Compressibility error becomes significant at altitudes above and at airspeeds greater than . Compared to airliners, sailplanes fly at low airspeeds. In 2003 Service Bulletin 315-64/2 reduced the maximum admissible airspeeds and prohibited aerobatic flight. CH-47 Chinook failed when the Roton began to oscillate at airspeeds above . Induced drag is most significant at low airspeeds. It shows how much load factor can be safely achieved at different airspeeds. In most circumstances this equilibrium can occur at a range of airspeeds.