The maximum takeoff weight of an aircraft refers to the maximum limit of the total weight of the aircraft when the aircraft takes off and runs at the takeoff line with increased horsepower according to structural strength, engine power, braking efficiency and other factors, so it is also called the maximum takeoff total weight. This data is stipulated by the aircraft manufacturer. When determining the maximum authorized takeoff weight of a civil aircraft, it is necessary to meet certain airworthiness standards, which are generally determined under the international standard atmospheric conditions stipulated by ICAO. In practical application, the maximum takeoff weight is also limited by other factors, such as runway length, atmospheric temperature/takeoff plane pressure height and obstacle-crossing ability. The takeoff weight of an aircraft consists of structural weight, power plant weight, fixed equipment weight, fuel weight (including mission fuel and dead oil), crew weight and payload weight. When the maximum takeoff weight is reached, the plane must reach the speed of V 1, even if one engine is stopped, it can take off safely.