Betts (The Green Death)

Betts was a UNIT soldier serving under Brigadier Lethbridge-Stewart.

Biography
Betts was part of the convoy sent to Llanfairfach to destroy the giant maggots. (TV: The Green Death)

Behind the scenes

 * David Billa also played UNIT soldiers in The Three Doctors and Invasion of the Dinosaurs. It is unclear whether these are meant to be the same characters.