "Air Crash Investigation" (Mayday: Air Disasters for Americans)

I will admit that show made an 18 hour slog of a flight significantly more enjoyable

  • AdamJacobMuller 2 hours ago

    Watching Mayday on flights is one of my favorite things to do for some odd reason.

  • alex1138 an hour ago

    That's hilarious. They don't think about "hey, maybe not show this, we might have nervous passengers"?

libraryofbabel 6 hours ago

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 basically her magnum opus, on the Potomac river midair collision.[0] It's the length of a short book. I'm working my way through it; I'm taking a flight today, and I'll probably read it on the plane tonight.

This article, on how an A380 with 469 souls aboard almost crashed, but didn't, is one of her best. I like it because it's a happy ending, and a story of the combined effects of good engineering design (the astonishing degree of redundancy built into the A380 proved just enough to prevent catastrophe), and human troubleshooting under pressure in the cockpit by some smart people with vast experience who remained calm throughout. (Another favorite article of her, on the Air France 447 crash, tells the exact opposite story: poor systems design combined with pilots basically losing the most basic ability to aviate in the heat of the moment. That one is a much darker read.[1])

[0] https://admiralcloudberg.medium.com/reaping-the-whirlwind-in... [1] https://admiralcloudberg.medium.com/the-long-way-down-the-cr...

exceptione 6 hours ago

  > The detailed software allowed them to enter various parameters including the weather, runway condition, and any systems failures, and then calculate whether it was possible to land. But when everything had been entered, the program spit out an unhelpful answer: “no result.”

 > When calculating the landing distance, the software applied a generic “operational coefficient” to account conservatively for variations in pilot techniques that could result in less efficient deceleration. The problem, as investigators would later discover, was that the software applied the coefficient again whenever another system failure was added. With so many system failures on the aircraft, the coefficient was applied a total of 9 times, resulting in a calculated landing distance considerably greater than the length of the available runway. However, Check Captain Evans was able to fix the problem by manually entering their actual landing weight, overriding the program’s assumption of a maximum landing weight. By specifying a landing weight in excess of the maximum, the system logic changed to apply the operational coefficient only once — for unrelated and obscure reasons — and lo and behold, when he ran the numbers this time, the computer said they could just barely land on any of the 4,000-meter runways at Singapore Changi Airport, with only 100 meters to spare.
This reeks so much of if-then-else programming as opposed to making a well-typed conceptual model computable.
NetMageSCW 4 hours ago

Retroactive, but one thing that struck me since they were overweight for landing and their fuel dump was inoperative, why not turn on the leveling pump and pump fuel out the hole in the left tank anyway? It would have lowered weight and improved balance.

  • vient 3 hours ago

    I got an impression from the text that pilots were not sure the fuel levelling line does not have a leak itself. Maybe they were afraid the line can leak fuel into fuselage somehow?

    • sleepy_keita 2 hours ago

      They got a warning that the fuel transfer system was damaged, so they decided not to use it, I think.

polishdude20 6 hours ago

I wonder why the engineers didn't specify a tolerance for thickness of the oil stub pipe?

  • okey 2 hours ago

    per the article, because the stub pipe counter bore had to be drilled after that end of the pipe was welded in place, so directly measuring pipe wall thickness wasn't practical

  • NetMageSCW 4 hours ago

    Difficulty in measuring since it was machined after installation?

realo 7 hours ago

Catastrophic failure? Check

Plane landed without casualties? Check

Plane design so good it helped avoid casualties? Check

Hum... Ah! Not an american Boeing but a french Airbus. Of course.

The article mentions this story should make everyone a little less afraid of flying.

Sure, as long as its not on a Boeing plane.

  • jpgvm 3 hours ago

    The plane was a significant factor but you really shouldn't look past the calibre of expertise in the cabin on this particular flight.

    > 5 pilots were in the cockpit of this flight. In addition to the normal crew of pilot-in-command and co-pilot, there was an experienced relief pilot and two additional check captains; one was being trained as a check captain (CC) and the supervising CC, who was training the CC.

    Captain Richard Champion de Crespigny had 35 years of flying experience at the time of the incident.

    That is an insane amount of flight experience in the cockpit and all of the reports state this was a very significant factor. i.e by allowing distribution of the task load, plenty of time for one of the pilots to compute landing calculations manually etc.

    THe A380 is a flying tank no doubt, but it wasn't the sole factor here - I think most people would agree this one was a shared victory.

  • sam1714 6 hours ago

    Like Boeing, there was organizational dysfunction leading to a direct safety issue.

    During the development of the A380, the German and French sides were using different versions of the CATIA PLM software (i.e. CAD), which prevented people from looking at a single unified model of the plane. One concrete problem it caused was major problems with the wiring harnesses, which led to a 2 year delay in the program, and 3 early A380's which couldn't be sold. (Airbus kept one for test, the other two got sent to museums)

    That manifested in this accident because the wing wiring was routed through the engine disk burst axes (a hazard which is explicitly accounted for) with insufficient redundancy. That created the dangerous situation where they couldn't turn off the engine after landing.

    • jacquesm 6 hours ago

      > That created the dangerous situation where they couldn't turn off the engine after landing.

      Which is vastly preferable compared to all of the dangerous situations just prior to that landing.

      • sam1714 6 hours ago

        The vastly preferable situation was to have redundant wiring that properly complied with regulations, which was retrofitted in an airworthiness directive (safety recall) after the accident.

        They also required engine software that detected the sudden increase in speed associated with a shaft break and automatically cut fuel.

  • renox 6 hours ago

    Read about the AF447 Rio-Paris crash. Input stick averaging?? That's a huge design mistake which contributed to the crash and AFAIK is still here..

    • echoangle 5 hours ago

      What’s the alternative? I think averaging with a dual input alert is a pretty good solution. Otherwise you need to find a solution to transition from one stick to the other. You can’t just switch sticks with the press of a button because the input could jump from elevator up directly to elevator down for example.

      • 4fterd4rk 4 hours ago

        You give them direct feedback and eliminate the need for this completely

  • ginko 6 hours ago

    Airbus is French, German and British. Not just French.

    • bluebarbet 4 hours ago

      The state-held stakes are mainly French, German and (less) Spanish. The UK taxpayer currently owns 0% of Airbus, though the UK gets the business of building wings and landing gear.

  • seizethecheese 6 hours ago

    I thought this was a strange insertion of geopolitics into the conversation so I checked out this account’s comment history. It’s good for others to see that some commenters here have a serious axe to grind and are not really “hackers” as their primary interest here. The most recent comments in order:

    > [something about london taxi drivers, admittedly unrelated]

    > I totally get you and in theory you are right. And yet, in the USA you have gerrymandering and apparently _wanted_ Trump. Twice. Something has to be very wrong somewhere.

    > I would suggest "lobbying" is not the correct word to describe all the corruption going on in the current USA administration cesspool.

    >I recently bought a BambuLab 3D printer. Designed and made in China. Right from the unpacking to first print the experience was top Apple-style quality. Indeed I was agreeably surprised.

    > A global non USA success? Plenty. You might want to remove your pink USA glasses and look around. Spotify good enough for you?

    > I am Canadian. Never, ever would i knowingly buy any dairy products from the USA , at any price. We have cows too, and farmers.

    > Its not that it hates its customers , as much as it it a USA-based company that is run under the rules made by the administration. Not that much different from running Red Star OS from North Korea, actually.

    > [Finally something unrelated]

adaml_623 6 hours ago

"Even the airplane itself ultimately survived: after a marathon repair that lasted 535 days and cost $139 million, the A380 Nancy-Bird Walton triumphantly returned to the skies in 2012."

This quote amazes me. My understanding is that Airbus, Qantas, and probably Rolls Royce were willing to spend this much because it meant that the incident was not a "hull loss" and therefore not as bad a hit to reputation and safety statistics. Does anyone know if that's true?

  • ygouzerh 23 minutes ago

    One thing that might be taken into account is the delay between ordering a plane, and the delivery (can take up to 10 years), so 1.5 years and 139$ million is worth investing into, to keep revenue flowing earlier.

  • ahartmetz 5 hours ago

    A new A380 is more expensive (rule of thumb half of official list price, so about $220 million), and airlines were not talking about retiring A380s yet at the time. So it even made economic sense.

    • stephen_g 3 hours ago

      The plane has since had a cabin upgrade and is still expected to operate at least until 2028. It’s operating SIN-LHR right now as I write this, currently flying over Azerbaijan.

  • shawabawa3 5 hours ago

    They paid an estimated $300M per aircraft, so even a $139M repair bill is worth it

Alien1Being 7 hours ago

Qantas is a troubled airline. Once a Qantas aircraft technician even told me that Singapore Airlines have a far superior maintenance schedule for their aircraft.

This person claims that he tells his family to avoid flying on Qantas ( but flies on it himself since he gets free flights)

These days Han airlines ( SIA, Cathay,China Eastern) and Middle Eastern airlines (Emirates,Qatar) are far better than Western Airlines ( American, British, Lufthansa, KLM,Qantas).

  • tomhow 7 hours ago

    Please don’t post off-topic hearsay like this here. This article isn’t about maintenance, it’s about a manufacturing fault and the incredible work by the pilots to avert a colossal aviation disaster. Qantas continues to have an unblemished record of safety. Running airlines cost-effectively is a continually growing challenge. There is always a place for scrutiny of airlines’ maintenance and safety practices, but introducing it out of context and based entirely on an unverifiable comment from an unidentified individual is not a helpful contribution to this discussion.

  • HDBaseT 5 hours ago

    Despite this, Qantas is consistently rated one of the top 3 safest airlines in the world every year.