18 hours may be the record for present day aircraft and schedules, but I think the non-stop LAX - Copenhagen SAS schedule on a DC7C in the late fifties was in the region of 21 hours. If I am wrong, then my apologies as I was only a nipper when I had that pleasure. Although my legroom requirements weren't great, I think passenger comfort in those aircraft was good, but the noise was something else!
Cheers.
Niaga Dessip
