RELEVANT DISCUSSION: FAA-H-8083-1A AC 120-27E
EMPTY WEIGHT
Empty weight is defined as the total weight of an aircraft including all fixed ballast, unusable fuel, undrainable oil, total quantity of engine coolant and total quantity of hydraulic fluid, and excluding crew, payload, usable fuel and drainable oil.
BASIC OPERATING WEIGHT (BOW)
Total weight of the aircraft, including crew, ready for flight, but without payload or fuel (sometimes excludes the crew). Includes all fixed ballast, unusable fuel, normal operating level of oil and total quantity of hydraulic fluid (transport aircraft only).
FUEL LOAD
Usable fuel only, not the fuel in the lines or trapped in the sumps.
MAXIMUM ALLOWABLE ZERO FUEL WEIGHT (MZFW)
1. The wings flex up and down with turbulence, applying severe bending loads at the wing roots. These loads…