If you will forgive the thread drift, the name Squadron Leader Ted Sismore prompts me to mention that, in addition to the London-Cape Town record, he was a distinguished wartime navigator.
He was in the lead Mossie that deliberately disrupted a scheduled speech to be broadcast by Herman Goering in 1943.
He was the lead navigator on three Mossie raids in Denmark that attacked Gestapo headquarters.
http://www.freerepublic.com/focus/f-.../1050213/posts
He planned the route for Operation Jericho, the Mossie raid on the Amiens prison .
After the was he crossed over and became a pilot, and later retired as an Air Commodore.