Engineered Material Arresting Systems
When a landing aircraft over runs the end of a runway there can be disastrous results; the aircraft may run into a body of water, busy highway, or nearby residential area.
On February 28, 1984, a Scandinavian Airline System DC-10-30 aircraft overran after landing on runway 4R at John F. Kennedy (JFK) International Airport and plunged into Thurston Basin.
In consideration of the potential for catastrophic overrun accidents, the NTSB issued the following Safety Recommendation A-84-37 which stated, “Initiate research and development activities to establish the feasibility of soft ground aircraft arresting systems and promulgate a design standard, if the systems are found to be practical.”
In response to the recommendation, the FAA in cooperation with Engineered Systems, Co. (ESCO) of Logan Township, NJ undertook an aggressive research effort to develop a solution. Research began with the development of a mathematical model to predict the factors associated with an overrunning aircraft. In 1996, full scale testing was used to successfully validate the model.
The outcome was a viable solution called engineered material arresting system or EMAS. EMAS, as its name implies is an engineered material that deforms readily and reliably under the weight of an overrunning aircraft and the resulting drag forces decelerate the aircraft to a safe stop.
The harsh environment at the end of runways makes EMAS susceptible to destructive forces of jet blast, seasonal climate variations, and wildlife. Consequently, the FAA continues to work with EMAS manufacturers to ensure that the systems maintain adequate durability.
EMAS is now considered a proven technology having been installed at more than 50 locations throughout the United States. EMAS has been effective in safely decelerating seven overrunning aircraft since 1999. In all cases, serious damage to the aircraft was averted and there were no injuries to passengers on board.
The FAA is currently working with other companies to study potential additional alternative materials and systems to enhance runway safety throughout the United States.
The Office of Airport Safety and Standards (AAS-1) issued Advisory Circular 150/5220-22a Engineered Materials Arresting Systems (EMAS) for Aircraft Overruns on 9/30/2005.
In 1995, the FAA developed the software application called ARRESTOR. ARRESTOR was designed to determine the landing gear loads and airframe dynamic response to both soft ground and the runway surface roughness. The application computes the aircraft wheel rut depths during landing and takeoff so that surface rehabilitation maintenance can be estimated, and includes a model for soil deformation that gives fairly accurate levels of soil or asphalt rutting under aircraft wheel loads. ARRESTOR was specifically designed for the DC-9, DC-10, B-707, B-727-100, B-727-200, and B-747 aircraft due to aircraft manufacturer data availability. Engineered Arresting Systems Corporation (ESCO) used ARRESTOR as a foundation to their Engineering Material Arresting System (EMAS) modeling development. ESCO refined, further developed, and evaluated their modeling program to became the first FAA approved EMAS. The ARRESTOR version available for download is the last FAA developed version.