"Service take-off" is an aviation term, which means that passenger planes begin to provide various services during flight, such as catering, entertainment, seat adjustment and so on. The service takes off about 20 minutes after the flight takes off, and the airline crew will begin to provide the service. When the plane takes off, in order to ensure flight safety, the crew will ask the passengers to turn off the electronic equipment some time ago and adjust the seats to the vertical position. Once the plane climbs to the flight altitude, the crew can start to provide various services for passengers, so that passengers can spend the whole flight in a comfortable environment. Service departure will vary according to flight duration, time, route and airline. For example, long-haul international flights will provide more services, and short-haul flights will provide basic drinks and sweets.