Method for Testing and Evaluating Grassy Runway Surface

The main purpose of this study is to develop a test method to evaluate grassy airfields by determining the mechanical properties that affect airfield performance during takeoff, touchdown, and landing roll. A number of airfields with grassy or partially grassy runways in European Union countries could be more effective for flight operations with better knowledge of the surfaces and their impact on field performance. The proposed method could provide this information. The concept of the method (and an advantage over the existing methods) is to determine 1) wheel-surface braking friction, 2) rolling resistance, and 3) surface roughness. All these parameters are essential for wheel-soil interactions and performance of an airplane on the airfield. Friction coefficients would be determined with a portable tester, which has been designed and built. The complete test method will also include procedures, instructions, and comparison charts. The plan is to present the complete test method for certification so it may be used widely by the general aviation community.