The time rotor, sometimes called a time column, was a component in the central column of the TARDIS console. While the TARDIS was in flight, the rotor rose and fell, stopping when the TARDIS reached a destination. It was associated with the 'whooshing' noise heard when the TARDIS was in flight. If the glass protecting the time rotor was damaged, such as when Mels shot it, a poisonous gas would come out of it until the extractor fans were activated. (TV: Let's Kill Hitler)