Courtesy Federal Aviation Administration

Background

The runway safety area (RSA) enhances the safety of aircraft that undershoot, overrun, or veer off the runway. The RSA provides a clear, graded area which provides additional space for pilots to bring their aircraft to a safe stop. Though RSAs vary in size by runway, they can be as large as 500 feet wide and often extend 1,000 feet beyond each end of the runway. Many airports were built before the current RSA dimensional standards were adopted in the 1980s. In some cases, it is not practicable to achieve the full standard RSA because there may be a lack of available land. There also may be obstacles such as bodies of water, highways, railroads, and populated areas or severe drop-off of terrain.

The FAA began conducting research in the 1990s to determine how to improve safety at airports where the full RSA cannot be obtained. Working in concert with the University of Dayton, the Port Authority of New York and New Jersey, and the Engineered Arresting Systems Corporation (ESCO, now Runway Safe Inc., of Logan Township, New Jersey), a new technology emerged to safely arrest overrunning aircraft. Engineered Materials Arresting Systems (EMAS) use crushable material placed at the end of a runway to help stop an aircraft that overruns the runway end. The tires of the aircraft sink into the lightweight material and the aircraft rapidly decelerates as it rolls through the EMAS bed.

Benefits of the EMAS Technology

EMAS technology improves safety benefits in cases where land is not available for an RSA of standard dimensions. A standard EMAS installation will stop most aircraft overrunning the runway at 70 knots (approximately 80 miles per hour).

EMAS Manufacturers

Runway Safe acquired the EMASMAX® product range from ESCO as of February 2020. Runway Safe is the sole manufacturer of EMAS products that meet the FAA standards of Advisory Circular 150-5220-22B, Engineered Materials Arresting Systems for Aircraft Overruns.” Currently, Runway Safe has two EMAS systems, the cellular concrete block system called EMASMAX® and a silica foam system called greenEMAS®.

The FAA reviews and accepts each EMAS proposal prior to installation.

EMASMAX® is the latest, most durable version of Runway Safe’s block based EMAS, developed with and technically accepted by the FAA. EMASMAX® arrestor beds are composed of blocks of lightweight, crushable cellular cement material.

Runway Safe’s greenEMAS® is a foamed silica bed which is made from recycled glass and is contained within a high-strength plastic mesh system anchored to the pavement. The foamed silica is poured into lanes bounded by the mesh and covered with a poured cement layer and treated with a topcoat of sealant. 

Both EMAS products are located at the end of the runway and are typically the full width of the runway. The bed length and offset from the end of the runway depends on the airport configuration and the aircraft fleet using the airport.

Current FAA Initiatives

The FAA’s Office of Airports has helped facilitate RSA improvements at more than 500 commercial service airports. This means that all practicable improvements, including the use of EMAS technology, have been made at approximately 1,000 runway ends at these airports. These RSAs have been improved to full standards or to the extent practicable including the relocation of FAA-owned navigational equipment. As a result of the success in addressing commercial service airport RSA’s, the Office of Airports has started a similar strategy to improve General Aviation RSA’s across the country.

EMAS Arrestments

To date, EMAS safely stopped 22 overrunning aircraft, carrying 432 crew and passengers aboard those flights.

Engineered Material Arresting System (EMAS) | Federal Aviation Administration