Why a Delayed Flight Can Still Arrive “On Time”
An airline’s published flight time is not simply the minutes an aircraft is expected to spend in the air. It usually runs from the moment the plane leaves the gate at one airport to the moment it reaches the gate at the other. That clock includes taxiing—and the schedule may include extra time beyond the airline’s best estimate of a routine trip.
This built-in cushion is often called schedule padding. It gives a flight room to absorb predictable snags such as a long taxi queue, a busy arrival airport, or a headwind without pushing its arrival past the scheduled time. The cushion can also make an airline’s on-time figures look better: if a plane leaves late but uses less than all the time allowed, it may still reach the gate within the window used to count arrivals as on time.
The tradeoff behind the buffer
Padding is not necessarily just a trick. Flight times vary, and schedules need to work across ordinary disruptions that cannot be predicted precisely for each departure. But the buffer has costs: a longer published journey can make travel appear slower, and extra scheduled time can leave aircraft and crews waiting before their next assignments. Airlines therefore balance a more achievable schedule against efficient use of planes and people.
The distinction matters because an on-time arrival does not mean a flight departed on schedule—or that its trip took only as long as the aircraft needed under ideal conditions. A passenger comparing airlines may see one carrier report better punctuality partly because its timetable leaves more room for delays. The schedule itself helps determine what “on time” means.
