27 February 1946: birth of Tom Chadbon, who played Duggan in City of Death (1979) and Merdeen in The Mysterious Planet (1986), and also various Big Finish roles including Harry Sullivan's younger brother Will in the second Sarah Jane Smith series.
27 February 1976: birth of Nikki Amuka-Bird, who played Keryehla Janees, aka Beth Halloran, one of the Sleepers in the 2008 Torchwood episode Sleeper, and Helen Clay / the Glass Woman in Twice Upon a Time (Twelfth Doctor with First Doctor, 2017).
ii) broadcast anniversaries
27 February 1965: broadcast of "Escape to Danger", third episode of the story we now call The Web Planet. Ian escapes and joins with Vrestin of the Menoptera; the Aniums forces the Doctor to help it.
27 February 1971: broadcast of fifth part of The Mind of Evil. The Master and the Doctor together try to subdue the Keller Machine, and UNIT raids the prison to retake the missile.
27 February 2009: broadcast of A Day in the Death (Torchwood), the one with undead Owen and Richard Briers as the dying guy with the alien device.