Why, my boyfriend asked me as I picked him up from the airport this weekend after a flight from Los Angeles to Paris, did my flight take off an hour late but still arrive early?
The answer is, like many things in aviation, complex — and, in this case, the answer is also “complexity”. It takes a huge variety of systems working together to get your flight from A to B, and sometimes those don’t work together as planned.
Flights are delayed for a wide variety of reasons. Incoming aircraft can be late, something may take longer than expected when preparing the plane for its next flight, the airport may be busy, there may be weather en route, the winds may be stronger than expected, your flight may be held because there is congestion at your destination, or something else entirely.
When airlines plan their schedules, they make sure to take all of these things into account. Frequently, they’ll pad their schedules with extra time: whether fleetwide, on specific routes, at certain times of year, or to make sure that their slower planes can operate the flight as a backup.
So, a flight that might — in perfect conditions, with a following tailwind, and no congestion — take just nine hours might be scheduled as ten instead.
It’s all part of the giant dance of scheduling aircraft, which airlines do very carefully. They’re especially careful if they’re a European airline or flying from Europe, since the delay payment scheme in Flight Compensation Regulation EU261/2004 applies based on your scheduled arrival time.
If you think that’s a bit of an incentive for an airline to book two-hour flights as three-hour flights, you’re not wrong. But the pressure on the other side is that airplanes don’t make airlines any money if they’re sitting on the ground. So the airline has an incentive to schedule as tightly as possible, especially on short haul flights of four hours or less.
Moreover, airlines know that passengers want to arrive on time, that governments produce official rankings from their data, and that if they’re too delayed, too often, they’ll get a reputation among the flying public.
In recent years, too, in addition to schedule padding, airlines have developed several new options at their disposal to make up time.
The first is the most obvious and isn’t exactly new: the pilot can step on it, burning a little extra aviation fuel to fly a little faster. With increasingly connected air traffic control systems, alongside live location-based tracking, this kind of request becomes easier to fulfil.
Less obvious are some of the tricks used by modern, high-tech connecting hubs like Helsinki and Reykjavik. Finnair, for example, used its ticket data to figure out which inbound flights have the tightest connections and prioritises them in the landing queue and arrivals. Do some of those connections from the Delhi flight look a bit dicey? Well, get the pilot to step on it and move that plane a couple of slots ahead in the queue.
All of which is to say: if you’re meeting an overnight flight that arrives in the early morning, and you see it’s departed an hour late before you go to sleep, don’t think you can spend an extra hour in bed. It might just be on time.