Numerical models used to simulate the lofting mechanisms of runway stones were developed to assess the threat to aircraft structures from runway debris impacts. An inflated aircraft tire model, which was validated by comparison with experimental indentation tests, showed that over-rolling of stones under typical takeoff conditions led to only modest vertical loft velocities of less than 5 m/s. Experiments using a drop weight impactor to simulate a section of aircraft tire descending upon stones, demonstrated that lofting was achieved with impacts with low rubber thicknesses, but with greater rubber thickness lofting was suppressed. Using more realistic tire geometries resulted in launches with backspin, but only horizontally along the ground in the direction of the tire axis. The speed at which launches occurred was proportional to the rate of descent of the tire section and would consequently determine the loft speeds due to potential asperity lofting. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc.