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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.
Take-Off Weight is the total weight of the aircraft at the moment of brake release for take-off. It equals the Zero Fuel Weight (ZFW) plus the total fuel on board at the time of departure, including taxi fuel, trip fuel, contingency fuel, and any alternates or reserves. TOW is a critical performance parameter because it directly determines the V-speeds (V1, VR, V2), the required field length, the climb gradient the aircraft can achieve, and the maximum obstacle clearance requirements for the departure. Performance engineers and dispatchers calculate the maximum allowable TOW for each flight based on runway length, elevation, temperature, wind, and obstacle data. TOW must not exceed the aircraft’s Maximum Take-Off Weight (MTOW), which is a structural and certification limit defined in the Aircraft Flight Manual (AFM). In some conditions - particularly on short runways, in high temperatures, or with heavy payloads - the performance-limited TOW may be lower than MTOW. When this occurs, operators may use techniques such as a reduced-thrust (flex) take-off to improve engine margins while still meeting climb performance requirements. Accurate TOW is entered into the FMS before departure to ensure correct V-speed calculations and thrust management.

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In Virtual Airline Operations

SimBrief calculates and displays the estimated TOW for each VACA flight plan, and this figure should be loaded into the aircraft’s FMS or weight and balance page before departure. Many aircraft add-ons include a fuel and payload manager where virtual pilots can enter ZFW and fuel to match the SimBrief plan. Using the correct TOW ensures that V-speeds and performance data are accurate, making the simulated flight as realistic as possible.
  • ZFW - Zero Fuel Weight
  • V1 - Decision Speed
  • VR - Rotation Speed