Originally Posted by
Often1
The whole use of the term "padding" is a misnomer.
Air carriers establish their schedules to reasonably account for variables which include any number of factors. This simply means that when things work out, the aircraft is on the gate early. It is entirely appropriate and simply represents a well-educated consideration of factors which often occur.
On any given route, at any given time of day, and with a particular aircraft, any carrier may use a shorter or longer block time.
The issue, at least with DL, is that frequently when planes do arrive early, that there is no gate available, and so pax and crew end up all parked on the tarmac and awaiting for a gate to open. Arriving early is one thing, but deplaning early is quite another; the latter is less frequent than the former. That is, there is consideration in the schedules for variable factors - which is logical, of course (though the extent of it is up for debate), but there seems to be no consideration of that given - that as a result of this, or tailwinds or what not, some flights will arrive early - at the ground gate allocations, at least based on anecdotal evidence.