Have you ever wondered why does your flight departs at certain time of the day? Do you think there’s a reason why when you take a transatlantic flight, it departs in the morning in Europe or in the afternoon in America? It’s all part of a complex scheme called “Airline scheduling”.
The time a flight departs it’s characterized by a lot of factors, like: aircraft types, gates at the airport of departure and arrival, air traffic control, environmental regulations, crew scheduling, time-zone of airport of arrival, flight demand and so many others not listed. To make things easier, let’s try to explain the concept by taking several examples:
Example: American Airlines flight from Los Angeles to Washington DC
American Airlines (AA) is one of the largest carriers in the US, handling over 200 million passengers a year. One of its hubs is the Los Angeles Airport (LAX), one of the busiest in the world. The route to the country’s capital is quite popular, over 6 flights a day from AA depart towards DC BUT none of them is a direct flight. Why?
It’s all part of the flight scheduling scheme. AA has hubs distributed in strategic places all over the US to allow flights to be scheduled at the best time possible, this is, the time at which more passengers can take the flight. In the case of the flight Los Angeles – Washington DC, a layover may be expected on the central region, as it’s the case of the hub in Dallas-Fort Worth.
How does the Dallas-Forth Worth Airport Works? The principle is quite simple, flights from the west coast arrive at a certain interval of time to the airport, passengers connecting to the east-coast have a layover of not more than 2 hours, to then depart to the east coast. The same principle works the other way around. This strategy allows to have a constant flow of passengers from coast-to-coast with planes with more passengers, than direct flights from different places to the east coast. This is an operation used by big airlines, but it comes with a great disadvantage: there are intervals of time where planes are not departing and planes on the ground do not generate money.
Example: Ryanair flight from Frankfurt Main to London Stansted
Ryanair is a European low-budget airlines, which in comparison to the American Airlines case, it’s totally different. Ryanair only offers direct flights to its destinations and usually to airports outside the cities. In this case, the airline wants to be as little as possible on the ground, so it schedules it’s flights on such a way that the plane is only on the ground to load up new passengers onto a new destination. Therefore, in this case, the organization of arrivals-departures coming from just one place makes no sense.
Example: LATAM flight from Mexico City to Sao Paulo
Long flights that do not cross many times zones pose a logistical challenge to airlines, as in the case of the route of Mexico City to Sao Paulo, where the flight is over 10 hrs non-stop and with a time difference of only 3-hours between both cities. But why is this a problem? If the flight departs Mexico at 16:40 local time, it will arrive at 5:40 of the next day, which is ideal, because it allows the passenger of the flight to connect to other cities from Sao Paulo. But then the flight must go back to Mexico, if leaving in the morning, it would arrive late afternoon, messing up the opportunity for passengers to take further connecting flights (same principle works for transatlantic flights from Europe to America). Therefore, some airlines decide to stay on ground more time, so they could take advantage of more passengers with connecting flights. Also, in this case where planes have to sit around without generating income, airlines have decided to do some maintenance to the aircraft, and thus taking advantage of the situation.
There are many more factors that decide when an aircraft departs, and for this, airlines have developed algorithms to optimize their operation, because let’s remember, airlines always try to maximize revenue!