Optimizing Low Density Concrete Behavior for Soft Ground Arrestor Systems

Abstract

There are approximately 10 aircraft overruns per year that occur within the United States. Overruns are more common during landing than during takeoff and more likely to occur in wet conditions. Aircraft overruns can result in passenger fatalities, injuries, and extensive aircraft damage. The majority of aircrafts involved in an overrun stop within 305 m (1000-ft.) of the runway threshold. To reduce overrun hazards, the Federal Aviation Administration (FAA) requires airports to have a 305 m (1000 ft) runway safety area beyond the design runway length. However, many airports are restricted from extending their runway because of either natural or man-made barriers. As an alternative to creating a 305 m (1000-ft) runway safety area through runway extension, the FAA allows for the installation of an engineered material arrestor system (EMAS). Arrestor systems are designed as passive systems to reduce aircraft stopping distance by inducing drag forces on aircraft landing gear. An EMAS is typically constructed using a low-density cementitious material. Previous work by the authors has studied the sensitivity of aircraft stopping distance to aircraft characteristics considering two types of arrestor bed materials: phenolic foam and low-density concrete. This article investigates a much larger suite of possible low-density concrete mixes. Three arrestor bed configurations along with twenty-six low-density concrete mixtures were studied to evaluate aircraft stopping distance behavior as a function of low-density concrete mixture. Two aircrafts were considered, B727 and B747. The aircrafts represent different landing gear configurations and weights. Stopping distance was determined for each low-density concrete material considering each aircraft with and without reverse thrust. Over four hundred stopping distance analyses were conducted during the study using the FAA ARRESTOR computer code. In this paper, plots are used to summarize the study results.