A flight log was a record of where and when a spacecraft had travelled.
TARDISes had flight logs which, according to the Eighth Doctor, never lied. He looked at the flight log for Caleera's TARDIS and confirmed that it had been at the Voord homeworld when it was destroyed. (AUDIO: Scenes From Her Life)
The Tenth Doctor examined the flight logs of Valhalla, and determined that it had crash-landed on Lindis twenty years prior to his arrival. (COMIC: Space Vikings!)