There’s a simple reason why this Boeing 737 wasn’t destroyed this week at Jiuzhai Huanglong Airport, China, and instead destroyed this concrete runway using its landing gear: it’s neither a runway nor concrete. At least, not in the traditional sense.
It’s something called EMAS, Engineered Materials Arresting System, and it may save your life one day.
What is it?
EMAS is a paving system made of “foamed concrete”, a “bed of cellular cement blocks encased in an environmental cover that is placed at the end of a runway to decelerate an overrunning aircraft in an emergency.”
How does it work?
When the aeroplane overruns the runway, it crushes the foamed concrete in a process that gently stops the aircraft without causing catastrophic damage. This invention can truly save the day.
How important this may be to save lives?
During the last 15 years there have been more than 30 runway overrun accidents per year involving commercial aircraft. 25 per cent of them were classified as “major accidents”, involving significant damage and injuries or facility. And 10 per cent resulted in fatalities. That’s more than one thousand people dead since 1995.
Which airports have EMAS?
Surprisingly, EMAS is not an obligatory safety system in the US or anywhere in the world. By the end of 2010, only 51 runway ends at 35 airports in the US had implemented this system instead of the obligatory Runway Safety Area. The RSA is just a cleared space that is not designed to stop the aircraft and may end in disaster.
Outside the US, only a few airports around the world — like Jiuzhai Huanglong in China or Madrid-Barajas in Spain — have EMAS.
After reading the accident statistics, I wish it became obligatory in every major airport through the world. [Tiexue (Chinese) and Icao (PDF) via Chinese defence Blog]
DarthDVD
Wednesday, December 21, 2011 at 8:28 AMsome how i can see concrete being sucked into the engine and causing more problems.
Dean
Wednesday, December 21, 2011 at 8:38 AMIf you’re alive after an accident like this, who cares how damaged the plane engine is . . . . .
DarthDVD
Wednesday, December 21, 2011 at 9:00 AMI wasnt thinking cost to repair.. i was thinking along the lines of smashed up on fire leaking fuel and fire everywhere.
Graeme
Wednesday, December 21, 2011 at 12:53 PMJet engines run on kerosene. Kerosene is only really flammable if it’s in a fine vapour, so unless it’s under high pressure and pumped through a small aperture the risk of a large fire is small. If you want to check, pour out a puddle of kerosene and chuck lit matches in it. The matches will go out.
EMH
Wednesday, December 21, 2011 at 11:25 AMIf these engines are significantly damaged they are going to be on fire too. The fire will rapidly spread to the fuel tanks and if you are not out of the plane be then you may not be going to get out.
However the nosetyres have chines which are designed to deflect debris and I see no evidence in the photos that the engines are in any danger of FOD (foreign object damage).
Chris
Wednesday, December 21, 2011 at 12:01 PMI’m pretty sure engines are run in reverse in that stage of landing…
therefore nothing would really get sucked in
Daniel
Wednesday, December 21, 2011 at 12:33 PMJets running in reverse will still suck in air – that’s how they run.
Instead the thrust is pushed back instead of flowing out the back of the jet.
Ollie
Wednesday, December 21, 2011 at 12:46 PMAre you for real dude? You seriously think they stop and reverse the rotation of the blades in the turbine? Within 2 or 300m of touching down?
Best be looken that sh!t up before posting dumb arse comments fella.
Here ya go: http://en.wikipedia.org/wiki/Thrust_reversal
Just This Guy ...
Wednesday, December 21, 2011 at 2:33 PMY’all need to re-read the bit that says “What is it?”
It’s for emergencies. End of runway stuff. Not day to day use, so aircraft damage comes second to safety. But there’s no harm in trying to minimise aircraft damage at the same time.
That’s what this stuff does.
light487
Wednesday, December 21, 2011 at 9:12 AMSo the plane in these photos, I am assuming it was a test plane?
Dan
Wednesday, December 21, 2011 at 9:49 AMwell, i don’t think all those photographers just happen to be there perfectly in time to set up all their equipment and get photos of a plane that just happened to overrun a runway…
S0ULphIRE
Wednesday, December 21, 2011 at 10:13 AMPlus video camera on massive boom :p yeah I’d say it’s a safe bet
Sylphier
Wednesday, December 21, 2011 at 12:06 PMThe tag on the plane translates to:
“China Academy of Civil Aviation Science and Technology”
So yeah, test plane doing demo / proof of concepts I believe.
Sean
Wednesday, December 21, 2011 at 9:53 AMA small chance of that happening might be better than a large chance of running into something solid at the end of the overrun and then bursting into flames.
Kim
Thursday, December 22, 2011 at 12:49 AMOr running into a car just past the runway and killing a child, as a Southwest flight did in Chicago some years ago. 6-year-old boy if I recall correctly, he was the only fatality of that incident.
Kendal
Wednesday, December 21, 2011 at 12:00 PMI <3 potholes.
jase
Wednesday, December 21, 2011 at 3:08 PMGot a cheaper and easier method, learn to fly better.
A Rod H
Wednesday, December 21, 2011 at 5:04 PMI’d have thought the plane model would have been a clue, as it’s a Boeing 737 series 300. Something they made 1113 of starting in 1981, so it’s quite likely to be a plane very close to its end of lifespan.
Cause looking at the wiki page, a 737-200 with the optional Upaved Strip Kit might’ve been a better choice, but they’d have to grabbed one from Canada as that’s apparently where all of that type reside now.
BentBlade
Thursday, December 22, 2011 at 1:55 AMmain gear is behind the engines – material disrupted by the nose gear would have the potential to FOD the engines, which should be running “full tilt” for the thrust reversers. Not sure if the engines would see damage or not.
tim
Thursday, December 22, 2011 at 11:33 AMwow, all the aircraft engineers / damage assessment specialists are out in force here today…