Click and drag thumb button on control bar to study movie. How the rubber meets the runway. One of the centers for such work is the Aircraft Landing Dynamics Facility at NASA's Langley Research Center in Hampton, Virginia. Here, a team of engineers tests the performance of gear struts, tires, and brake systems on military, commercial and research aircraft, including the space shuttle. Propelled by a high-pressure water jet, the carriage, which looks like the kind of modern art sculpture you see in front of government buildings, is capable of reaching a speed of 265 mph and an acceleration of 20 Gs on its short trip down the track.
Engineers can even douse the test surface with water to simulate a rain-slick runway.
The carriage can capture 28 channels of data, such as cornering and friction loads from the tire or strut being tested, and the carriage itself is arrayed with hundreds of strain gauges that tell its operators if their apparatus is about to turn itself into a pile of water-propelled scrap metal. The researchers are primarily interested in the interrelated effects of different runway surfaces, landing conditions, and tire types. In recent years, tests have been conducted on surfaces made from paver blocks, which can be used to make a taxiway that fits together like a tile floor and can be easily repaired. Another innovation, the grooved runway surface, which channels water away, was developed and tested at ALDF and is now in use worldwide. Using the carriage, ALDF engineers have been able to predict tire wear under given steering stresses and crosswind loads.