How do I calculate A380X take-off performance in MSFS?
Use the official FBW A380 takeoff performance calculator in MSFS and correctly enter V-speeds, FLEX, flap configuration and THS.
For the FlyByWire A380X in Microsoft Flight Simulator 2020 or 2024, use FlyByWire’s official Takeoff Performance Calculator, a separate browser-based tool—not an in-aircraft flyPad/OIS function. Enter final runway, weather, take-off weight and configuration data, then manually copy V-speeds, FLEX and flap/THS output to the FMS; every value must match the aircraft at brake release.
FBW A380 takeoff performance calculator walkthrough
The FBW A380 performance calculator needs the precise departure point, expected runway conditions and actual take-off configuration. Open the official calculator through FlyByWire’s web tools or documentation and select the A380X rather than using an A320 profile or generic A380 figures.
- Finish loading the aircraft. Load payload and fuel before calculating. SimBrief can provide planned figures, but importing a flight plan does not calculate take-off performance; our guide to connecting SimBrief with the A380X explains what the import does and does not supply.
- Enter take-off weight and CG. Use the predicted weight at brake release, normally ramp weight minus expected taxi fuel. Do not enter zero-fuel weight, ramp weight, maximum take-off weight or block fuel in a field labelled TOW. Use the CG type requested by the calculator and take it from the final aircraft loading data; if the underlying ZFW or ZFWCG is wrong, correct that first using our A380X ZFW and ZFWCG procedure.
- Select the airport, runway and runway entry. Choose the runway end actually assigned. For an intersection departure, select that intersection or apply the supported runway-shift entry so the calculation uses the reduced distance. Verify the displayed TORA, TODA or other available-distance data rather than assuming the airport’s published full runway length is being used.
- Enter the weather in the displayed units. Wind direction is the direction from which the wind blows and wind speed is normally entered in knots. Enter outside air temperature in degrees Celsius and QNH in the unit selected by the calculator, usually hPa or inHg. Use the weather represented inside MSFS if it differs from an imported or real-world report.
- Choose the runway state. Select dry, wet or the supported contaminated condition that matches the simulator runway. A dry result must not be reused for a wet runway simply because it produces a higher FLEX temperature.
- Set the take-off configuration. Select the intended flap configuration, pack state and engine anti-ice state. If the calculator offers an optimised configuration, its result is valid only when that configuration is also selected in the cockpit.
- Calculate and inspect the result. Check the runway, entry, weight, configuration and weather shown with the output. V-speeds should follow
V1 ≤ VR ≤ V2. Do not repair an error by changing one speed manually or copying figures from another flight.
The official calculator remains external in both MSFS 2020 and MSFS 2024. The A380X OIS can be used for aircraft loading and other cockpit tasks, but it does not replace this take-off calculation or automatically transfer the result.
Where do V1, VR, V2, FLEX and configuration outputs go?
Transfer the accepted result manually to the A380X FMS take-off performance page on an MFD. Open the FMS PERF section, select the take-off phase and enter each output in its corresponding field.
| Calculator output | A380X action |
|---|---|
| V1 | Enter in the V1 field on the PERF TAKE OFF page. |
| VR | Enter in the VR field. |
| V2 | Enter in the V2 field. |
| FLEX temperature | Enter in FLEX TO TEMP. When the valid result requires TOGA, leave FLEX blank and use the TOGA thrust detent. |
| Flap configuration and THS | Enter in the combined flap/THS field using the displayed convention, such as 1/UP0.8, and set the physical flap lever and trim to agree. |
| Runway shift or intersection data | Confirm the correct runway in the flight plan and enter the returned take-off shift where the FMS provides that field. Do not use a full-runway result from an intersection. |
| Packs and engine anti-ice | Set the overhead systems to the calculated state. These are configuration instructions, not V-speed fields. |
After entry, compare all three FMS speeds with the calculator rather than accepting populated fields by sight. There is no safe fixed set of A380 speeds: weight, runway, wind, surface state and configuration can all change them, as explained in our guide to how A380 V1, VR and V2 are determined.
A380 THS: what to enter and how to set it
THS is the calculated trimmable horizontal stabiliser setting for the aircraft’s take-off CG and configuration. It is not a standard value for every A380, and a loading or flap change can produce a different setting.
Preserve the direction shown by the calculator. UP means trim in the nose-up direction and DN means nose-down; do not discard the letters or convert them to an assumed positive or negative sign. For example, a result of UP0.8 must not be entered as DN0.8 or simply 0.8 where the direction is required.
- Enter flap and THS in the FMS. On the PERF TAKE OFF page, enter the returned flap setting and THS in the combined field using the format shown by the FMS, such as
1/UP0.8. - Set the actual stabiliser. Use the A380X pitch-trim control on the centre pedestal, or a correctly assigned trim command, until the aircraft’s physical pitch-trim indication agrees with the calculated direction and value. Entering THS in the FMS records the expected setting; it is not a substitute for checking the stabiliser itself.
- Cross-check before departure. Compare the calculator result, the FMS flap/THS entry and the actual pitch-trim readout. Check the flight-control indication where required and run the take-off configuration check. A normal configuration message confirms that the aircraft is within an accepted range, but it does not excuse a mismatch with the calculated value.
A mistake we see constantly is entering the flap/THS pair in the FMS while leaving the physical trim at its previous position. Also check for an elevator-trim axis or controller binding that keeps moving the stabiliser after it has been set.
Should I use FLEX or TOGA in the A380X?
Use FLEX only when the official calculator returns a valid FLEX temperature for the exact runway, weight, weather and systems configuration.
Enter the returned temperature without increasing it to obtain lower thrust. A FLEX temperature cannot be below the outside air temperature, and the FMS may reject a value outside its permitted range. With a valid FLEX result, move the thrust levers to the FLX/MCT detent for take-off.
If the calculator explicitly requires full thrust, leave the FLEX field blank and use the TOGA detent. TOGA does not cure an overweight aircraft, insufficient runway distance or unsupported contaminated-runway calculation; the underlying performance result must still be valid.
Why does the A380X calculator show no result or reject FLEX?
A missing or rejected result usually indicates incorrect input units, unsupported runway data or a departure that cannot meet the required performance margins in the selected configuration.
| Problem | Checks and corrective action |
|---|---|
| No valid result | Recheck TOW, CG, runway end, intersection, available distance, wind direction, temperature, QNH units and runway state. If the inputs are correct, use the full runway, reduce weight, choose a runway with a better wind component or test another calculator-supported flap configuration. |
| Airport, runway or intersection missing | Do not calculate against a different runway and reuse the output. Use the calculator’s supported runway or custom-distance workflow if available; otherwise a valid result has not been produced. |
| FLEX field rejects the value | Confirm that OAT and FLEX were not swapped, that the returned value was copied without a sign or unit error, and that the result belongs to the selected configuration. If the calculator specifies TOGA, leave FLEX blank. |
| V-speeds are rejected or look wrong | Check that each speed went into the correct field and that V1 ≤ VR ≤ V2. Recalculate after correcting the inputs rather than forcing the FMS to accept invented values. |
| THS differs from the aircraft indication | Verify the final CG and flap configuration, then set the physical trim to the calculated value. Check for trim bindings that are moving it again. |
| Runway, weather or loading changed | Discard the old result and recalculate. Update the FMS only after the new runway, take-off weight, surface condition and configuration are settled. |
Packs and engine anti-ice are common hidden causes of a mismatch. If the calculation assumed packs off or anti-ice off but the aircraft reaches the runway with those systems in another state, either restore the calculated configuration or calculate again.
When must take-off performance be recalculated?
Recalculate whenever the original result no longer describes the aircraft or departure point that will actually be used.
- ATC assigns another runway or intersection.
- Fuel or payload changes, or taxi burn differs enough to change take-off weight materially.
- Wind, temperature, QNH or runway condition changes.
- The flap selection, pack state or engine anti-ice requirement changes.
- The FMS departure is rebuilt and the take-off entries are cleared or no longer match the runway.
Keep the old result out of the FMS while recalculating so that stale values are not mistaken for the accepted figures. The final check is always calculator output against FMS entries and the physical aircraft state.
Can I use the FBW calculator for an iniBuilds A380?
No. An iniBuilds A380 performance calculator, EFB procedure and aircraft output are specific to the iniBuilds implementation and are not interchangeable with FlyByWire A380X data.
iniBuilds users should use the performance application supplied with their installed aircraft where available, or follow the calculator and manual workflow specified for that product version. Its loading model, engine performance, EFB fields, FMS entry format and supported runway data may differ, so do not paste FBW V-speeds, FLEX temperatures or THS values into it unchanged.