The material's manufacturer, Engineered Arresting Systems Corp., describes what it is and how it's supposed to work: "EMAS is consisted of a bed of cellular cement material manufactured in the form of engineered block components that are strategically placed at the overrun end of a runway. The EMAS predictably and reliably crushes under the weight of an aircraft, providing deceleration and a safe stop."

The company also says the material can be installed around "high-value public and private buildings" to stop "threat vehicles." A truck carrying explosives, say.

The arresting systems already have saved some planes, including a couple of commercial flights full of passengers: a Mexicana Airlines Airbus A320 at Chicago's O'Hare International Airport in 2008; a PSA Airlines Bombardier CJR200 in West Virginia in 2010; and, perhaps most spectacularly, a 747 cargo jet at JFK in New York City in 2005.

Aspiring EMAS nerds need to watch the video below from the manufacturer. It actually does a great job explaining how the system works, complete with video from a live test with a real airliner.

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