INIT Page Basics

beginner
📍 Route: KJFK → EGLL⏱ ~2 minutes📊 6 steps🎓 Foundations

The INIT page is the first thing you touch on every flight. Six entries, two minutes, and the flight management computer knows what trip it is flying.

What this scenario covers

INIT A is where the flight gets its identity: the city pair in FROM/TO, an alternate, the flight number, a cost index and a cruise level. Enter the city pair and the FMGS pulls the airports out of the navigation database and starts a flight plan; everything else on the aircraft — the route, the performance predictions, the fuel figures — hangs off that first entry.

The one field that behaves differently is CO RTE, the company route. It takes a stored route identifier rather than a formatted city pair, and it is the one INIT field with no format check, so a plausible-looking entry is simply accepted. That is worth knowing before you type: the trainer now tells you when an entry was taken but was not what the step wanted.

How it applies in flight ops

On the line this happens at the gate, before the loadsheet arrives, usually from the OFP the crew were handed at briefing. It is deliberately the first job because nothing else can be entered until the FMGS knows the city pair — the route page will not accept waypoints for a flight that does not exist yet.

The cruise level entered here is not a commitment; it is the planning figure from the flight plan, and it gets revised in the air as weight comes off. What it does do is set the vertical profile the FMGS predicts against, which is why a wrong FL here quietly poisons every fuel and time prediction downstream.

Start this scenario

Open the SimTuts A320 MCDU trainer and select “INIT Page Basics” from the scenarios list to walk through it step-by-step on the simulated keypad.

Open trainer →

Step-by-step: INIT Page Basics

  1. The INIT page is where every flight starts. Enter a route by typing KJFK/EGLL into the scratchpad, then pressing 1R.

    The FROM/TO field tells the FMS which airports to route between. You get these 4-letter ICAO codes from your Operational Flight Plan (OFP) — the paperwork dispatch provides before every flight. KJFK = New York JFK, EGLL = London Heathrow. Getting this wrong means the FMS calculates the wrong route, fuel, and winds.

  2. Enter your alternate airport. Type EGKK and press 2L. The alternate is where you'd divert if you can't land at Heathrow.

    Every flight plan requires an alternate airport — a nearby field you can reach if the destination closes (weather, runway blocked, emergency). EGKK (Gatwick) is a common alternate for Heathrow: it's close enough that fuel reserves cover it, but far enough that different weather patterns apply. The dispatcher selects it on the OFP based on weather forecasts, runway availability, and fuel calculations.

  3. Enter a company route. Type KJFKEGLL1 and press 1L. Company routes are pre-stored flight plans that save time.

    Company routes are pre-built flight plans stored in the airline's FMS database. Instead of entering every waypoint manually, you type a route code from the OFP. The dispatcher has already verified this route for airspace restrictions and NOTAMs. If no company route exists, you'd build the route manually on the F-PLN page.

  4. Enter flight number BAW178. Type BAW178 and press 3L.

    The flight number comes from the OFP and matches your ATC callsign. BAW = British Airways ICAO code, 178 = flight number. It's how controllers identify you on radar and how ACARS and flight tracking systems associate this FMS with the correct flight.

  5. Enter cost index 52. Type 52 and press 5L.

    Cost index is set by the airline, not the pilots — you find it on the OFP. It represents the ratio of time cost to fuel cost. A higher number means "time is expensive, fly faster." The FMS uses it to calculate optimal climb, cruise, and descent speeds. Typical values: 0–20 for fuel conservation, 30–60 for normal ops, 80+ for tight schedules.

  6. Set cruise level to FL390. Type 390 and press 6L.

    Cruise flight level comes from the OFP and is coordinated with ATC. It depends on direction of flight (semi-circular rule: eastbound = odd levels like FL350/FL370/FL390, westbound = even), aircraft weight, and wind. FL390 is near the A320's ceiling and efficient for long-haul with low fuel load.

What to take away

  • FROM/TO is the entry that creates the flight — nothing works before it.
  • CO RTE takes a company route identifier, not a slash-separated city pair.
  • Cost index and cruise level come off the OFP and drive every prediction.
  • Two minutes of INIT saves the whole rest of the setup from being wrong.

The rest of Foundations

Background reading

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