Definitions
Manufacturer’s Empty Weight (MEW). The weight of the structure, power plant, furnishings, systems, and other items of equipment that are considered an integral part.
Operational Empty Weight (OEW). The MEW plus the operator’s items; i.e. the flight and cabin crew and their baggage, engine oil, unusable fuel, toilet chemicals and fluids, emergency equipment, catering equipments, etc…
Dry Operating Weight (DOW). The total weight of an aircraft ready for a specific type of operation excluding all usable fuel and traffic load.
Zero Fuel Weight (ZFW). The weight of the total traffic load plus the DOW.
Landing Weight (LW). The weight at landing at the destination airport. The ZFW plus the fuel reserves.
Takeoff Weight (TOW). The weight at takeoff at the departure airport. The LW plus the trip fuel, or the ZFW plus the takeoff fuel.
Maximum Structural Weight
Maximum Structural Takeoff Weight (MTOW). The TOW must never exceed a weight which is determined in accordance with in flight structure resistance criteria, resistance of landing gear and structure criteria during a landing impact with a vertical speed equal to 
.
Maximum Structural Landing Weight (MLW). The LW is limited assuming a landing impact with a vertical speed equal to 
.
Maximum Structural Zero Fuel Weight (MZFW). The limit when there is no fuel in the tank.
Maximum Structural Taxi Weight (MTW). This is limited by the stresses on shock absorbers and potential bending of landing gear during turns on the ground.
Minimum Structural Weight
The lowest weight selected by the applicant at which compliance with each structural loading condition and each applicable flight requirement. Usually, the gusts and turbulence loads are among the criteria considered to determine that minimum structural weight.