Recirc Fan?
777 into Heathrow last year, smoke and strong odor by cabin crew and pax during descent, got recirc fan EICAS on short final (clear day, emergency vector provided)...very uncomfortable symptoms, but ultimately was a lower recirculating fan....insidious onset with rapidly excalating intensity as cabin differential reduced in descent. Had we gotten EICAS msg earlier, we would have felt better doing that procedure and waiting for smoke/odor to abate...either way, we were heading straight for the runway (27L with two minute taxi to one of the old J-gates, which we elected to do with LHR Fire Chief concurrence). Recirc Fans having been off for approx. 10 minutes, there were no cabin indications upon opening main doors. Maintenance found the failed fan. Same model 777-200B, same airline.