The maximum zero fuel weight (MZFW) is a crucial parameter in aviation that defines the maximum permissible weight of an aircraft without usable fuel on board. This weight limit is of great importance as it ensures that the aircraft is operated within its structural load limits.
What MZFW contains
This includes the weight of the aircraft itself, including all permanently installed systems, crew and operating fluids, but excluding fuel.
The payload consists of passengers, baggage and cargo. These are the variable weights that the aircraft can carry, depending on the specific flight mission.
What MZFW excludes
This includes any fuel available for propulsion consumption and stored in the wing tanks. Fuel is not included in the MZFW calculation as it is consumed during flight and therefore reduces the structural load on the aircraft.
Purpose of the MZFW
Structural boundary
The MZFW is a limit defined by the aircraft manufacturer and certified by aviation authorities such as the FAA (Federal Aviation Administration) or EASA (European Union Aviation Safety Agency). It serves to ensure the structural integrity of the aircraft.
Protection of the aircraft structure
An important aspect of the MZFW is the protection of the wing root and fuselage from excessive bending loads. If there is no compensating fuel in the wings, a high payload can lead to structural damage.
Safety and airworthiness
Compliance with the MZFW is crucial to ensure the safety and airworthiness of the aircraft. Exceeding this weight limit can compromise structural integrity and lead to dangerous situations.
Example for commercial aircraft
Type of weight | Example value |
---|---|
OEW | 90,000 kg |
Maximum payload | 30,000 kg |
MZFW | 120,000 kg |
In this example, the maximum zero fuel weight is 120,000 kg. If the payload pushes the ZFW above this value, the aircraft must either unload cargo or reduce the operational empty weight to comply with the MZFW limit. This ensures that the aircraft is operated safely and within its structural limits.