This glossary is written for virtual airline and flight simulation use within Virtual Air Canada Airline. It is not intended as a real-world aviation reference.
MTOW
Maximum Take-Off Weight
Maximum Take-Off Weight is the maximum certified gross weight at which an aircraft is permitted to begin the takeoff roll, as defined by the aircraft manufacturer and approved by the regulatory authority in the Aircraft Flight Manual. MTOW represents the highest structural and aerodynamic load the aircraft is designed to sustain during the takeoff phase, which subjects the airframe to the greatest stresses of normal operations. It encompasses the weight of the aircraft structure, engines, fuel, crew, passengers, cargo, and any other items on board at the moment of brake release.
In practice, the actual take-off weight for a given flight may be limited to well below MTOW by performance constraints such as runway length, obstacle clearance gradients, brake energy limits, tire speed ratings, or climb gradient requirements with an engine inoperative. The most restrictive of these performance limits determines the actual allowable take-off weight, often called the performance-limited take-off weight. At high-altitude or hot-and-high airports, the allowable take-off weight can be significantly below MTOW due to reduced air density and its effect on engine thrust and aerodynamic lift. Dispatchers and performance engineers calculate the field-length limited and obstacle-limited take-off weights for every departure to confirm that MTOW is not the binding constraint.