C-130 Hercules
From Tardis Wiki, the free Doctor Who reference
The C-130 Hercules was a type of military transport aircraft.
UNIT had a command centre in the cargo hold of an EC-130H Hercules military transport aircraft and could use the plane itself as a mobile base. (TV: The Invasion)
According to The UNIT Dossier written by James Stevens for the Daily Chronicle in January 1970, which was pulled from publication at the eleventh hour, UNIT had yet to acquire a permanent headquarters at this time. (PROSE: Who Killed Kennedy)