What is Airbus A320 zero fuel weight and how is it used?
Airbus A320 zero fuel weight (ZFW) is the aircraft’s loaded weight without usable fuel: the dry operating aircraft plus passengers, baggage and cargo. In flight simulation and real-world flying, load the payload first, obtain ZFW and ZFWCG, then enter both in the MCDU before checking take-off performance and fuel predictions.
What does A320 zero fuel weight include?
A320 ZFW equals dry operating weight plus traffic load, and it excludes usable fuel. The basic calculation is ZFW = dry operating weight + payload.
Dry operating weight normally includes the aircraft, crew, catering, operating equipment, fluids and unusable fuel according to the operator or simulator model. Payload then adds passengers, checked baggage and cargo. Basic simulators may label the first figure empty weight rather than dry operating weight, so check whether crew and cabin equipment have already been included.
| Weight | Typical calculation | What it represents |
|---|---|---|
| ZFW | Dry operating weight + payload | Loaded aircraft without usable fuel |
| Ramp weight | ZFW + block fuel | Aircraft at the stand before taxi fuel is used |
| Take-off weight | Ramp weight − taxi fuel | Expected weight at take-off |
| Landing weight | ZFW + usable fuel remaining | Expected weight at touchdown |
Why can ZFW be over the limit when take-off weight is not?
Maximum zero fuel weight (MZFW) is a structural limit separate from maximum take-off weight. The precise limit depends on the A320 variant and weight certification represented by the add-on, so use its loading page or documentation rather than a generic figure.
If ZFW exceeds MZFW, remove passengers, baggage or cargo. Reducing fuel cannot correct an excessive ZFW because usable fuel is not part of that number. Conversely, an acceptable ZFW can still produce an excessive ramp or take-off weight after fuel is added.
How do you enter ZFW and ZFWCG in the A320 MCDU?
Load the aircraft first, then enter the resulting ZFW and ZFWCG on the MCDU INIT B or equivalent fuel-prediction page. The exact automation differs between A320 add-ons, but the underlying sequence is the same.
- Select the correct aircraft configuration. Confirm the A320 variant, engine option and cabin layout before loading it. Different models can have different operating weights and certified limits.
- Load passengers and cargo. Use the aircraft’s EFB, load manager or simulator payload screen, then allow any simulated boarding or loading process to finish.
- Record the actual ZFW and ZFWCG. Take these from the completed load sheet or aircraft loading page. If only component weights are available, add the model’s dry operating weight and payload.
- Check the limits. Verify that ZFW is below MZFW and that ZFWCG remains inside the permitted envelope. Repositioning payload changes the centre of gravity but does not change total ZFW.
- Enter ZFW/ZFWCG. On INIT B, the entry commonly uses weight followed by centre of gravity, such as
60.5/27.0. This is an illustrative format, not a recommended loading value. Airbus MCDUs commonly show weight in tonnes and CG as percent mean aerodynamic chord, but always follow the units displayed by the simulated aircraft. Our detailed MCDU data-entry sequence shows where these figures fit among the other INIT and fuel entries. - Enter block fuel separately. Never add block fuel to ZFW. Once both figures are present, the FMGS can derive gross weight and produce meaningful fuel predictions.
- Cross-check the result. Ramp weight should be close to ZFW plus block fuel, while take-off weight should be slightly lower after planned taxi burn. If payload changes later, update the MCDU and repeat the performance calculation. The complete A320 simulator workflow shows this weight entry in context.
Some add-ons transfer loading data from the EFB automatically. Accepting an automatic transfer does not remove the need to compare the MCDU figures with the final load sheet. Complete INIT B before engine start where possible; some implementations replace or restrict that page after the preflight phase.
What is ZFWCG, and is it the take-off trim setting?
ZFWCG is the aircraft’s centre of gravity at zero fuel weight, expressed as a percentage of mean aerodynamic chord. It describes where the loaded aircraft balances before usable fuel is considered.
A value such as 27.0 means 27% MAC, not 0.27 and not a weight. The FMGS combines ZFWCG with the fuel quantity and its distribution to estimate the aircraft’s gross centre of gravity.
Do not copy ZFWCG directly into the take-off trim field. Fuel distribution means take-off CG can differ from ZFWCG, and the required stabiliser setting comes from the aircraft’s load sheet or performance tool. Use the displayed take-off CG and trim result where the add-on provides them.
What causes ZFW mismatches in a flight simulator?
Most ZFW errors come from using planned data that does not match the aircraft actually loaded in the simulator. These are the common failure modes we see:
- Entering gross or ramp weight as ZFW: the MCDU then adds fuel again, producing an implausibly high total weight.
- Mixing units: kilograms, tonnes and pounds are not interchangeable. Convert only when the MCDU display requires it.
- Using a planned ZFW without matching the payload: adjust the simulator’s passenger, baggage and cargo load until the model agrees with the plan. Do not force the planned number into the MCDU while the simulated aircraft has a different actual weight.
- Changing payload after MCDU entry: reload or resynchronise the aircraft, then re-enter ZFW/ZFWCG and recalculate take-off performance.
- Using another A320 variant’s figures: operating weight, cabin configuration, MZFW and CG envelope can differ between A320ceo, A320neo and individual add-on configurations.
- Treating a CG problem as a weight problem: if ZFW is legal but ZFWCG is outside the envelope, redistribute passengers or cargo rather than merely reducing fuel.
Does zero fuel weight change as fuel burns?
ZFW normally remains constant throughout the flight because burning fuel reduces gross weight, not zero fuel weight. It changes only if the aircraft’s payload or operating contents change.
Predicted landing weight is therefore approximately ZFW + predicted landing fuel. If that result exceeds maximum landing weight, burning fuel can lower landing weight but still cannot lower ZFW. Our A320 landing-distance calculation method explains how predicted landing weight then feeds into the runway check.