Are aircraft parabolic flights really parabolic?

摘要

Aircraft parabolic flights provide repetitively short periods of reduced gravity by flying a ballistic trajectory, preceded and followed by periods of acceleration up to 2g. The ballistic part has a shape of an arc of a parabola and is quite commonly referred to as a parabolic flight.In this short note, we want to show that, although the wording parabolic is stricto sensu incorrect, it is though not far from reality and we show how to calculate simply the approximation committed by calling this trajectory parabolic.