Program the Airbus A320 MCDU/FMS in MSFS: enter INIT, route, SID/STAR and PERF data, then fix discontinuities and managed-mode problems.
To program the Airbus A320 MCDU/FMS in Microsoft Flight Simulator, power and align the aircraft, complete INIT, build the F-PLN, select the runway, SID, STAR and approach, enter PERF data, then inspect every leg. Remove only unwanted discontinuities and confirm the Flight Mode Annunciator shows the guidance you intend.
What are the Airbus A320 FMS and MCDU?
The MCDU is the keypad and display used to communicate with the A320’s Flight Management and Guidance System, commonly shortened by simmers to FMS or FMGS.
The FMGS holds the route, calculates predictions and supplies guidance targets. The MCDU is its interface; it does not directly control the aeroplane. The FCU determines whether the aircraft follows managed FMS commands or selected headings, speeds and altitudes, while the Flight Mode Annunciator on the PFD shows what it will actually do.
Our guide to how the MCDU, FCU, PFD and navigation display work together explains those cockpit relationships in more detail.
Which A320 FMS pages do you need?
The essential programming pages are INIT, F-PLN, departure and arrival revisions, INIT B or fuel prediction, and PERF.
| Page or function | What you enter | Frequent mistake |
|---|---|---|
| INIT A | Origin, destination, alternate if required, flight number, cost index and cruise level | Building the route before confirming the airport pair |
| F-PLN | Waypoints, airways, direct legs, runway, SID, STAR, transitions and approach | Keeping duplicated imported legs or selecting the wrong waypoint with a repeated identifier |
| INIT B or fuel page | Zero-fuel weight, centre of gravity and block fuel where modelled | Using figures that do not match the aircraft loading |
| PERF TO | Flap and trim setting, V-speeds, FLEX temperature if used, and acceleration data | Guessing take-off speeds or assuming every add-on calculates them automatically |
| PERF APPR | Pressure, temperature, wind, minima, landing configuration and approach-speed review | Leaving old weather or minima after changing the runway |
| RAD NAV | Manual VOR or ILS tuning when required | Overriding valid automatic tuning without a reason |
How to program the Airbus A320 MCDU/FMS step by step
The reliable sequence is to establish power and position, choose one route source, initialise the FMGS, construct the flight plan, enter performance data and verify the result in PLAN mode.
Power the aircraft and start ADIRS alignment. Use external power or the APU as appropriate, then set the ADIRS selectors to NAV. Detailed add-ons may ask you to confirm the airport or GPS position on an IRS INIT page; simpler A320 implementations automate this. You can enter the route while alignment continues, but normal navigation guidance depends on completed alignment.
Choose one primary route source. A Microsoft Flight Simulator World Map plan may already be present in the MCDU, especially in a standard aircraft. Detailed add-ons may instead use their own tablet, company-route or manual-entry system. Do not import a complete plan and then enter the same route again by hand.
Complete INIT A. Enter the origin and destination as an airport pair, followed by the flight number, alternate, cost index and planned cruise flight level where supported. Cost index affects speed and economy predictions; it cannot correct a broken route.
Build or inspect the en-route F-PLN. Add fixes in sequence, or use airway entry from the appropriate waypoint’s lateral-revision page if the aircraft supports it. When several waypoints share an identifier, compare their coordinates or region with the intended route. A wrong duplicate fix can place the next leg hundreds of miles away.
Select the departure. Open the origin airport’s departure page, choose the runway, then the SID and transition that connect to the first en-route fix. A runway-only departure is valid when no SID is planned and vectors or a direct clearance will be used.
Select the arrival and approach. Open the destination arrival page and choose the expected approach, STAR, transition and approach via as applicable. Detailed FMGS implementations create a temporary flight plan; inspect it before pressing
INSERT, or useERASEto reject it.Resolve discontinuities selectively. Delete a discontinuity only when the leg before it should connect directly to the leg after it. Breaks associated with radar vectors or parts of a missed approach may be intentional. If no controller will provide the expected vector, plan a valid direct or intercept before reaching the break.
Enter weights and fuel. On INIT B, fuel prediction or the equivalent page, enter or import zero-fuel weight, zero-fuel centre of gravity and block fuel. Complete this before engine start on add-ons that reproduce the Airbus flight-phase limitation on INIT B.
Complete PERF TO. Enter the take-off flap and trim configuration, V1, VR and V2, FLEX temperature when using a reduced-thrust take-off, and thrust-reduction or acceleration data requested by the aircraft. Use the implementation’s supported performance calculation rather than inventing plausible-looking speeds.
Verify the complete plan. Put the navigation display in PLAN mode and scroll through F-PLN one waypoint at a time. Check the first leg after take-off, airway joins, altitude and speed constraints, the STAR-to-approach connection, final approach and missed-approach routing. Loops, sharp reversals and long off-route lines usually reveal a bad transition, duplicated leg or wrong waypoint.
Complete PERF APPR before descent. Enter the destination pressure, temperature and magnetic wind, then the appropriate barometric or radio minimum in the matching field. Select the planned landing configuration where available and review the calculated VAPP. Repeat this check after any runway or approach change.
How do I enter a SID, STAR and approach in the A320?
Attach the SID to the origin and the STAR and approach to the destination, selecting procedures that connect logically with the en-route flight plan and match the expected clearance.
For departure, the safe order is runway, SID, transition. For arrival, Airbus units commonly ask for the approach, STAR, transition and approach via, although the displayed selection order varies between MSFS aircraft. A transition joins the en-route plan to the STAR; an approach via joins the arrival to the final approach.
If the landing runway is uncertain, either leave the arrival open until it is known or load the most likely option for descent planning and expect to revise it. After a late runway change, reselect the complete arrival through the destination page and inspect every leg from the last en-route fix to the runway. Editing isolated fixes often leaves part of the old procedure behind.
A missing procedure is not always an aircraft fault. The World Map planner and an add-on may use different navigation databases or cycles, so one can contain a SID, STAR or transition that the other does not. Use a procedure available in the aircraft’s database or synchronise its navigation data where that product supports it.
Should I delete every F-PLN discontinuity?
No: a flight-plan discontinuity can represent either a routing error or an intentional gap where ATC is expected to provide vectors.
Before deleting one, read the waypoint above and below it and inspect the resulting track on the navigation display. Deleting the break tells the FMGS to connect those legs directly, which may create an unsafe-looking turn or cut across the intended procedure.
Delete it when two valid consecutive route legs should connect and the displayed track confirms the join.
Keep it temporarily after a vectors instruction or where the procedure deliberately ends without a defined next leg.
Use DIR TO when ATC clears the aircraft directly to a later fix or when recovering from a route that has stopped sequencing.
On a conventional Airbus MCDU, deletion is normally performed with CLR followed by the line-select key beside the discontinuity. Do not repeatedly press CLR against every unfamiliar entry: runway points, pseudo-waypoints such as the top of descent, and procedure legs are not clutter.
Why is the A320 not following the FMS route?
The A320 usually ignores the programmed route because the active flight plan is broken, the aircraft is in selected heading, or NAV guidance has not been armed or captured.
| Symptom | Likely cause | What to check |
|---|---|---|
| The aircraft follows a heading instead of the magenta line | Selected HDG mode is active | Intercept the route at a sensible angle, command managed NAV and confirm the FMA changes to NAV |
| The route stops at a discontinuity | No continuous lateral leg exists | Follow the expected vector, use DIR TO, or delete the break only after checking the new track |
| The magenta line loops or leaves the region | Wrong duplicate waypoint, duplicated procedure or bad transition | Inspect in PLAN mode and reinsert the affected segment |
| The aircraft will not climb or descend as expected | FCU target, selected mode or an FMS constraint is limiting it | Check the selected altitude, active constraint and FMA together |
| A SID, STAR or approach is absent | Navigation-database mismatch | Choose a procedure present in the aircraft or align the data sources where supported |
| No localiser or glideslope appears | Wrong approach, missing tuning or approach mode not armed | Confirm an ILS is inserted and correctly tuned, then arm the appropriate mode at a suitable intercept; an RNAV approach does not provide ILS signals |
The FMA is the final authority. Pushing an Airbus FCU knob normally requests a managed mode, while pulling it requests a selected mode, but capture conditions and the active flight phase still matter. Our explanation of managed and selected modes on the A320 FCU covers the push-pull logic and common mode traps.
Scratchpad messages also identify many entry problems. FORMAT ERROR means the entry syntax is wrong, NOT ALLOWED means that action or field is unavailable in the present context, and NOT IN DATABASE means the typed identifier is absent from the aircraft’s navigation data. Clear the message, correct the entry and retry; do not erase the whole flight plan.
Should I use the World Map planner or program only the MCDU?
Use the World Map import for speed and an MCDU-first workflow for control, but treat the flight plan displayed in the aircraft as the final authority.
Choose World Map import for a quick IFR setup in a standard MSFS A320, then verify all procedures, transitions and constraints in the MCDU.
Choose MCDU-first programming when practising Airbus procedures, using a detailed add-on or expecting route and runway changes.
Use a mixed workflow cautiously. A mistake we see repeatedly is importing a SID and approach, then adding both again through the MCDU. The resulting duplicate fixes may look acceptable until the aeroplane turns back towards an earlier leg.
What changes between the standard A320 and detailed add-ons?
The programming order stays broadly the same, but detailed Airbus add-ons expose more FMGS functions and require more complete data.
Standard MSFS implementations may integrate closely with the World Map, automate alignment or loading, and fill some performance fields.
Higher-fidelity A320s may use an independent route import, navigation database and electronic flight bag. They are also less forgiving of missing weights, fuel, V-speeds or approach data.
Page labels and available functions vary. INIT B, fuel prediction, airway entry, automatic radio tuning and temporary-flight-plan behaviour are not modelled identically in every aircraft.
For simmers who want a more complete Airbus flight-management implementation, our library carries the FlyByWire A32NX package for Microsoft Flight Simulator. Regardless of aircraft version, programming is not finished when the final field is filled; it is finished when the route, constraints, performance data and active guidance modes have been checked.
Once the MCDU is correct, our gate-to-gate A320 flying workflow shows how the programmed plan connects to take-off, managed climb, cruise, descent and approach.