A Viscount does hold the LHR - MME record. Capt Joe Sharps, one Boxing day, howling southerly gale, 09 (10?) departure to a 05 (06?) arrival, direct track. I may be wrong but I think the time was 24mins airborne. No doubt one of my (ex) colleagues will correct me. There were numerous attempts to beat the time but it was never bettered. BMA, sadly missed.