Boundary-layer stability analysis is performed by computational fluid dynamic simulation of experiments conducted in the National Aeronautics and Space Administration Langley Research Center 20-in. Mach 6 Air Tunnel in support of the first flight of the Hypersonic International Flight Research Experimentation program. From the laminar computational flow solutions, disturbances are calculated using the linear parabolized stability equations to obtain integrated disturbance growth rates. Comparisons are made between the experimentally observed transition locations and the results of the stability analysis. The stability results from the NASA Langley Research Center Air Tunnel are combined with previous work done for the Calspan University at Buffalo Research Center Large-Energy National Shock Tunnel to show excellent correlation between predicted and observed boundary-layer transition locations. Roughness calculations are also performed and a Reynolds number based on trip height is tabulated with experimental results.