Weight-on-Wheel is a theoretical-experimental R&D project for the use of elements designed to withstand large mechanical loads, bolts of the landing gear of the A-400M cargo plane, as sensors to detect a threshold of support on the ground during the maneuver of landing allowing the use of air brakes without risk of overturning without interfering with its initial function.
The study consisted of two phases, firstly, a theoretical phase, where the geometry of the bolt and the load conditions were studied to determine the appropriate strain gauges and their position in the bolt. Secondly, an experimental phase of verification, where the location of the gluing was optimized with positive results up to maximum load values of 120%
The prototypes, real instrumented bolts, demonstrated their independence in overcoming the loading threshold with respect to the angle of rotation during landing with excellent results in fatigue tests. Based on the prototypes, the technical requirements for the manufacture of the “ground plane” detection system of the Airbus A-400 M freighter that are currently used were developed.