Floor capacity: the weight per square meter of floor in the cargo compartment of an aircraft.

Floor load = cargo weight/underside contact area

Cargo plane: main compartment, lower compartment all loading;

All passenger aircraft: cargo only in lower compartment;

Passenger and cargo mixing machine: main compartment rear and lower compartment carrying goods.

Narrow body jet

Wide-body jet     Mixing machine for passenger and cargo         all cargo carrier

Aircraft cabin structure

In general, aircraft are divided into main cabin and lower cabin.But B747 has upper, main and lower compartments.

The FORE HOLD and AFTER HOLD are typically located in the underbelly of an aircraft, and are typically divided into several FORE HOLD units.

1. Narrow-body aircraft

The lower hold is used only for carrying bulk cargo, which is commonly referred to as "bulk hold".

2. Wide-body aircraft

The main lower hold is mainly used for loading containerized cargo, so it is also called the consolidated cargo compartment.Bulkcargo holds are also provided in the lower decks of most wide-body aircraft.