Engineered materials arrestor system


An engineered materials arrestor system, engineered materials arresting system, or arrester bed is a bed of engineered materials built at the end of a runway to reduce the severity of the consequences of a runway excursion. Engineered materials are defined in FAA Advisory Circular No 150/5220-22B as "high energy absorbing materials of selected strength, which will reliably and predictably crush under the weight of an aircraft". While the current technology involves lightweight, crushable concrete blocks, any material that has been approved to meet the FAA Advisory Circular can be used for an EMAS. The purpose of an EMAS is to stop an aircraft overrun with no human injury and minimal aircraft damage. The aircraft is slowed by the loss of energy required to crush the EMAS material. An EMAS is similar in concept to the runaway truck ramp or race circuit gravel trap, made of gravel or sand. It is intended to stop an aircraft that has overshot a runway when there is an insufficient free space for a standard runway safety area. Multiple patents have been issued on the construction and design on the materials and process.
FAA Advisory Circular 150/5220-22B explains that an EMAS may not be effective for incidents involving aircraft of less than 25,000 pounds weight. It also clarifies that an EMAS is not the same as a stopway, which is defined in FAA Advisory Circular 150/5300-13A, Section 312.
As of May 2017, the International Civil Aviation Organization has been working on developing a harmonized regulation regarding arresting systems.
Research projects completed in Europe have looked into the cost-effectiveness of EMAS. Although arrestor beds have initially been installed at airports where the runway safety areas are below standards, their ability to stop aircraft with minimal or no damage to the air frame and its occupants has proven to bring results far beyond the cost of installations. The latest report, "" shows how the money saved through the first 11 arrestments has reached a calculated total of 1.9 Billion USD, thus saving over $1 B over the estimated cost of development. The study suggests that mitigating the consequences of runway excursions worldwide may turn out to be much more cost-effective than the current focus on reducing the already very low probability of occurrence.

United States installations

The FAA's design criteria for new airports designate Runway Safety Areas to increase the margin of safety if an overrun occurs and to provide additional access room for response vehicles. A United States federal law required that the length of RSA's in airports was to be by the end of 2015, in a response to a runway overrun into a highway at Teterboro Airport in New Jersey. At airports built before these standards were put into effect, the FAA has funded the installation of EMAS at the ends of main runways. The minimum recommended overall length of an EMAS installation is, of which at least is to consist of the frangible material.
, ESCO's EMAS is installed at 112 runway ends at 68 airports in the United States, with plans to install 3 EMAS systems at 2 additional U.S. airports and Runway Safe EMAS is installed at 4 runway ends at 1 airport in the U.S.
The FAA found that pilots are trying to avoid the EMAS and steer to the grass sides in low-energy events in order not to make the news.

Non-U.S. installations

Of the 15 non-U.S. installations, 8 were provided by Zodiac Arresting Systems, 6 were provided by RunwaySafe, 1 in Japan and 1 in Germany.
1 provided by Hankge

FAA-approved manufacturers

, there were three recognized EMAS materials that meet the FAA requirements of Advisory Circular 150-5220-22B, "Engineered Materials Arresting Systems for Aircraft Overruns."
The first, original EMAS was developed in the mid-1990s by Zodiac Arresting Systems as part of a collaboration and technical acceptance by the FAA. EMASMAX® arrestor beds are composed of blocks of lightweight, crushable cellular concrete material, encased in jet blast resistant protection, designed to safely stop airplanes that overshoot runways. Zodiac’s latest, most durable EMAS is installed on over 110 airport runways at over 65 airports on three continents. Zodiac's EMAS has undergone intense testing, including several live aircraft test runs at speeds up and is the world’s first and only EMAS that has safely stopped aircraft in real emergency overrun situations at commercial airports. Zodiac stopped production of EMAS systems as the U.S market slowed down and competition got too hard in the international market.
The Swedish company Runway Safe AB developed an EMAS system, a foamed silica bed made from recycled glass and is contained within a high-strength plastic mesh system anchored to the pavement at the end of the runway. The foamed silica is poured into lanes bounded by the mesh and covered with a poured cement layer and treated with a top coat of sealant.
The third approved material is a patented foam material designed by Zodiac as an alternative to the existing cellular concrete core material.
There is a third manufacturer, certified by the Chinese CAAC, with a product that is very similar to the original one of Zodiac ESCO, but is not FAA approved.

Incidents

Additional media coverage of EMAS statistics, installations, and general news include: