 It had an enclosed cabin for (in most versions) 12 passengers, along with two crew in an open cockpit, and has the distinction of being the world's first airliner to be designed with an on-board lavatory.The prototype first flew on 4 December 1919, shortly after it was displayed at the 1919 Paris Air Show at Le Bourget.The W.8 was subsequently revised to give the W.8b, W.8e (H.P.26), W.9 (H.P.27) and W.10 (H.P.30).