Hayter

Professor Hayter was a passenger on the Concorde designated Golf Victor Foxtrot, or British Airways flight 192, in 1982 when it was taken into the past by.

Because his field of study at the University of Darlington was hypnosis, he was able to successfully contra-suggest and therefore resist being hypnotised by the Master. Even so, he did not believe that he had gone back in time. He later sacrificed himself to enable the Xeraphin to communicate with the Fifth Doctor and was absorbed by the Xeraphin life force. (TV: Time-Flight)

Behind the Scenes
Bernard Archard, Geoffrey Bayldon, John Carson, Peter Cushing, Maurice Denham, Michael Gough and William Lucas were considered for the role before Nigel Stock was cast.