Flight length

"Long Haul" redirects here. For other uses, see The Long Haul.

In aviation, the flight length is defined as the time airborne during a flight. There are four categories: short-haul, medium-haul, long-haul and ultra long-haul.

Short-haul flight: Under 3 hours
Medium-haul flight: 3 to 6 hours
Long-haul flight: 6 to 12 hours
Ultra long-haul flight: Over 12 hours

Distinctions

Absolute distance versus flight length

Airline routes between San Francisco and Tokyo following the most direct great circle (top) westward, and following a longer-distance jet stream route (bottom) when heading eastward

The absolute distance between two points is the great-circle distance, which is always the shortest geographical route. In the example (right), the aircraft travelling westward from North America to Japan is following a great-circle route extending northward towards the Arctic region. The apparent curve of the route is a result of distortion when plotted onto a conventional map projection and makes the route appear to be longer than it really is. Stretching a string between North America and Japan on a globe will demonstrate why this really is the shortest route despite appearances.
The actual flight length is the length of the track flown across the ground in practice, which is usually longer than the ideal great-circle and is influenced by a number of factors such as the need to avoid bad weather, wind direction and speed, fuel economy, navigational restrictions and other requirements. In the example, easterly flights from Japan to North America are shown taking a longer, more southerly, route than the shorter great-circle; this is to take advantage of the favourable jet stream, a fast, high-altitude tail-wind, that assists the aircraft along its ground track saving more time and fuel than the geographically shortest route.

Air time versus schedule times

Air time is the elapsed time that the aircraft is airborne, regardless of what time-zone the flight began and ended in.
Schedule time is the difference between the scheduled local time at the origin and the scheduled local time at the destination and usually differs from the actual time in the air as it is affected by the local time zones. Local clock time flying westward, or "chasing the sun", is slowed, [1] while local clock time flying eastbound is speeded up. However, flights over the International Date Line located at approximately 180o E in the Pacific will subtract 24 hours from the schedule time going eastwards and add 24 hours going westwards. For example, the eastward flight shown in the example from Japan to North America will have a scheduled time of arrival earlier than the departure time, while from North America to Japan the flight will take a whole day longer by local time; the actual flying time in both cases being the same or similar.
The flight classification as long, medium or short haul is classified according to the elapsed air time not the scheduled time difference.