back to article Airbus issues patch to prevent A350 airliner fuel tanks exploding

Airbus has issued an emergency patch to stop its A350 airliners from exploding. The fix, an update to the aircraft's Master Minimum Equipment List (MMEL), adds a number of items to in-cockpit displays to prohibit affected airliners from flying. "Recently, an overheat failure mode of the the A350 hydraulic Engine Driven Pump ( …

  1. samzeman

    Good that it's fixed, but also terrifying. This is why I try not to use planes (or lifts or escalators)

    1. I ain't Spartacus Gold badge

      Not sure I'd call it terrifying, since I don't think it's actually ever happened.

      Maybe this came from a near-miss, where some of the circumstances occurred to risk it happening, and disaster was averted. Or maybe it came up in a periodic safety review.

      But the reason that flying is safer than almost any other form of transport is that aviation generally learns from its near-misses, as well as its disasters.

      I heard an interview with a pilot who said that he sometimes has to report a couple of incidents a month to regulators. I don't know if that's because he's particularly conscientious or it's normal. But mostly these are minor incidents that they can log, and if something is happening a lot, then they can look at changing procedures in order to correct the issue.

    2. Anonymous Coward
      Anonymous Coward

      Do you drive a car?

      You know, that activity where any of many of hundreds of peoples' minor cockups could end your life in a matter of seconds on any given day? Ever fall down the stairs? I assure you, you take greater risks on a daily (perhaps even hourly) basis than flying or taking a lift/escalator. This is intended less as snark, and more as... don't let yourself not enjoy life over nonsense like this.

      1. samzeman

        Re: Do you drive a car?

        I don't drive except in emergencies, it's bad for the environment. I cycle or use public transport. I realise there are bigger risks I take all the time, but I can't do anything about them, and they're not necessarily as severe. For example, escalators have a low risk (except at peak hours or in china, but even still) but the severity of being ground up by the internals? I'm terrified. It's irrational, I know, I have something like traumataphobia. But I can avoid that. Travelling is necessary, living in the possible path of yellowstone, gamma ray bursts, meteorites is necessary.

        I try to get over it. I just don't feel right on an escalator is all. Also, blah blah environment.

        1. druck Silver badge
          Stop

          Re: Do you drive a car?

          @samzeman: "I don't drive except in emergencies"

          Exactly the conditions you shouldn't be driving; you lack the experience of regular driving, and you are under additional stress. If only a software patch would keep you off the road in such circumstances.

        2. DropBear Silver badge

          Re: Do you drive a car?

          You're actually arguing against yourself - if you cycle, you actually take on orders of magnitude more risk than even driving a car, never mind how much more hazardous cars are compared to flight...

          1. Anonymous Coward
            Anonymous Coward

            Re: Do you drive a car?

            At the very least, his contribution to a major accident would be minimal... very little chance of a cyclist causing collateral damage when hit. Also, perhaps even more so on a bike, (provided you have good situational awareness), you have more direct control over what you're doing/where you're going than just about any other form of transportation.

            1. Rameses Niblick the Third Kerplunk Kerplunk Whoops Where's My Thribble? Silver badge

              Re: Do you drive a car?

              "At the very least, his contribution to a major accident would be minimal..."

              Whilst what you say is true to a certain degree, it's not *entirely* accurate, as shown here:

              http://www.bbc.co.uk/news/uk-england-41028321

              You are massively more exposed on a bicycle in traffic than you are in a car, any injuries you sustain from any minor accident will be significantly worse than those of the driver of the car / van / truck which hits you.

              Versus pedestrians however, seems cyclists do still have an edge.

          2. Stuart 22

            Re: Do you drive a car?

            "You're actually arguing against yourself - if you cycle, you actually take on orders of magnitude more risk than even driving a car,"

            Actually its the same order of risk as a pedestrian. The car stats are distorted because they are usually done by miles rather than time (as are flying stats). And, of course, if you drive a car you are a considerable risk to cyclists and pedestrians. So not getting behind a wheel reduces the risk to all other road users.

            Its the good thing to do. It also reduces the probably larger risk of killing/shortening lives by pumping out pollution. And, of course the exercise you get walking/cycling enhances life expectancy rather more than any increased risk of being killed in a collision.

            Pretending that using a car makes the planet safer or your life longer is an illusion I'm afraid.

            1. SkippyBing Silver badge

              Re: Do you drive a car?

              'It also reduces the probably larger risk of killing/shortening lives by pumping out pollution.'

              I have seen an alternative take on this, although I haven't had a chance to verify the numbers. Essentially fuel is a very efficient method of storing and transferring energy, whereas food isn't. Also food production and transportation takes a not insignificant amount of energy, which involves producing pollution. Consequently it is possible for a cyclist to be responsible for more pollution than a driver, it's just not in the immediate local area.

              It was on one of a series of youtube videos called 'Adam Ruins X' which seem to have been at least moderately well researched, but as I say I haven't run the numbers myself so I'm not sure how valid the argument is, e.g. does it just apply when comparing a mad keen cyclist with someone who drives 1/4 mile work.

              1. Allan George Dyer Silver badge
                Coat

                Re: Do you drive a car?

                @SkippyBing - Unless you think that cars are driven by zombies, you should only include the extra food consumed to fuel the transportation running/cycling.

                1. SkippyBing Silver badge

                  Re: Do you drive a car?

                  'Unless you think that cars are driven by zombies, you should only include the extra food consumed to fuel the transportation running/cycling.'

                  I believe that was taken into account but the delta should be quite large. A quick google shows 29 calories for a 15 minute drive, which is how long it takes me to drive the ~8 miles to my nearest place of work. Running that takes me about an hour, but on the conservative side that's 800 calories. Cycling would appear to be around 300 calories from another quick google. So you're looking at about a 10 times greater calorie burn cycling vs driving and 27 times for running.

                  The sources the programme used are here: http://www.trutv.com/shows/adam-ruins-everything/blog/adams-sources/adam-ruins-going-green.html

                  I suspect they're considering someone with a omnivore lifestyle as meat production consumes a lot of energy. Vegetarians can probably be smug about their food's energy consumption. But they don't get to eat bacon so their loss.

                  Just to be clear I'm not saying I buy the argument but I suspect it's more closely balanced than people may think.

            2. Anonymous Coward
              Anonymous Coward

              Re: Do you drive a car?

              " And, of course, if you drive a car you are a considerable risk to cyclists and pedestrians. "

              Only if you look it from statistics as they don't show anything else but the amount of killed/injured.

              Here in North we had 7 dead pedestrians last year (out of 450k people in town) and out of those 7, 6 basically killed themselves by running against red light to the traffic or things like that. Actual cause of death: Stupidity.

              The last one was the only one where the pedestrian was actually obeying the traffic rules and thus innocent. Of course the numbers are very small but it's not a sample, it's all cases and therefore statistically significant.

              I have a hunch that the situation isn't different anywhere else, either. Pedestrians everywhere are very bad at obeying traffic rules and that causes 'accidents'.

              So the biggest risk to pedestrians aren't cars, but pedestrians themselves.

              Unpopular truth which is never said as it's not politically palatable and definitely isn't visible in any standard statistics, they aren't made that way: The idea is to make car owners guilty to anything that happens regardless of actually being guilty.

              That is intentional politics, it doesn't just happen.

              1. not.known@this.address Bronze badge
                Holmes

                Re: Do you drive a car?

                Someone asked the local council in Farnborough where they got their accident figures and they said from Hampshire police, so they asked Hampshire police where they got their accident figures from and they said...

                "The Council".

                This was after a road was classified as an accident blackspot "after a number of fatalities" - which was strange as it was one of the most accident-free parts of town! Surprisingly since it was between the shops near FAST and the roundabout near the Aerospace Center, where cars often pull out without really looking, there had only been one fatality in the ten years I lived there - and that was a drunk who stepped out from between parked cars at night, and the driver had no chance to see him let alone try to avoid him.

                It was also around the time that various police forces were found to be counting each car involved in any incidents as individual "hits" in the statistics - so if a lout walked down the road keying a dozen cars, that would be a dozen car 'accidents' even if the owners/drivers were tucked up in bed asleep when it happened!

                Lies, Damn lies, and Statistics.

        3. Anonymous Coward
          Anonymous Coward

          Re: Do you drive a car?

          Your viewpoints/concerns on the matter are grounded in reality, which is better than I get back out of most people. So long as you're able to live a fulfilling life, there's nothing wrong with any of that. No two humans see things exactly the same.

        4. CrazyOldCatMan Silver badge

          Re: Do you drive a car?

          I don't drive except in emergencies

          Just as well you don't have a job that requires you to drive then..

          1. Craig 2
            Trollface

            Re: Do you drive a car?

            "Just as well you don't have a job that requires you to drive then.."

            He could be an emergency ambulance driver and his original statement would still be true...

      2. Archtech Silver badge

        Re: Do you drive a car?

        "... don't let yourself not enjoy life over nonsense like this".

        I'm sure your advice is well-meant, but such issues are really a private matter between each person's forebrain and his/her amygdala.

  2. Field Commander A9

    Hmm, so this patch cannot be applied over-the-air?

    1. choleric

      The fix, as described: a simple change to a list, could be delivered OTA, but for the undoubtedly stupefying amount of paperwork involved. Replacing the suspect components on the other hand... that's a hardware issue!

      Happy to report my recent flight on board an SIA A350 went without observable hitch, let alone thermal runaway failure modes. I was keeping an eye on the carbon fibre reinforced wings - my kids were more impressed with the touchscreen media systems. Lovely plane.

      1. ElReg!comments!Pierre Silver badge

        Re: Lovely plane

        It is a pretty cool bird indeed. The looks alone...

    2. A Non e-mouse Silver badge
      Coat

      Why not? It's an emergency hot fix....

    3. Anonymous Coward
      Anonymous Coward

      The should have got them in for the Note 7.

      1. Voyna i Mor Silver badge

        "The should have got them in for the Note 7."

        If the Note 7 had had a cooling system in its fuel tank (the battery) perhaps the recall wouldn't have been necessary. [Yes, yes, I know that isn't actually what happened].

    4. JJKing Bronze badge
      Coat

      Patching french rubbish.

      Hmm, so this patch cannot be applied over-the-air?

      If they did apply the patch over the air, the aircraft would have to land and take-off again before it was updated.

      Mine's the BCOD (Blue Coat Of Death).

  3. Anonymous Coward
    Anonymous Coward

    Stop <> prevent

    "Airbus has issued an emergency patch to stop its A350 airliners from exploding."

    This suggests that A350s are exploding, which they're not. The emergency patch will prevent A350 airliners from exploding.

    1. Anonymous Coward
      Anonymous Coward

      Re: Stop <> prevent

      Maybe not. They may explode for another reason.

      1. Robert Carnegie Silver badge
        Mushroom

        "discourage airliners from exploding"

        Anyway, reading carefully, it is only the fuel tank that explodes. :-)

    2. Milton Silver badge

      Re: Stop <> prevent

      There's much to like about El Reg but the clickbait stupidity of its headline writers is definitely not on the list. The entire publication would be lifted into the next league—where arguably it belongs—if it would simply stop the clumsy, infantile puns (they are rarely clever and never funny) and most especially do NOT print deliberately misleading headlines about important topics. The next time a manufacturer issues a software upgrade to its planes' terrain detection systems, will you feel comfortable with a headline screaming: "Boeing fixes code to stop its aircraft piling into mountainsides"?

      I daresay the publishers may still envision their audience as spotty nerds who cannot talk to girls and guffaw like third-formers at silly jokes—but the truth is those guys grew up many years ago and now it's the Reg that looks foolish. Time to pack away your juvenile keyboards.

      1. Anonymous Coward
        Anonymous Coward

        Re: Stop <> prevent

        FFS, I come here for the puns.

        I work more hours that I care to think about with people who are more concerned about being seen as "professionals" than solving problems, so I greatly appreciate a site that continues to poke fun at events, yet does a good job to then dig deep after the headline.

        I thus disagree. Puns are just as much part of it as good journalism.

      2. Robert Helpmann?? Silver badge
        Flame

        Re: Stop <> prevent

        The entire publication would be lifted into the next league—where arguably it belongs—if it would simply stop the clumsy, infantile puns...

        I read the stories precisely because of the puns. DO NOT CHANGE!

        There. In much the same way reporting should be fair and balanced, so too should comments.

      3. gazthejourno (Written by Reg staff)

        Re: Re: Stop <> prevent

        Given that the original EASA safety directive (go and find it, it won't take you long) specifically references the risk of explosion, as I quoted in the article, I have no idea where you've got this false notion that mentioning the identified risk is clickbait. Unless, of course, you read the headline alone and immediately leapt into the comments section to show off how 'superior' you believe yourself to be.

        If, say, Boeing issued an update to prevent an identified risk of CFIT with the autopilot engaged, then yes, I would very happily write "Boeing fixes code to stop its aircraft piling into mountain sides". Because that's what would be happening there.

        1. Anonymous Coward
          Anonymous Coward

          Re: Stop <> prevent

          @gazthejourno: "Boeing fixes code to stop prevent its aircraft piling into mountain sides"

          FTFY

          1. DropBear Silver badge
            Headmaster

            Re: Stop <> prevent

            Actually, "stop" immediately "grated on my ears" as well as soon as I read it. The implication that they would be otherwise exploding left right and centre is just too strong, even if it's a somewhat subjective interpretation. What isn't already moving doesn't need to be stopped after all. And frankly, "prevent" isn't much better - it carries much the same connotation of altering the course of something that was already going to happen. I'd personally prefer something along the lines of "Airbus eliminates fuel tank explosion risk factor" but I do concede it isn't as snappy a title, all this largely being splitting hairs anyway...

            1. Borg.King

              Re: Stop <> prevent

              "Airbus eliminates fuel tank explosion risk factor"

              "Airbus reduces fuel tank explosion risk factor"

              ftfy.

            2. Anonymous Coward
              Anonymous Coward

              Re: Stop <> prevent

              @DropBear: In the context of the article stop can't apply to something that hasn't started because there is nothing, as yet, to be stopped. Prevent can only be applied before something has started because if you try to apply prevent to something that has already started then it was not prevented.

              I agree that prevent isn't ideal though, because it's comprehensive and implies that the outcome can never happen even though only one of many potential causes has been addressed - it really needs the addition of the clause 'for this particular reason'.

              I don't think eliminate really gets us anywhere better.

              I also don't think it's just splitting hairs either - there was fundamental difference between what was meant and what was actually said.

        2. Scroticus Canis Silver badge
          Meh

          Re: Stop <> prevent - where's the "possibly"?

          This "fix" only stops the plane from taking off if the fault is present before flight. Way I read it if the specified fault develops during flight then a fireball in the sky is still all to possible; like a Boeing with the lithium batteries mounted in the fuel tank.

        3. Craig 2

          Re: Stop <> prevent

          You can't stop something unless it has started...

          They have not started exploding.... QED

  4. Anonymous South African Coward Silver badge

    An aeroplane is a massive collection of spare parts all travelling into the same direction at the same time.

    1. Anonymous Coward
      Anonymous Coward

      So they’ve moved on from rivets? [YouTube]

    2. Mark 85 Silver badge

      The corollary for helicopters (from my military days): "A collection parts flying in loose formation in the mostly same direction, at the same time."

      1. Aladdin Sane Silver badge

        I was always told that an aircraft is a massive collection of lowest bid contractor parts flying in loose formation.

    3. CrazyOldCatMan Silver badge

      An aeroplane is a massive collection of spare parts all..

      ..supplied by the lowest-cost bidder.

      Or is that only NASA spacecraft?

  5. Pen-y-gors Silver badge

    I Am Not An Aeronautical Engineer

    But, to the casual observer on the Clapham Omnibus, it would perhaps be thought that the best, and only, thing to put in a fuel tank is fuel (and inert gas)? Obviously there must be reasons why it's felt to be a good thing.

    1. maffski

      Re: I Am Not An Aeronautical Engineer

      It's a convenient way of dealing with the heat in the hydraulic fluid - transfer it to the fuel and then burn the fuel and throw it out of the back of the engine. Makes the engine (very slightly) more efficient and saves the drag of an extra cooling system for the hydraulics.

      1. PerlyKing

        Re: I Am Not An Aeronautical Engineer

        Wasn't there a problem a few years ago which was thought to be due to ice crystals forming in the fuel? Cooling the hydraulics and warming the fuel (a little) sounds like win + win. As long as it doesn't go too far....

        1. SkippyBing Silver badge

          Re: I Am Not An Aeronautical Engineer

          Wasn't there a problem a few years ago which was thought to be due to ice crystals forming in the fuel?

          That was the BA 777 that 'landed*' just short of the runway at Heathrow, I think the issue was the crystals forming/collecting at the point where fuel left the tank for the engine while they were essentially at idle during the descent to land. They'd taken a long route over Siberia through an exceptionally cold layer of air which led to the fuel being cooled beyond the assumptions made in designing the system, as I understand it.

          *It was undoubtedly a much better landing than I would have achieved in the circumstances.

          1. Jon 37
            Boffin

            Re: I Am Not An Aeronautical Engineer

            The BA 777 issue was that as they cruised at cold, high altitudes for a long time, ice crystals collected on the walls of the fuel pipes. Then they had a nice gentle descent that allowed the ice to stay there. When they increased the throttle just before landing, the suddenly increased fuel flow dislodged all the crystals and they all collected at the entrance to the fuel oil heat exchanger. That reduced the fuel flow, so they didn't have enough power to reach the runway. Thanks to some quick thinking by the pilots, they managed to avoid the residential area and landed short in the grass just inside the airport boundary fence, with the hard landing pushing the landing gear through the wings.

            Ironically, the fuel oil heat exchanger is intended to warm up the fuel and ensure there's no ice in the fuel to cause problems later in the engine. It consists of a series of metal plates with the hot engine coolant flowing over one side of each plate and the fuel flowing over the other. They crash investigators discovered that the end the fuel came in, there was a small amount of sticking-out metal that could be cold enough that the ice there wouldn't melt. They fixed it by grinding it flat, so if any ice gets stuck there it will get hot and melt straight away.

            (Disclaimer: I Am Not An Aeronautical Engineer either, but I like air crash investigation TV shows and I saw one about this crash...)

          2. Anonymous Coward
            Anonymous Coward

            Re: I Am Not An Aeronautical Engineer

            @SkippyBing: Summary & link to report (pdf):

            https://www.gov.uk/aaib-reports/1-2010-boeing-777-236er-g-ymmm-17-january-2008

        2. Steve Davies 3 Silver badge

          Re: Fuel freezing

          If I remember correctly that was the reason that the BA 777 was crash landed/belly flopped at Heathrow.

      2. SkippyBing Silver badge

        Re: I Am Not An Aeronautical Engineer

        It also helps prevent icing in the fuel, although I think that's mainly the job of the fuel/oil heat exchanger.

      3. Anonymous Coward
        Anonymous Coward

        Re: I Am Not An Aeronautical Engineer

        "Makes the engine (very slightly) more efficient "

        It's been years since Thermodynamics I, but I would suspect hotter fuel makes the engine slightly *less* efficient.

        Granted, on a systems level, dealing with the heat in this manner is probably the most efficient way to deal with it, but that may have more to do with economic concerns, payload capacity, safety, etc...

        1. Steve the Cynic Silver badge

          Re: I Am Not An Aeronautical Engineer

          "It's been years since Thermodynamics I, but I would suspect hotter fuel makes the engine slightly *less* efficient."

          It's *more* efficient because it isn't necessary to heat the fuel quite as much. The energy to do that for a bit of fuel comes, crudely speaking, from the combustion of the previous bit of fuel, and therefore it is not usable as output work for the engine. If that next bit of fuel isn't quite as cold, you don't spend as much energy heating it, and therefore you can squeeze a tiny amount more useful work out of that bit of fuel.

          And a a bonus, the fuel won't be quite as close to dangerous temperatures like "the traces of water in this fuel are trying to freeze and clog up the fuel pumps with ice crystals".

        2. DJO Silver badge

          Re: I Am Not An Aeronautical Engineer

          For the archetypical Carnot heat engine lowering the temperature differential between the fuel and the engine body does lower the engine efficiency but modern jet engines are slightly more complex beasts than a simple heat engine.

          1. Steve the Cynic Silver badge

            Re: I Am Not An Aeronautical Engineer

            I thought that was for the temperature of the *combusted* fuel and the environment.

            (Reads a little on the Unreliable Source.)

            Yes, it is. There's a hot bit (combusted fuel) and a cold bit (the engine and the environment around it), and the efficiency is limited by the ratio of the absolute temperatures. Specifically, the efficiency is limited to less than 1 - Tcold/Thot.

            So raising the temperature of the incoming not-yet-combusted fuel will allow the engine to spend less energy heating it to ignition temperatures, and thus raise the temperature of the combusted gas slightly, in turn lowering Tcold/Thot and thereby raising the limiting efficiency.

    2. jonathan keith

      Re: I Am Not An Aeronautical Engineer

      Obviously Airbus have customised their A350 fleet with some sweet liquid cooling. Now they just need to add some clear panels and tasteful LED lighting to the wings to properly show off their pimped rigs.

    3. Voyna i Mor Silver badge

      Re: I Am Not An Aeronautical Engineer

      "Obviously there must be reasons why it's felt to be a good thing."

      You don't even need to be an aeronautical engineer. Using fuel to cool things has been around for a long time. Some cars with carburettors had fuel systems that cycled fuel round the carb to reduce the temperature, and the last boat Diesel engine I installed had continuous fuel circulation around the on-engine header tank to keep the fuel reaching the actual fuel pumps from getting hot. A big tank of liquid which is in contact via thin walls with the atmosphere or water is a very good heat sink.

    4. The_H

      Re: I Am Not An Aeronautical Engineer

      All manner of stuff is cooled / heated using fuel and oil. Seem to remember the good old Saturn V ran the liquid oxygen / kerosene through tubes around the outside of the F1 engine bell to keep it cool too.

      You'd be surprised just how much gear you'd find in an airplane fuel tank!

  6. Anonymous Coward
    Anonymous Coward

    Welcome aboard..

    ...this Airbus A350

    probably NOT the words that I want to now hear. Should I feel safer if a see an A320 welcome card though? At least they now know about this issue (however, what happens now if the fault occurs mid-flight??)

    1. Voland's right hand Silver badge

      Re: Welcome aboard..

      Should I feel safer if a see an A320 welcome card though?

      No. Many airlines override this manually. All it takes is an airbus engineer to sign it off.

      I have seen this happening on one well known UK airline more than once (I had to wait for 2h on one occasion until they found one as it was national holiday at the airport I was flying out of).

      1. SkippyBing Silver badge

        Re: Welcome aboard..

        'No. Many airlines override this manually. All it takes is an airbus engineer to sign it off.'

        I'm not sure I follow you, I don't think anyone can over ride the MMEL, an airline might decide to over ride it's own MEL as that's more restrictive than the MMEL.

  7. J J Carter Silver badge
    Pirate

    No thanks!

    After being burned by Windows 10 updates, I won't be taking these patches!

    1. Steve Davies 3 Silver badge

      Re: No thanks!

      These patches may well have had a few orders of magnitude more testing before release than MS ones.

      We shall have to wait to see if any A350's BSOD in the next few months for confirmation of that.

      1. RPF

        Re: No thanks!

        As with most things in aviation, these issues were "identified" only after people died....in a Boeing 747.

        https://www.ntsb.gov/investigations/AccidentReports/Pages/AAR0003.aspx

        Not A350-specific, at all. I would argue that they've just made the A350 even safer than ever.

      2. CrazyOldCatMan Silver badge

        Re: No thanks!

        These patches may well have had a few orders of magnitude more testing before release than MS ones.

        Any positive integer is > 0..

  8. ottocom

    Brilliant!

    I wonder why there are not so many people to react to the fact that placing a "cooling system" in a gas tank is completely stupid...

    Though Jet A! and derivative are heavy fuels and don't ignite with a simple spark, heating them reduce the amount of energy needed to trigger a fire and vapors... are vapors and can ignite with a spark.

    So, why just a software patch and not a hardware fix for such problem? Are they waiting for one to explode in flight? Because, the fact that you know your systems are working at take-off doesn't mean that the problem would not occur in-flight and what will you do while flying above the ocean?

    1. SkippyBing Silver badge

      Re: Brilliant!

      'I wonder why there are not so many people to react to the fact that placing a "cooling system" in a gas tank is completely stupid...'

      So completely stupid that most major airliners use exactly the same system and have done for decades. Not to mention using the fuel to cool the engine oil.

      Some Russian fighters even use fuel as the hydraulic fluid to actuate the engine nozzle, although that's not strictly relevant to airliners.

    2. ElReg!comments!Pierre Silver badge

      Re: Brilliant!

      Fuel is very efficient in a cooling system, as the PFY could tell you.

      https://www.theregister.co.uk/2002/05/11/bofh_and_the_vax_cluster/

    3. Thoguht Silver badge

      Re: Brilliant!

      The SR-71 Blackbird actually used its fuel as a coolant for the airframe leading edges and the avionics.

    4. DJO Silver badge

      Re: Brilliant!

      vapors and can ignite with a spark.

      ½ correct ½ wrong

      Vapours can ignite with a spark in the presence of Oxygen

      Now engage your remaining brain cell and consider if the manufacturers might have thought about purging the tanks with nitrogen (or some other gas, CO2 would do the job I suppose)?

  9. Milton Silver badge

    Heat exchangers are not unusual

    The Reg audience is better placed than most to know that non-trivial high-energy systems have all sorts of cooling issues.

    You have hot hydraulic fluid *here*; nice cold fuel *there*. It's necessary to cool the hydraulic fluid and it's also useful to warm up the fuel. So you have a heat exchanger.

    You have very hot lubricating oil flowing through *these* pipes, making sure your turbines rotate smoothly and frictionlessly; you've got JetA1 that's been lurking in wing tanks by the tonne while you dawdled across the Pole at 39,000 feet. One needs to be cooled, the other kept above a certain temperature. Yep, heat exchanger.

    (Some gas turbines benefit from using hot exhaust air to pre-warm the incoming compressing stream before it reaches the ignition cans, even: adds to efficiency—not sure if any aero engines do this though.)

    You have hundreds of kilos of lovely cold dense air being sucked in through the fan; and you've got a high pressure turbine in the core running at about 300° hotter than its melting point, so you bleed some of that cold air through the hollow insides of the HP blades onto their surfaces to stop them melting. Heat exch—, ok, sorry, you get the picture.

    Fuel tank inerting was mandated after TWA800 blew up some years back, because a combination of unfortunate circumstances occurred: it's almost always the way with plane crashes: several nasty coincidences, never just one thing—too long on the ground on a hot day before takeoff with the aircon running at full tilt; aircon packs right below the centre fuel tank, cooking it up; tank nearly empty because the fuel wasn't needed for this journey, creating a large vapour space; dodgy insulation on a fill sensor; and a short circuit which dumped more volts onto that sensor than it was supposed to have. Any one of those things NOT happening: no crash. Even the sensor was wired for very low voltage in normal operation, too low to cause an ignition spark. You needed the truly cruel fate of a higher-voltage short to finish the job.

    My point being that well-engineered heat exchange mechanisms are generally very safe and vitally useful. Even the BA38 coming down short at LHR was a combination of bad luck coupled with a small and arguably unforeseeable design flaw (in this case, unusually long period of flight at unusually low temperatures, and a fuel-oil heat exchanger form factor which allowed water ice crystals to be captured and build up in a Bad Place, restricting fuel flow).

    So, with apologies for the lecture, my point is that Airbus' mods in this case may be an excellent example of why air travel is so safe: a lesson has been learned and an abundance of precautionary action is being taken, because you never know when that bastard Murphy may strike next. Note well, too, that the lesson learned from a Boeing is being applied to an Airbus: personally, as someone who remembers the bad old days of DC-10 cargo doors, I am greatly reassured that where engineering safety is concerned, there is no fanboi-pissing-around, just a solid and creditable determination to keep the self loading cargo alive.

  10. Dave 32
    Coat

    In-tank Fuel Pumps

    According to a long-time auto mechanic friend, most (all) automobiles with in-tank fuel pumps (which are a majority of them now?) depend upon the fuel cooling the pump. Thus, you get much longer fuel pump life if you refill the fuel tank when you're down to about a quarter of a tank, rather than allowing it to get lower.

    Oh, and remember that gasoline is MUCH more flammable than jet fuel.

    Dave

    P.S. I'll get my coat; it's the one with the spare can of gasoline in the pocket.

  11. John Smith 19 Gold badge
    Unhappy

    I never tire at the number of ways airlines and airline mfg find to create fuel air explosives

    Or (as some meja outlets have called them) the "Poor man's atomic bomb."

    IBack in the day there were a couple of really impressive explosions when the Captain rain the planes aircon on the ground during an extend hold at a gate.

    Their aircon pack was under a "nearly" empty fuel tank. Aircon got hot, fuel vaporised. No inerting system. Boom. In fact I think that was one (of several) bangs that made fuel inerting systems mandatory on big aircraft.

    But "Take off without a working inerting system?" WTF ?

    That said if this has never caused a bang that makes it a potential hazard, not one actually seen.

    Which would seem to be an improvement.

  12. Anonymous Coward
    Anonymous Coward

    That's what they get

    For using Samsung parts in it!

  13. Sureo

    "The A350's hydraulic fluid cooling system is located inside its fuel tanks. "

    So how does it work when the tank is empty?

    Must be a bitch getting in there to fix a part.

    1. SkippyBing Silver badge

      Re: "The A350's hydraulic fluid cooling system is located inside its fuel tanks. "

      On at least one occasion someone left a chair in a 747 fuel tank, so getting in the to fix things isn't usually a problem.

      Most (all?) aircraft have an an unusable amount of fuel, the heat exchangers will be covered by that. Not forgetting they'll normally be landing with reserves for diversions etc. So it's rare to land with less than a few tons of heatsink.

  14. Anonymous Coward
    Anonymous Coward

    Shouldn't effect some of the budget airlines, they probably haven't got enough fuel in them to blow up ! Or at least not if it happens after being diverted over Spain due to thunderstorms....

    1. I ain't Spartacus Gold badge

      An "empty" fuel tank is way more dangerous than a full one.

  15. fpx
    Flame

    Not Unusual

    Aircraft are complex, yet few accidents happen. There are surprisingly efficient procedures for discovering, tracking and correcting issues, especially for large aircraft. Check out the airworthiness directives ("AD") database at the FAA, https://www.faa.gov/regulations_policies/airworthiness_directives/

    For example, there was one published on Monday affecting all Boeing 777 aircraft, reading in part, "We are issuing this AD to detect and correct cracks in the underwing longerons, which could result in fuel leakage into the forward cargo area and consequent increased risk of a fire or, in a more severe case, could adversely affect the structural integrity of the airplane."

    This type of language is not all that unusual in an AD. And it's only the most recent of currently 80 ADs affecting the 777. And you could make a scary headline like this article's pretty much from any of these ADs! Even "emergency" ADs, where aircraft are grounded until inspections or repairs are made before the next flight (like the 777's burning batteries issue) are not that unusual.

    This does not mean that the A350 or B777 is unsafe to fly. Flying remains the safest mode of transport, because of rules and regulations, and authorities that rigorously enforce discovery and distribution of issues.

  16. ecofeco Silver badge

    Are you kidding?

    Just, wow.

  17. Beachrider

    Well, there’s your problem...

    I miss Mythbusters...

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