FAA Issues Engineered Materials Arresting System (EMAS) Fact Sheet

December 29, 2006 // Published as a news service by IHS

The RSA requirement is in place in case an aircraft overruns, undershoots or veers off the side of the runway.

According to the FAA, the most dangerous of these incidents are overruns, but since many airports were built before the 1,000-foot extension was adopted some 20 years ago, the area beyond the end of the runway is where many airports cannot achieve the full standard RSA, due to obstacles such as bodies of water, highways, railroads and populated areas or severe drop-off of terrain.

Even though the FAA provides federal funding to support RSAs at commercial airports, it still may not be practical for some airports to achieve the standard RSA. In the 1990s, the FAA began conducting research to determine how to ensure maximum safety at airports where the full RSA cannot be obtained.

Working with the University of Dayton, the Port Authority of New York and New Jersey, and the Engineered Arresting Systems Corporation (ESCO), a new technology emerged to provide an added measure of safety. An Engineered Materials Arresting System (EMAS) uses materials of closely controlled strength and density placed at the end of a runway to stop or greatly slow an aircraft that overruns the runway. To date, crushable concrete is the only system that meets FAA standards.

An EMAS arrestor bed causes a plane's tires to sink into the lightweight concrete upon impact. The aircraft is decelerated by having to roll through the material, the FAA said.

EMAS Technology Benefits
According to the FAA, EMAS technology provides safety benefits in cases where land is not available or where it would be very expensive for the airport sponsor to buy the land off the end of the runway.

The EMAS technology also provides an added measure of safety at airports where it is not possible to have the standard 1,000-foot overrun. EMAS is in place at 14 U.S. airports and on 21 runways. Installation is on tap at four additional airports.

A standard EMAS installation extends 600 feet from the end of the runway. An EMAS arrestor bed can be installed to help slow or stop an aircraft that overruns the runway, even if less than 600 feet of land is available.

The FAA Office of Airports prepared its RSA improvement plan for the runways at roughly 575 commercial airports in 2005. The plan enables the agency to track the progress and to direct federal funds for making all practicable improvements, including the use of EMAS technology.

EMAS Arrestments
The technology prevented aircraft from overrunning the runway in three incidents. In several other cases, the technology prevented injury to passengers and damage to the aircraft, including:

• May 1999 - A Saab 340 commuter aircraft overran the runway at JFK.
• May 2003 - Gemini Cargo MD-11 was safely decelerated at JFK.
• January 2005 - A Boeing 747 overran the runway at JFK.
• July 2006 - Mystere Falcon 900 airplane ran off the runway at the Greenville Downtown Airport in South Carolina.

Source: U. S. Federal Aviation Administration (FAA).