Flight length

In aviation, the flight length or flight distance refers to the distance of a flight. Aircraft do not necessarily follow the great-circle distance, but may opt for a longer route due to weather, traffic, to utilise a jet stream, or to refuel. Commercial flights are often categorized into long-, medium- or short-haul by commercial airlines based on flight length, although there is no international standard definition. The related term flight time is defined by ICAO (International Civil Aviation Organization) as "The total time from the moment an aeroplane first moves for the purpose of taking off until the moment it finally comes to rest at the end of the flight", and is referred to colloquially as "blocks to blocks" or "chocks to chocks" time. In commercial aviation, this means the time from pushing back at the departure gate to arriving at the destination gate. Flight time is measured in hours and minutes as it is independent of geographic distance travelled. Flight time can be affected by many things such as wind, traffic, taxiing time, and aircraft used. A flight's length can also be described using the aviation term of "Flight Haul Type", such as "short-haul" or "long-haul". Flight haul types can be defined using either flight distance or flight time. David W. Wragg classifies air services as medium-haul being between ; short-haul asbeing shorter and long-haul as being longer. David Crocker defines short-haul flights as shorter than , and long-haul as the opposite. Hong Kong International Airport considers destinations in North and South Americas, Europe, the Middle East, Africa, Southwest Pacific and the Indian Subcontinent long-haul and all others are short-haul. Japan Air Lines defines routes to Europe and North America as long-haul and all other flights as short-haul. Qatar Airways defines all flights from Qatar to the Americas, Australia, and New Zealand as Ultra-long-haul, and all other flights as medium or long-haul. Virgin Australia defines domestic flights as within Australia, short-haul as those to South East Asia/Pacific and long-haul as those to Abu Dhabi or Los Angeles.