How odd is a cluster of plane accidents?

http://www.bbc.com/news/magazine-28481060

by arb99 • 12 years ago

155 79 12 years ago

bbc.com

josephpmay• 12 years ago

This article gives a great insight into the nature of randomness:

http://www.wired.com/2012/12/what-does-randomness-look-like/

xsace• 12 years ago

That's the best thing I've read in days.

michaelmcmillan2• 12 years ago

I agree! That was an easy-to-read explanation of Poisson Distribution.

3JPLW• 12 years ago

Very 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

gleenn• 12 years ago

I'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• 12 years 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• 12 years ago

For reference: http://www.flightradar24.com/49.08,30.48/6

arrrg• 12 years ago

Airlines 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.)

31reasons2• 12 years ago

One thing that really surprised me is that how laid back the attitude was of commercial airliners about the Ukraine war zone. It was already in the news that they are shooting down the war planes. So basically they were betting on some Russian missile system that would identify war plane from commercial planes. I would cancel all flights from a region thats engaged in any form of airborne projectiles.

sologoub• 12 years ago

The problem is that we still don't know for sure exactly what brought down the plane. Reading various news articles, it seems that whoever decides closure of the airspace for commercial flight was betting that the longer range anti-aircraft systems would not be used in the area. Historic data seemed to support this with planes being downed either via shoulder-fired missiles or some sort of gunfire, neither of which has the range to go to the cruising altitude of a passenger liner.

This bet turned out to be bad, very bad.

I don't know of the economics involved, but I'm guessing that, aside from political reasons, the different flight paths avoiding this would have cost the airlines enough to where they didn't want to do it. Which is pretty disturbing...

The again, you don't need war to have air defenses shot down a civilian passenger jet: http://en.wikipedia.org/wiki/Siberia_Airlines_Flight_1812

pacificmint• 12 years ago

So basically they were betting on some Russian missile system that would identify war plane from commercial planes.

That's not what they were betting on at all.

They were assuming (incorrectly, as we now know) that the rebels would have smaller missiles, for example shoulder fired missiles like Stingers. Those missiles are able to shoot down planes flying at lower altitude, but they are unable to reach an aircraft at cruising altitude.

I believe the eastern Ukraine already had a closure for flights under 32,000 feet before MH 017. The military planes that were shoot down in the days before were all flying at much lower altitudes.

Surface to Air missiles that can engage planes at cruising altitude are usually only owned by state actors. They also require specially trained personal to operate them. Obviously both missiles and personal were available to whoever shot down MH 017.

billmalarky• 12 years 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• 12 years ago

Only if there were no surface-to-air missiles involved.

meowface• 12 years ago

I 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• 12 years ago

I'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.

drzaiusapelord2• 12 years ago

This 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• 12 years ago

We 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• 12 years ago

We 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".

mikeash2• 12 years ago

I 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.

scholia3• 12 years ago

Or possibly one accident. We don't know what happened to MH370....

mikeash2• 12 years ago

MH370 is not among the three being discussed.

mxfh• 12 years ago

This 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

[2]http://arxiv.org/abs/0901.3183

[3]http://www.sciencedirect.com/science/article/pii/S0378437107...

bitL• 12 years ago

Time 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_key2• 12 years ago

I 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.

shangxiao2• 12 years ago

'accident' doesn't mean that the crash happened by chance, just that it was unintentional.

frobozz• 12 years ago

An 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_key2• 12 years ago

That'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.

duaneb• 12 years ago

Accident 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• 12 years ago

When do you use the word 'accident'?

xanderstrike• 12 years ago

For unintentional, inconsequential failures. Unintentional, consequential failures are called 'negligence.'

vaadu• 12 years ago

The outcome of the shootdown was easily foreseeable given the circumstances, so I don't see how it can be described as an accident.

kazinator• 12 years ago

Indeed, even if a missile strike is accidental in the sense of mistaken identity, it is misleading to call the situation a "plane accident" or "air traffic accident". It is a military accident.

Just like when a car is blown up by driving over a mine, we don't call that a "car accident" or "traffic accident".

Doh?

zorbo2• 12 years ago

Someone driving in a car who's not paying attention for a moment and hits someone else feels like an accident to me. The same could have happened with a missile. Strictly speaking, everything has a cause. So by that definition there are no accidents.

That's all just arguing semantics though. I even agree with you that the term "accident" is not correct, despite what I wrote above. (Although I don't agree with your reasoning behind it). I'd prefer the term "incident".

Qantourisc• 12 years ago

Imo accident is an "oeps" that occurred without intend. In case of a fired missiles it's an incident. So unless someone misfired the missile it's I'd call it an incident.

drzaiusapelord2• 12 years ago

Its concerning how the Pro-Russian narrative has been formed over the shooting down of that plane. We don't call the shooting down of planes during the Cold War accidents, but somehow we do for this?

The world is coddling Putin for fear of losing his economic ties into countries that control the editorial content of much of the Western press. So we say 'accident' and we say 'supposed' ties to Russia, and we say blatant lies like 'Nazi party has taken over the Ukraine' in Western papers.

Sadly, Putin's money is held above morals and truth in Europe. Especially in Germany and France.

arjie• 12 years ago

For reference, the downing of Iran Air Flight 655 was termed in the US report[1] as a "a tragic and regrettable accident". The report goes on to use the word 'accident' many more times.

[1] http://www.dod.mil/pubs/foi/International_security_affairs/o...

notahacker2• 12 years ago

I take it your press is different from ours... http://www.buzzfeed.com/jimwaterson/british-newspapers-are-p...

Tomte• 12 years ago

I don't know which Germany you're looking at, but there is significant anti-Putin sentiment and, correspondingly, newspaper stories and commentary calling for harsh measures against Russia.

But it is somewhat tempered by the significant anti-American sentiment that we've been experiencing for a bit now. I never thought I'd see this, but it's much, much worse than when Rumsfeld talked about "old Europe" (although that was probably overblown in the European press, I don't think Americans ever understood how damaging that was).

Luckily every few years one of the big TV stations is producing another emotional, uplifting "good American" film like http://de.wikipedia.org/wiki/Die_Luftbr%C3%BCcke_%E2%80%93_N... and in those times you still feel how close we are to the U.S.

scottlocklin• 12 years ago

Erm, what country are you in? In the US, the media hysteria over what is very obviously an accident seems to be calling for WW-3. Has been since the olympics, really.

squeaky-clean• 12 years ago

I think it is silly to argue such semantics with natural language. We all know what it means when they said "accident." Something unintentional, unexpected, and unfortunate. So why do we need to go off topic and argue whether something was the correct word, when everyone is aware of the meaning implied. In this context, "crash" and "accident" are really the same. The events are random and out of control from the perspective of the airline or passengers, the people who matter in this post.

It's not like we're programming, where (hopefully) 2 != two != "two" != "2"

spacefight• 12 years ago

All crashes as mentioned:

- MH 17 http://www.aeroinside.com/item/4365/malaysia-b772-near-donet...

- Transasia in Taiwan 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-...

philh• 12 years 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.)

platz• 12 years 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• 12 years ago

The Aug 3 crash can't be the "next" crash if the "next" crash occurred on Aug 2.

shawabawa3• 12 years ago

Because if there was a crash on the 2nd and the 3rd, the one on the 3rd wouldn't be the next crash.

ermintrude• 12 years ago

I 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• 12 years ago

If these events were completely random, then we would expect them to happen in clusters. Randomness is pretty clumpy.

lilsunnybee• 12 years ago

Actual correlations can be pretty clumpy too. Definitely have to look at the overall distribution.

michaelmcmillan2• 12 years ago

I 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

sazpaz• 12 years ago

Robert 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.

vidarh• 12 years ago

The study regarding car crashes also looked into the correlation between whether or not car crashes only killed the driver or other people too, and found a clear correlation in additional deaths:

Murder-suicides leads to more "accidents" with head-on crashes etc., while "clean" suicides with nobody else involved tends to lead to an increase in "accidents" that don't risk other peoples life.

"Influence" is a fantastic book. Though it's downright chilling in how it tears apart the illusion of how much control we have of how we act.

clueless123• 12 years ago

People 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.

scholia3• 12 years ago

News 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• 12 years ago

There's no news like bad news.

It sells better. [1]

[1] http://www.psychologytoday.com/blog/wired-success/201012/why...

easyfrag• 12 years ago

Yep, 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.

notahacker2• 12 years ago

Aircraft 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.

tekromancr• 12 years ago

Oh! Lemmie try! Um, Cyber attacks! Someone found vuln in the avionics software used by that airline and has been fucking with the planes. Um, and the culprit is... A colalition of anonymous disenfranchised russian/ukranian teenage hackers who have been trained by the illuminati.

Yea, I think people will buy that.

tpeng• 12 years ago

The Werther effect could be another explanation for clusters of airplane crashes:

https://fc.deltasd.bc.ca/~dmatthews/FOV2-00074762/S02DB0598....

calinet62• 12 years ago

This 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• 12 years ago

That'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?).

calinet62• 12 years ago

You 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.

ackfoo• 12 years ago

While 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.

lifeisstillgood2• 12 years ago

Sadly if humans are too stupid to fly them, we are certainly too stupid to tell a computer how.

robotresearcher• 12 years ago

That'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.

bostonpete• 12 years ago

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.

Sure, anything is possible. But your theory involves so many leaps that it's difficult to take seriously.

MaybiusStrip• 12 years ago

The whole point of the article was that clustering is not unusual when it comes to random events. It's actually rarer for random events to be evenly distributed. There's nothing really begging to be explained here, especially not by such a bold, unsubstantiated claim.

lifeisstillgood2• 12 years ago

My 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• 12 years 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• 12 years ago

Yesterday 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.

jdcryans• 12 years ago

For 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

How odd is a cluster of plane accidents?

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