Lateral balance cone

Lateral balance cones were components of a Type 40 TARDIS.

The Fifth Doctor speculated that an attempt to get Tegan back to Heathrow Airport in 1981 was unsuccessful because of a "temperamental solenoid" in the lateral balance cones, causing the TARDIS to land in the right place, but three centuries too early. (TV: The Visitation)

When the lateral balance cones went offline on another trip, the Fifth Doctor landed in 2008 Hove instead of 1818 Brighton. (AUDIO: Cuddlesome)

Adric denied being responsible for reprogramming the helmic regulator, particularly as the lateral balance cones were already "out of alignment". (AUDIO: The Toy)