How Fast an Aircraft Turns When It Has To

Summary

When the schedule gave an aircraft 90 minutes to 3 hours on the ground and it landed 30 or more minutes late, the median time at the gate was 66 minutes, against 123 scheduled. Measured on 1,859,692 departures after a late landing, from the tail number on each flight.

The DOT file names the aircraft that flew each flight and records when each flight reached its gate and left it. For a flight whose aircraft’s previous flight is known, the minutes between the aircraft reaching the gate and leaving it are the scheduled turn plus the flight’s departure delay minus the previous flight’s arrival delay. 19,440,732 departures have such a flight, and 1,859,692 of them (9.6%) followed an aircraft that landed 30 or more minutes late. The schedule says how long the aircraft should have had. The records say how long it took.

Minutes between the aircraft reaching the gate and leaving it, for departures whose aircraft’s previous flight is known. A dash is a cell under 120 turns.

When the schedule gave an aircraft 90 minutes to 3 hours and it landed 30 or more minutes late, the median time at the gate was 66 minutes, against a scheduled average of 123 (255,023 turns). 93.3% of those aircraft left within the scheduled time, and the fastest tenth were gone in 42 minutes or less. An aircraft that landed on time or early on the same schedule spent a median of 122 minutes there. The median late aircraft was turned in 46% less time than the schedule averaged, 57 minutes under it. With 3 to 6 hours scheduled the median was 172 minutes after a late landing and 301 after an on-time one. At the other end, with 30 to 44 minutes scheduled, the median was 38 minutes after a late landing against 37 scheduled, and 47.6% of those turns were within the schedule.

An aircraft that landed on time or early did not turn faster than it was scheduled to. On the 90 minutes to 3 hours band the median was 122 minutes at the gate against a scheduled average of 117. Aircraft that landed early are in this group, and they wait for their departure time. The same schedule took 66 minutes when the aircraft was late and 122 when it was not, which shows how much of the scheduled ground time was needed on the days it was needed. It does not say how much a crew or a gate would need on any one day.

Departures whose aircraft landed 30 or more minutes late and whose schedule gave it 60 minutes to 3 hours on the ground. The gap compares each full-period airline’s share turned in 45 minutes or less with the other full-period airlines pooled. Airlines that did not report every month are shown with their months and are not compared.

Among the 12 airlines that reported every month, the share of late-aircraft turns finished in 45 minutes or less runs from 3.5% at Alaska Airlines to 64.7% at Republic Airways, on schedules of 60 minutes to 3 hours. Republic Airways, SkyWest Airlines, PSA Airlines and Envoy Air finished more of them that quickly than the other airlines together (+47.0 points at Republic Airways). Delta Air Lines, Alaska Airlines, JetBlue and American Airlines finished fewer (-17.9 points at Delta Air Lines). Each of the 4 regional carriers finished a larger share that quickly than any mainline or low-cost airline: together they finished 59.2% of 140,549 such turns in 45 minutes or less, the others 9.6% of 592,679. The records do not say what aircraft flew, how full it was or what had to be done to it, so the gap is between the flights each airline operated and does not say how well one is run. Endeavor Air, Hawaiian Airlines and Spirit Airlines did not report every month, so they are listed with the months reported and left out of the comparison.

Across the 60 covered airports with at least 500 such turns, the median time at the gate for a late aircraft on a 60 minutes to 3 hours schedule runs from 48 minutes at DCA to 75 at HNL, with a median of 57 minutes across airports. The airlines at an airport are not the airlines at any other, so this describes the turns done at that airport and does not rate it.

The data holds no aircraft type, passenger count, crew schedule or gate, so it cannot say why one carrier turns an aircraft faster than another. A flight an airline cancelled never left and is not in any figure, so this describes the aircraft that did go on to fly. The DOT records the tail number of the aircraft that flew each flight, so a flight covered by a substitute aircraft is matched to the aircraft that flew it. The delays are gate times, so the time on the ground is the time at the gate, from the aircraft arriving to the aircraft pushing back, and includes any wait at the gate for a departure time. A link is dropped when the previous flight is unknown, diverted or has no arrival time, when two flights of one aircraft share a scheduled minute, when the schedule puts this flight out before the inbound is due in, and when the reported times put the inbound at the gate after this flight had left. Aircraft that sat more than twelve hours are not turns and are left out.