Airspace

Airspace referred to territory within the sky.

In 1997, the Torchwood Institute shot a Jathaa sunglider down. Ten years later, Yvonne Hartman claimed to the Tenth Doctor that the alien spacecraft had "violated [their] airspace." (TV: Army of Ghosts)

In March 2006, all flights in North American airspace were grounded until further notice following the crash landing of an alien spacecraft in the River Thames in London. (TV: Aliens of London)

During the Year That Never Was, 24 hours prior to Launch Day, the aircraft carrier Valiant entered the airspace of Zone One. (TV: Last of the Time Lords)

On 1 January 2019, the Thirteenth Doctor noted that a Dalek reconnaissance scout was flying through Earth airspace, making it a priority for her and Team TARDIS to stop it before human forces could engage it. (TV: Resolution)