Maximum takeoff weight

Takeoff weight components

The maximum takeoff weight (MTOW) or maximum gross takeoff weight (MGTOW) or maximum takeoff mass (MTOM) of an aircraft is the maximum weight at which the pilot is allowed to attempt to take off, due to structural or other limits. The analogous term for rockets is gross lift-off mass, or GLOW. MTOW is usually specified in units of kilograms or pounds.

MTOW is the heaviest weight at which the aircraft has been shown to meet all the airworthiness requirements applicable to it. MTOW of an aircraft is fixed, and does not vary with altitude or air temperature or the length of the runway to be used for takeoff or landing. A different weight the "maximum permissible takeoff weight", or "regulated takeoff weight", varies according to flap setting, altitude, air temperature, length of runway and other factors. It is different from one takeoff to the next, but can never be higher than the MTOW.

Certification standards

Certification standards applicable to the airworthiness of an aircraft contain many requirements. Some of these requirements can only be met by specifying a maximum weight for the aircraft, and demonstrating that the aircraft can meet the requirement at all weights up to, and including, the specified maximum. These requirements include:

  • structural requirements – to ensure the aircraft structure is capable of withstanding all the loads likely to be imposed on it during maneuvering by the pilot, and gusts experienced in turbulent atmospheric conditions.
  • performance requirements – to ensure the aircraft is capable of climbing at an adequate gradient with all its engines operating; also with one engine inoperative.

At the MTOW, all aircraft of a type and model must be capable of complying with all these certification requirements.