Development of Deceleration-Based Friction Prediction Models and Methods on Semiprepared Runway Surfaces

Abstract

Both civilian and military airfield managers require the safe operation of aircraft on runway surfaces. This includes the operation of ground traffic on airfield operating surfaces as well as connecting road infrastructure. Often times in austere environments, this road infrastructure is unpaved and consists mostly of either semiprepared or unbound soils. It has been shown in numerous research efforts that surface friction is an excellent indicator of safe operating conditions. Although a great deal of work has been done to quantify safe surface conditions for landing and takeoff operations on rigid and flexible pavement structures, limited research exists to extend such efforts to soil-based or semiprepared surfaces. The objective of this research was to develop deceleration-based surface friction prediction models on unpaved surfaces with varied moisture conditions and soil types. Surface friction, in this study, was quantified using the Findlay Irvine Mk2-D GripTester. Deceleration was measured using four smartphone inertial measurement units (IMUs), one Bowmonk IMU, and one Xsens IMU. Tests were conducted in three ground vehicles: a high-mobility multipurpose wheeled vehicle, a civilian ½-ton pickup truck, and a civilian full-size sport utility vehicle. The various deceleration-based devices tested here adequately correlated (coefficient of determination >0.6) with Mk2-D GripTester measurements collected on unpaved soil runways. The models and measurement methods detailed here are of considerable use to both semiprepared runway and ground vehicle operations managers around the world needing to measure safe surface conditions following inclement weather.