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How odd is a cluster of plane accidents?
- josephpmay 12y agoThis article gives a great insight into the nature of randomness: http://www.wired.com/2012/12/what-does-randomness-look-like/ http://www.wired.com/2012/12/what-does-randomness-look-like/
- xsace 12y agoThat's the best thing I've read in days.
- michaelmcmillan 12y agoI agree! That was an easy-to-read explanation of Poisson Distribution.
- 3JPLW 12y agoVery related is our perception of randomness and our surprise at a cluster of accidents. It falls out quite nicely: if plane crashes are a poisson process, then, on average, they happen in clusters of e. See: Celebrities die 2.7183 at a time: http://ssp.impulsetrain.com/celebrities.html http://ssp.impulsetrain.com/celebrities.html
- gleenn 12y agoI'm pretty happy someone actually wrote something about this, I was surprised I didn't hear any news outlets talking about the connection beyond just mentioning the other accident. I'm also happy to see some at least slightly non-trivial statistics in the mainstream. One glaring point though: the liklihood of another crash might not be high given whatever statistics, but those don't reflect the fact that someone shot a missile at one of those planes. I might risk a flight in Africa or Taiwan or where-ever, but you won't see me flying anywhere near Russia/Ukraine anytime soon even though people obviously thought this was a perfectly reasonable thing to do.
- guard-of-terra 12y ago"but you won't see me flying anywhere near Russia/Ukraine anytime soon" Actually most flights from Europe to East Asia fly over Russia now while carefully avoiding Ukrainian airspace. So if you really need there and want to avoid Russian airspace, you'll have to fly via Africa or Americas or possibly transsiberian rail. By glancing at flightradar24: Everybody is scared to fly over Ukraine, except for Russian (Transaero) and some Turkish planes bound to Russia who fly over central Ukraine just fine.
- kaeawc 12y agoFor reference: http://www.flightradar24.com/49.08,30.48/6 http://www.flightradar24.com/49.08,30.48/6
- gpmcadam 12y agoQuite interesting. When you zoom out slightly further you can see a very visible avoidance of the entire country: http://puu.sh/ar1f4/b7231c1b24.png http://puu.sh/ar1f4/b7231c1b24.png
- nawitus 12y agoThere's now multiple Western airlines flying over Ukraine. Most planes simply avoid the Eastern parts of Ukraine.
- arrrg 12y agoAirlines are now paying extra-close attention to this, so I really wouldn’t worry at all when flying through this region. (No one is flying over Ukraine or conflict regions inside Ukraine anymore, anyway, but there is really no reason at all to worry about Russia.) It’s rare that civilian airplanes are shot down with weapons, anyway. I don’t think there is any reason to worry. This won’t happen to you. (Oh, now, don’t get me wrong, were I to fly through this region I would be more scared than I would otherwise be. However, that would be irrational on my part and in many ways an involuntary reaction and no reason to change my plans.)
- deleted 12y ago[deleted]
- sjolsen 12y agoThe "chance" here is the probability of the second crash will happen given the first crash happens. Because the first crash is given, its probability should be taken to be 1. There's also whether the probability of a crash occurring on any given day is actually 1/365, but that's another issue.
- jerf 12y agoNo. Once you take an event as given, its probability is now 1. In conventional notation, P(A|A) = 1 ("the probability of A given A is 1"). For the sake of argument, it has now occurred, and the probability of an event that has already occurred is 1, just as the probability of an event that didn't occur in the past is now 0.
- deleted 12y ago[deleted]
- billmalarky 12y ago"the most likely maximum number of crashes of commercial planes with over 18 passengers in any eight-day window over 10 years is exactly three". So if another crash occurs are we allowed start the conspiracy theories?
- karlkatzke 12y agoOnly if there were no surface-to-air missiles involved.
- meowface 12y agoI think some group shooting down planes with surface-to-air missiles would constitute the definition of some sort of a conspiracy. Just not a very subtle one.
- jameshart 12y agoI've always argued that clusters of plane accidents are reassuring signs that they truly are random. If plane crashes happened with precise, predictable regularity, once every three weeks, say, then that would be a sign that there was some sort of terrible uncontrollable force at work in the world.
- drzaiusapelord 12y agoThis is such a good point. Sometimes I have to explain to people that coincidences aren't weird. It would be weird if there no coincidences. But that usually detracts from some of their spiritual/political beliefs and its quickly dismissed.
- Someone 12y agoWe thought solar eclipses and new moons were signs of terrible uncontrollable forces, too, but we know better now. AFAIK, we never thought that of solar maximums, so if plane crashes happened every three weeks, I doubt we would think them signs of terrible forces. Also, I would know when not to book a flight, as would everybody else.
- jessaustin 12y agoWe thought solar eclipses and new moons were signs of terrible uncontrollable forces, too, but we know better now. I don't think that eclipses are in any sense "controllable".
- mikeash 12y agoI feel it's important to point out that this is not a cluster of three airliner accidents. It's a cluster of two accidents and one crash due to military action. While they presumably didn't intend to shoot down an airliner, the only accidental part was that they killed different people from who they wanted to kill. I don't think this affects the probability discussion much, but it's good to call it what it is.
- mxfh 12y agoThis paper argues it's a poisson distribution: Time-evolving distribution of time lags between commercial airline disasters[1] while others disagree: In the case of plane accidents, the authors of Ref. 7[1] found that the time lag between commercial airline disasters and their occurrence frequency could be well described by time-dependent Poisson events. On the other hand, authors of Ref. 8[3] have found that beyond certain timescales the time dynamics of both plane and car accidents are not Poissonian but instead long-range correlated.[2] [1]http://arxiv.org/abs/physics/0509092 http://arxiv.org/abs/physics/0509092 [2]http://arxiv.org/abs/0901.3183 http://arxiv.org/abs/0901.3183 [3]http://www.sciencedirect.com/science/article/pii/S0378437107003111 http://www.sciencedirect.com/science/article/pii/S0378437107...
- bitL 12y agoTime between disasters has exponential distribution (or the number of disasters in given time adheres to Poisson distribution). Something we were taught at the university.
- low_key 12y agoI don't agree with the term 'accident' for crashes because they can always be attributed to causes, not just chance. This is even more true when missiles are involved.
- shangxiao 12y ago'accident' doesn't mean that the crash happened by chance, just that it was unintentional.
- frobozz 12y agoAn event doesn't have to be purely random (whatever that means) to be an accident. An accident is something that happens unintentionally. Though I'm sure many crashes are down to genuine negligence, I'd be surprised if most crashes are deliberate, even indirectly (e.g. "Whoops! I've cross-threaded this bolt, oh well, I'm sure it will be fine" vs "Ha Ha! I'll cross-threaded this bolt. That'll make the plane crash one day!").
- low_key 12y agoThat's true, I guess I didn't fully describe what I meant. It seems to me that when people use 'accident' to describe something they are trying to remove attribution or disconnect causes.
- shangxiao 12y agoI don't think that people do that at all. All accidents are investigated thoroughly to find the cause(s).
- duaneb 12y agoAccident just means unintended. And while there are causes, they may now well be unknowable, in which case a statistical look is probably the most interesting look you can justifiably make.
- IvyMike 12y agoWhen do you use the word 'accident'?
- spacefight 12y agoAll crashes as mentioned: - MH 17 http://www.aeroinside.com/item/4365/malaysia-b772-near-donetsk-on-jul-17th-2014-aircraft-was-shot-down http://www.aeroinside.com/item/4365/malaysia-b772-near-donet... - Transasia in Taiwan http://www.aeroinside.com/item/4389/transasia-at72-at-makung-on-jul-23rd-2014-impacted-buildings-on-approach http://www.aeroinside.com/item/4389/transasia-at72-at-makung... - Swiftair MD 83 in Africa http://www.aeroinside.com/item/4393/swiftair-md83-over-mali-on-jul-24th-2014-aircraft-lost-altitude http://www.aeroinside.com/item/4393/swiftair-md83-over-mali-...
- philh 12y ago> In fact, Ranter says it is more common for an accident to happen just one day after another crash than two, three or more days later. As written, a poisson distribution wouldn't explain this. If you have a crash on day 0, then a crash on day 1 is no more likely than a crash on days 2, 3, etc. Day 1 is the day most likely to have the next crash, but it's no more likely to have any crash. (It could easily be the case that Ranter actually found "...just one day after the previous crash than two, three or more days later", and this subtlety got lost somewhere down the line.)
- deleted 12y ago[deleted]
- TheCoelacanth 12y agoNo, because if a crash occurs on both Day 1 and Day 2, then the next crash was on Day 1. The probability of a crash occurring on each day is the same, but the probability of the next crash occurring is higher for earlier days.
- pepon 12y agoI agree with you, but I am not sure about this: P(A) * P(Not A) * P(Not A) = P(Not A) * P(Not A) * P(A) P(A) > P(Not A) * P(Not A) * P(A) Also, of course these are not independent events: if a plane has an accident for some reason, all the future flights take extra measures to avoid the problem that caused the accident and other related problems.
- platz 12y ago"But the chance the next crash is on 3 August is (364/365) x (1/365), because the next crash occurs on 3 August only if there is no crash on 2 August." Why is a crash on 3 August dependent on there being no crash on 2 August? Surely there could be crashes on both 2 August and 3 August.
- UrlichtZwei 12y agoThe Aug 3 crash can't be the "next" crash if the "next" crash occurred on Aug 2.
- shawabawa3 12y agoBecause if there was a crash on the 2nd and the 3rd, the one on the 3rd wouldn't be the next crash.
- ermintrude 12y agoI read a book once - I think it was the Gift of Fear (but I might be wrong) - that said that plane crashes often occur in clusters, same with other tragedies like mass shootings at schools etc. The author suggested this was because people who might do those things - or in the case of pilots, pilots who might want to commit suicide and take the plane down with them - get prompted to act when they see other incidents have occurred. So according to that author, these events are not random. Obviously a civilian plane being shot down would lie outside this theory (he suggested more plane crashes were due to pilot depression than mechanical fault/other factors).
- lotsofmangos 12y agoIf these events were completely random, then we would expect them to happen in clusters. Randomness is pretty clumpy.
- lilsunnybee 12y agoActual correlations can be pretty clumpy too. Definitely have to look at the overall distribution.
- michaelmcmillan 12y agoI don't think mass shootings can be considered to be random events, although they probably occur in clusters - I think that's due to the extensive media coverage. "Why does a psychiatric expert on these phenomena personally advise mainstream media outlets about how to handle these situations - and they do exactly the opposite time and again?" [1] [1] https://www.youtube.com/watch?v=Stc42j4Nz2w https://www.youtube.com/watch?v=Stc42j4Nz2w
- sazpaz 12y agoRobert Cialdini also brings the same theory in his book Influence. Not only that a tragedy prompts other to the same action, but he showed some studies where a type of tragedy prompted a seemingly irrelevant event. For example, 2 days after a suicide appearing on the news, it is significantly (don't remember the exact numbers) more likely for there to be a plane crash. He attributes this to the fact that some pilots that have had suicidal thoughts are triggered by the suicidal news. Another interesting study looked at how mortality rates of car accidents are higher after suicide-related news. This study found a surprising number of car deaths in which the driver was stepping on the gas pedal, instead of the break, which might be an indicator of suicide.
- clueless123 12y agoPeople pay more attention to airplane accidents right after a large accident event.. Google plane accidents and you will see that they happen all the time, they just don't get the world wide news coverage.
- scholia 12y agoNews is a fashion industry. One big "dog mauls child" story will be followed by other "dog mauls child" stories that would otherwise not have been reported. The difference is that they are "news" now when they weren't news before....
- bostik 12y agoThere's no news like bad news. It sells better. [1] [1]: http://www.psychologytoday.com/blog/wired-success/201012/why-we-love-bad-news http://www.psychologytoday.com/blog/wired-success/201012/why...
- easyfrag 12y agoYep, summer 2001 was the "Summer of the Shark Attacks" because of a couple of high-profile incidences. The news media played it up as some sort of epidemic although there was no significant difference in the numbers. This went on until September when a bigger story came long.
- notahacker 12y agoAircraft accidents are common; commercial airline accidents, especially those apparently happening in mid-air are very rare. Even thirty year old trijets operated in Africa crash infrequently enough to warrant global news coverage, albeit not news coverage that many people pay much attention to or that the BBC sees fit to create a live update page for. What's actually a far bigger coincidence is that there were no fatal 777 crashes in the first 20 years of a >1200 aircraft production run until this year, when two aircraft belonging to the same airline were both total losses in apparently unrelated cases of apparent foul play. Whilst I can't conceive any conspiracy theory linking the two that would be credible even by the low standards of the average conspiracy theory, that's a far bigger statistical anomaly.
- tpeng 12y agoThe Werther effect could be another explanation for clusters of airplane crashes: https://fc.deltasd.bc.ca/~dmatthews/FOV2-00074762/S02DB0598.2/Cialdini%20airplane%20studies.pdf https://fc.deltasd.bc.ca/~dmatthews/FOV2-00074762/S02DB0598....
- calinet6 12y agoThis is absolutely correct and insightful. Glad to see it on the BBC. Now here's a scary question: when you want to give someone a bonus because of their successful performance over the last 6 months, how likely is it that their string success is a coincidence? You're forced to make a similar conclusion, and if you don't, think about why you have the bias you do.
- yaks_hairbrush 12y agoThat's not a scary question. One could simultaneously believe that an employee's performance was coincidence, but still give that employee a bonus (why not reward luck, after all?).
- calinet6 12y agoYou don't reward luck because the negative effects of individual bonuses on the entire workforce cause more harm. You recognize the truth: that your whole team is responsible for working together to solve the problems of the company, which are necessarily complex and large (otherwise, you'd only need one person) and individual salaries are based on their baseline skills and abilities in that context. Visible public reward of individuals for work that's perceived (and truly required) to be a team effort is visibly detrimental.
- deleted 12y ago[deleted]
- ackfoo 12y agoWhile it is impossible to reduce chaotic systems to individual factors, and it is likewise impossible to predict the effect of an individual factor upon the system as a whole, it is certainly possible for one factor with a global effect to move the entire system towards or away from a probable outcome. If we postulate that, now absent the selection pressures that have shaped human intelligence over the last few million years or so, human intelligence is likely to decline, then we can ask ourselves where this decline might be likely to first show up in the chaotic system of human endeavour. One possible answer is that it will appear first at the boundary layers: the places where a critical level of human intelligence is required to keep a complicated task operating. I propose that flying passenger aircraft is such a task. A critical level of intelligence must be maintained by a very large number of people in order to keep passenger aircraft in the air. Everyone, from designers to manufacturers, to QC, to maintenance to pilots to airline management has to function above a certain critical level to perpetuate the activity. It is possible that clusters of aircraft accidents are purely random and part of the complex system that is air travel. However, it is possible that clusters of aviation accidents represent crossings of the boundary layer resulting from the change in a global factor, like human intelligence, that has moved the entire system probabilistically. The details of some recent accidents should give us pause. The series of over-control/mis-control accidents including AF447, Colgan Air and others defy reasonable explanation, and they appear to have no precedent in recent passenger aviation. MH370 and MH17, so far as we can see, have no reasonable explanation other than unaccountable human behaviour (failing to communicate over the course of seven hours flying in the case of MH370, and navigating over a war zone in the case of MH17). It is possible, although certainly not provable at this point, that we are simply becoming too stupid (in general) to fly passenger aircraft safely. It may be time to switch to fully automated aircraft systems.
- lifeisstillgood 12y agoSadly if humans are too stupid to fly them, we are certainly too stupid to tell a computer how.
- robotresearcher 12y agoThat's not true at all. The computers can do control corrections much faster than humans. A human could not fly a quadrotor drone by controlling the current to the individual motors: computers fly them just fine. Very often we know how to control things but humans can't do the computation fast enough.
- lifeisstillgood 12y agoMy question is how far has decades of cut throat competition eroded the safety and maintenance standards of all airlines? Minimum standards are high - and well respected. But if you shave off costs - even if each one is trivial - put back investment, dial back on the training, will I have a cumulative effect? In short, when will air travel trend towards rail and road for accidents ?
- WalterBright 12y ago> My question is how far has decades of cut throat competition eroded the safety and maintenance standards of all airlines? It hasn't. They're safer than ever. But keep in mind that while airliners are very robust against all kinds of mechanical failures, human errors, and natural events, they are not designed to withstand battle damage or to have any sort of countermeasures. Their only safety from attack is they fly at high altitude, out of range of small arms.
- Coincoin 12y agoYesterday in Toronto, a plane made an emergency landing. The news ignored it as just an usual everyday thing, because you know, it happens everyday... Just kidding, they actually called it a "multiplication" of aviation incidents.
- abruzzi 12y agoThe is essentially the Texas Sharpshooter fallacy. https://yourlogicalfallacyis.com/the-texas-sharpshooter https://yourlogicalfallacyis.com/the-texas-sharpshooter
- jdcryans 12y agoFor those interested, a good source for a lot of publicly reported crashes, accidents, incidents and whatnot is The Aviation Herald. Here's the list of all their recorded crashes sorted by occurence date (toggle the icons next to "Filter" to see more kinds of events): http://avherald.com/h?list=&opt=7681 http://avherald.com/h?list=&opt=7681