Diversion to Alternate
PremiumintermediateMid-planning, ATC sends you to Brussels instead of Paris. Rebuild the flight around a new destination without unpicking the whole thing.
What this scenario covers
A diversion on the MCDU is a destination change plus everything that follows from it: the arrival end of the flight plan is now wrong, the fuel prediction is against the old airport, and the alternate may no longer make sense. This scenario walks the INIT-side of that change and the re-verification that must follow.
The temptation is to change the destination and stop. The discipline is to treat the change as invalidating the second half of the flight plan until you have looked at it.
How it applies in flight ops
Diversions happen for weather, for a closed runway, for a medical, and the decision is usually made under time pressure with the cabin asking questions. The box work is the easy part; what makes it safe is that it is a known sequence rather than an improvisation.
Fuel is the constraint that decides the diversion, and it is checked before the box is touched — a destination the aircraft cannot reach with reserves is not a destination. The FMGS prediction after the change is a cross-check on that decision, not the basis for it.
Fly this one with Premium
Everything about this scenario is on this page, steps included — reading it costs nothing and always will. What Premium adds is doing it: the MCDU validates every entry as you make it, tells you when an entry was accepted but wrong, and saves your progress across devices.
Step-by-step: Diversion to Alternate
- You're planning a flight to Paris. Enter EGLL/LFPG and press 1R.
- Enter flight number BAW304. Type BAW304 and press 3L.
- Set cost index to 35. Type 35 and press 5L.
- ATC UPDATE: "BAW304, divert to Brussels EBBR due to weather at destination." Change your route to EGLL/EBBR. Type EGLL/EBBR and press 1R.
- Update flight number to BAW9999 (diversion callsign). Type BAW9999 and press 3L.
- Update cost index to 40 for the diversion. Type 40 and press 5L.
- Set cruise level to FL310 — shorter flight, lower altitude. Type FL310 and press 6L.
- Go to F-PLN to verify your new route shows EGLL and EBBR (not LFPG).
What to take away
- Changing the destination invalidates the arrival half of the flight plan.
- Re-check fuel prediction and alternate after the change, not before.
- Diversion decisions are fuel decisions first and programming second.
- A known sequence beats improvisation when the workload is high.
The rest of Enroute Operations
Step Climb Mid-Cruise
PremiumadvancedMid-Atlantic at FL340, hours of fuel burnt off, and the aircraft can now fly higher and cheaper. Check the maximum, then step up.
📍 EGLL → KJFK⏱ ~5 min📊 6 stepsATC Shortcut: Going Direct
Premiumintermediate"Direct OCK" — five seconds of radio and a chunk of your flight plan gone. Stage it, recover from a mis-hear, and execute.
📍 EGLL approach — direct routing⏱ ~4 min📊 5 stepsSpeed & Altitude Constraints (VERT REV)
PremiumintermediateATC wants you at an altitude by a waypoint. The vertical revision page is where that promise gets written into the flight plan.
📍 EGLL → DVR → LFPG⏱ ~4 min📊 5 stepsEntering a Holding Pattern (HOLD)
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📍 HOLD AT LFPG⏱ ~4 min📊 6 steps
Background reading
- GuideFenix A320 Failure Training: Master the 4 Emergencies Every Sim Pilot Should Practice
Practice engine failure, engine fire, rapid decompression and unreliable airspeed in the Fenix A320 — step-by-step ECAM drills and how to stay calm.
- GuideThe A320 MCDU Explained: Every Page, Simply
What is the A320 MCDU? A plain-English guide to every Airbus MCDU page — INIT, F-PLN, PERF, RAD NAV and more. Practice free in our MCDU trainer.
- GuideHow to File an IFR Flight Plan in MSFS 2024 and Get ATC to Work Properly
File an IFR flight plan in MSFS 2024 from the World Map or EFB — cruise altitude rules, terrain traps, ATC quirks, and why it disagrees with SimBrief.