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]