Originally Posted by
ecaarch
As posted earlier, any difference in speed is negligible. The difference in scheduled flight times is more a factor of the time-of-day of each flight and DL padding the schedule to accommodate potential ground delays. @:-)
But presumably potential ground delays at the same airport pair at around the same time (usually these 3x daily flights are only some 1-3 hours apart for all three of them, sometimes only 20-40 min apart each) will be the same, so the time padding is the same for all, the difference is the speed of aircraft flight... so I have also observed.
767s in general make even a short 7h flight seem like an eternity (I mean pre-refurb. 767-300ERs, with their ancient and stuffy cabin, tiny IFE screen in BE only, no IFE elsewhere, etc.), while on an A330 or 747 it seems to pass in an instant.