Soft-Ground Aircraft Arresting Systems.

The soft-ground aircraft arresting system study was initiated to determine whether or not aircraft having gross weight of 114,000 pounds to 630,000 pounds could be safely stopped after overrunning the available length of runway. The extended length of runway was limited to 1000 feet and the maximum velocity of the overrunning aircraft was selected to be 70 knots. The system was to be completely passive, have a long life, and easily repaired and maintained. Several arrestor materials such as clay, sand, gravel, water, an plastic foam were considered. An aircraft wheelarrestor material model was developed and incorporated into a computer program FITER which allowed the determination of the aircraft stopping distance, landing gear loads, dynamic response, and rut depth in the arrestor material. Analyses conducted showed that sand, clay and water systems were not suitable arresting materials. Aircraft arrestment simulations were conducted for gravel and plastic foam arrestors and it was found that all aircraft could be safely stopped in less than 1000 feet. Evaluation of the stopping distance in an arrestor bed with the stopping distance of an extended runway was made and it was found that the arrestor system was needed to assure the safe stopping of an aircraft. Initial arrestor bed configurations were developed along with installation methods and attachment of the arrestor to the extended runway surface. Keywords Aircraft arrestor, Foam arrestor, Soft-ground arrestor, Aircraft decelerator.