Zero-fuel Weight

Zero-fuel Weight

The zero fuel weight (ZFW) of an aircraft is the total weight of the airplane and all its contents, minus the total weight of the fuel on board.

For example, if an aircraft is flying at a weight of 5,000 lb and the weight of fuel on board is 500 lb, the ZFW is 4,500 lb. Some time later, after 100 lb of fuel has been used, the total weight of the airplane is 4,900 lb, the weight of fuel is 400 lb, and the ZFW is unchanged at 4,500 lb.

As a flight progresses and fuel is consumed, the total weight of the airplane reduces, but the ZFW remains constant (unless some part of the load, such as parachutists or stores, is jettisoned in flight).

For many types of airplane, the airworthiness limitations include a maximum zero fuel weight.