Structural Weights - MZFW, MRW, MTW, MLW

Rickie C. less than a minute

Structural weights are weight limits designated by the AFM (Aircraft Flight Manual) that limits the maximum weight of an aircraft at certain phases of flight. Going over the maximum structural weights at any point can potentially cause fatal or air frame damage. 

It is important for pilots and dispatchers to be aware of all of the aircraft's structural weight and to actively monitor the weights to ensure it does not go over the limit. 

All these of structural weights are NOT static. These numbers can change based on a bunch of factors such as temperature, altitude, slope gradient of runway, runway length, etc. 

§ 121.189 (Takeoff Limitations for Turbine Engines) and §121.195 (Landing Limitations for Turbine Engines) both have similar wording stating that the aircraft can not takeoff or land at their respective airports if the aircraft is over the weight listed in the AFM.

Structural Weights

Maximum Zero Fuel Weight (MZFW)

  • Everything but the fuel

Maximum Ramp Weight (MRW)

  • Zero Fuel Weight + All Fuel (Taxi, Burn, Alternate, Reserve)

Maximum Takeoff Weight (MTW)

  • Ramp Weight - Taxi Fuel

Maximum Landing Weight (MLW)

  • Takeoff Weight - Used Fuel