Sometimes you wonder how wide the safety margins really are.The MMO may be .88 on the 154 but I know they've been flown much, much faster in the old days when the Soviets disposed of jet fuel as they wished.Ask people who've been aboard during the period and had the pleasure of visiting the cockpit (or photographing it, as was the case with the fellow I was talking to) - you will hear mach numbers much higher than you would expect!The CX could also go 'much much faster' as it was designed to do so and its engines are heavily derated.Officially, the fastest subsonic airliner is the Convair 880 (which outpaced even the 990 which was designed to go even faster).

I don`t know the numbers but wasn`t the Convair 880 a speed freak in its day? At the time it knocked the 707 / DC-8 / DH Comet competition into the dust. Unfortunately it was very thirsty and surprise surprise, the accountants won out! On the subject of accountants, any one care to bet on whether the much touted R&R facilities promised on the A380 will enter service? Faced with the option of a gym or a another 30 y class seats, I think I know what`ll happen! CheersJames