POSTED BY

Lisa Katayama

AT 11:10 AM
Thursday August 27, 2009

Airports and Travel • Vehicles

accidents • airplanes • ICAT • MIT

Why so many plane crashes in 2009?

w19080917.jpgIt's been a pretty bad year for airplane accidents &mdash 36 and (hopefully not) counting, including a cargo plane crash in the Congo just yesterday that resulted in seven fatalities. Is it just a series of freak accidents or a glitch in the airplane industry? To find out, I interviewed R John Hansman, aeronautics professor at MIT and director of ICAT.

BBG: Is there a bigger reason for the onslaught of plane crashes in 2009 or is it just bad luck?

RJH: There have been times in the past where a series of accidents had exactly the same cause and there was a clear problem to fix. In the early 70s, we didn't understand the meteorology of windsheer, and sudden changes in wind direction were causing control problems. 15-20 years ago, the leading cause of fatal crashes was controlled flight into terrain &mdash that's when a pilot takes a perfectly good airplane and flies it into the ground. This was solved by enhanced ground proximity warning systems, which give the crew warning if they're about to fly a plane into the ground.

That's not the case here. It's been a bad year, but there don't seem to be any systematic problems. The accidents have all been quite different. Commercial aviation is incredibly safe &mdash only about one in every 10 million departures result in accidents in the developed world. It's possible, though, to have a cluster of rare events like this. This year looks bad, but the last couple of years have looked incredibly good. What you're seeing is an effect of statistics in small numbers.

BBG: Human error is involved in more than half of all airplane accidents. Why can't we fix this?

RJH: It's easy but not very useful to identify human failure as the cause of an accidents. More importantly, what caused the human to make the error? Was there a problem in the design of the aircraft, in the procedure, or in terms of fatigue of the crew? It's generally a fair assumption that pilots don't want to be put at risk. The rate of human error has gone down &mdash as a percentage base, it's still high, but that's because the number of overall accidents has declined significantly.

BBG: What about the Air France crash? Is that still a mystery?

RJH: Parts of it will always be a mystery. We have a pretty clear indication that what started the problem was icing on the air speed probes. It was known that the probes on this aircraft needed to be changed, but it wasn't seen to be that urgent. It may have been that the combination of the faulty probes and thunderstorm conditions may have been too hard to manage. The plane had also gone into a simpler flight control system, or alternate mode, which limits what the pilot can do to minimize the possibility of human error. We have a message from the airplane that they went into alternate mode, but we don't have the flight data recorder so we'll never know how that manifested.

*Statistics and image courtesy of Planecrashinfo.com

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10 Comments

randalll

#1 – 11:53 AM August 27, 2009

"that's when a pilot takes a perfectly good airplane and flies it into the ground"

I'm sure he wasn't going for laughs there, but that made me crack up.

Zan

#2 – 5:10 PM August 27, 2009

I still blame Steven Johnson

Hunter

#3 – 8:46 PM August 27, 2009

I'm pretty sure it comes down to luck.

rommel armogan

#4 – 9:51 PM August 27, 2009

how many plain crash in 2009

strider_mt2k

#5 – 3:45 AM August 28, 2009

Why should companies spend money on maintenance when they can just keep it?

I mean the owners don't fly on 'em so it's really just a matter of managing the financial liabilities based on the odds, right?

Now where are those 500 dollar earbuds of mine...

WalterBillington

#6 – 4:28 AM August 28, 2009

39 crashes? Some apples and pears here - Check the qualification of the safety stats - "in the developed world". Weren't many of the crashes outside that safezone? Indonesia. Philippines. The "who's looking?! it's too hot" approach to maintenance and training. Plus the trade in used aircraft means these babies are still trailing around the skies above Gambia and such. Now the pilot don't wanna die, but he ain't fixin' the engines now is he?

So we're likely to see an increasing number of aircraft going down, simply because there are more in the air. In dodgy neighbourhoods.

And Air France - JFC, why does anyone want to fly into a storm? RIP and all. But turn tail and run! I've totally exited a diverted aircraft when informed by a shaken pilot he'd been instructed back into the stormy air by the airline. No thankyou.

I know people in aircraft structured finance, and believe me, they carry lists of aircraft flown by developed world airlines they won't fly (they check the id numbers, and simply walk off if they've made a mistake and ended up on that plane), and simply never, ever fly the rustbuckets. Which means anything except BA, Virgin, etc etc. Aeroflot? Buy your grave.

I've flown a lot in my time, big, small, upside down, inside out. They key to safety is - stick with the people who know what they're doing, and don't buy off-market components.

Boring so sorry - let's compare to road stats.

cmdrfire

#7 – 6:56 AM August 28, 2009

@WalterBillington - what you've said is mostly bullhocky. Jetliners regularly fly through, and above storms with no incident at all.
The airlines of developing nations still need to conform to international standards if they are to fly.
And outside of some civil aircraft used by private operators on a charter basis, there's no such thing as a "rustbucket". The aircraft flown by US carriers can often be up to twenty years (or more!) old, and are still perfectly servicable aircraft.
Likewise, Aeroflot operates a reasonably modern and well-kept fleet and these days has a pretty good safety record.
One of the things that we tend to forget is that there are more hours being spent by more aircraft in the air - so it's incredible that the number of accidents generally stays level, or increases only slightly. The safety rate per hour flown is actually increasing.
I refer you all to Patrick Smith's excellent Ask the Pilot columns in Salon; good places to start are here:
http://www.salon.com/tech/col/smith/2009/07/24/askthepilot328/index.html
and here:
http://www.salon.com/tech/col/smith/2007/09/21/askthepilot246/index.html
The full archive - pretty much every article is worth reading, incidentally - is here:
http://dir.salon.com/topics/ask_the_pilot/

Robert Holland

#8 – 1:31 AM August 29, 2009

Most, if not all aircraft "accidents" can be prevented by technology that is readily available now. Attaching piezoelectric or piezoceremaic sensors to most every kind of physical joint on the structure itself or even the sensors themselves with an automatic feedback loop would solve most problems. For the sensors it can monitor the resulting signal against a "normal" signal to alert the pilots to problems. With so called "smart memory" washers any kind of bolted joint can be fixed on the fly. The materials react to changes in the electrical current flowing through them and expand to re tighten the bolts to a certain extent until a human can do so on the ground. Either way the kinds of tragedies suffered this year are unnecessary and easily fixed.

TDE

#9 – 1:53 AM September 1, 2009

Geomagnetic storms. The stress the earth-magnetic-field is in. Solarcycle 24 is causing a lot of havoc the coming three years! Expect a lot more strange phenomena and anomalies.

ahsan raja

#10 – 6:44 AM September 7, 2009

My cousine Flt Lt shehryar nisar is martyred due to air crash his air craft f7(chinese) made Got fire why so stupid air planes made that are fired for flying for saving the village and he does not ejected
go on google write shehryar nisar and then select the option of in the memorary of shehryar nisar shaheed u wiil see its video and pictures chinese planes r stupid

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