You have the free A32NX installed, you are sitting in a cold and dark cockpit, and somewhere between the batteries and the PERF page it stopped making sense. Here is the whole sequence in one line: batteries on, external power, fire test, APU master and start, ADIRS to NAV, cockpit prep, MCDU, engine 2 then engine 1, T.O CONFIG test, taxi.
That order is not arbitrary, which is the part most of a FlyByWire A32NX startup guide leaves out. Two things in the sequence are clocks that run whether you are ready or not (the APU and the IRS alignment), and everything else is arranged around them. If you want the exhaustive switch-by-switch version to follow along with in the cockpit, the full interactive A32NX checklist covers all 17 phases and 165 steps from planning to shutdown. This post is the first 81 of those steps with the reasoning attached, plus every gotcha that reliably stops people.
One note before anything else, because it saves confusion later: if you came over from the 737 you are looking for the FMC. On an Airbus there isn't one. The box on the pedestal is the MCDU (Multipurpose Control and Display Unit), and it is the crew's interface to the FMGC (Flight Management Guidance Computer), the thing that actually does the computing. The wider system that builds your climb and descent profiles is the FMGS. Same job as a Boeing FMC, different name, and the A32NX community will notice which one you use. If Boeing is where you came from, our PMDG 737 cold and dark start guide is the mirror image of this page.
The short version
- BAT 1 and BAT 2 on. Listen for the chimes.
- External power on when the green AVAIL light shows.
- APU fire test. Press and hold until the warning and the aural alert trigger.
- APU MASTER SW on, then APU START. Roughly a minute to 100%.
- APU BLEED on, APU GEN on/auto. Then wait about another minute before you think about engines.
- ADIRS: all three IR knobs to NAV. Do this now, not later. It is the long pole.
- Cockpit prep while the IRS aligns: fuel pumps, hydraulics, oxygen, baro, ATIS.
- MCDU: INIT A, F-PLN, RAD NAV, INIT B, PERF TAKEOFF.
- Beacon on, start clearance, engine 2 master on, then engine 1.
- APU off, spoilers armed, flaps set, T.O CONFIG test, taxi.
The rest of this page is why each of those exists and what breaks when you get it wrong.
Before you start: which A32NX you are flying
Stable vs Development
FlyByWire ships two editions through the FlyByWire Installer. Stable lags development, gets compatibility patches when the sim updates, and moves in controlled upgrades every few months. Development rebuilds on every commit to master, so it has the newest features and the newest bugs.
Everything on this page is anchored to Stable. That matters more than it sounds: a specific LSK or page layout can be correct on one edition and wrong on the other, which is exactly why half the tutorials you find contradict each other. Install through the Installer and take Stable. Manual GitHub installs are discouraged by FBW themselves and are how people end up on a build nobody can support.
A note on MSFS 2024
The A32NX runs in MSFS 2024 through compatibility rather than as a native 2024 aircraft. This is the part of the aircraft's situation most likely to change, so check the FlyByWire docs for the current state rather than trusting any guide, this one included. The procedure below is unaffected either way.
Power-up: batteries to APU
BAT 1 and BAT 2, external power
Both battery switches on. You should hear chimes, and the voltage should read above 25.5 V. Then External Power on when the green AVAIL shows, which spares your batteries the whole preflight.
Do not rush from batteries straight into the fire test. The Flight Warning System needs roughly 40 to 50 seconds to self-test after you power up, and testing before it has finished tells you nothing useful.
The fire test everyone skips
Press and hold the APU FIRE TEST until the warning and the aural alert both trigger. Ignore any tutorial quoting you a hold time in seconds. Note instead where the test sits in the sequence: before the APU start, not after. On the real aircraft, holding that button down for more than about three seconds with the APU already running is how you trigger an automatic APU shutdown and discharge the fire bottle, which is why the test belongs in the dead-APU window rather than whenever you get round to it.
People skip it because nothing bad happens in the sim if you do, which is precisely why it is worth doing: it is one of the few places the A32NX rewards flying it as a procedure rather than a puzzle.
APU MASTER SW and START (the two one-minute waits)
APU MASTER SW on, then press APU START. It takes up to a minute to reach 100% N, and the START button light going out is your cue.
Then APU BLEED on and APU GEN on/auto. Here is the wait people miss: after APU BLEED comes on, give it roughly another minute before engine start. The bleed air needs to actually be there and stable. Starting into a bleed system that has not settled is a classic cause of a start that hangs and leaves you wondering what you did wrong.
Cockpit preparation
ADIRS to NAV: do this first, not last
Three IR knobs to NAV. Do it as soon as you have power, then do everything else while it runs.
There is no one alignment time, which is exactly why every guide quotes you a different one. Real IRS align time scales with latitude, and the A32NX models that: FlyByWire's own rework of the timing puts it at roughly 5 minutes near the equator, 6 to 8 across the continental US, and 11 to 12 up around Anchorage. FlyByWire describe their realistic setting as about 8 minutes.
So do not estimate it at all. The ECAM shows an IRS IN ALIGN memo counting the remaining minutes down, and that number is the only one that applies to where you are actually parked. Two rules while it runs:
- It must finish before engine start or pushback.
- Do not move the aircraft during alignment. Movement restarts the process. If you slew, get pushed, or reposition mid-align, you have just bought yourself another full alignment.
If you would rather not wait, the flyPad EFB has an ADIRS align time setting under Realism: realistic, a faster option of about 2 minutes, or instant. No judgement either way. But the reason ADIRS-first is worth making a habit is that a full alignment running behind your MCDU setup costs you nothing, while the same alignment discovered after you have called for pushback costs you all of it.
Fuel pumps, hydraulics, oxygen, baro
While the IRS spins:
- Fuel Pumps (all 6) on: the centre tank pumps plus the four wing tank pumps.
- Hydraulic panel: green, blue and yellow all on, no faults. Electric pumps and PTU as required.
- Crew Oxygen on. Push the CREW SUPPLY guard so the white OFF light goes out.
- Speed Brake Lever retracted and disarmed, Engine Masters 1 and 2 off, ENG Mode Selector to NORM, gear down, thrust levers idle.
- Baro reference (QNH) set on both PFDs and the ISIS, from the ATIS.
- ECAM STATUS reviewed for maintenance or fault messages.
Transponder while you are here: set XPDR to STDBY, then double press CLR to clear the field before keying your code. The double press catches people constantly.
MCDU setup (the part people actually get stuck on)
D.I.F.S.R.I.P.: the order the pages want
FlyByWire teaches the page flow as a mnemonic, and it is worth memorising because the pages genuinely depend on each other:
DATA, INIT A, FLIGHT PLAN, SECONDARY FLIGHT PLAN, RAD NAV, INIT FUEL PRED, PERF.
Our checklist runs the same order across steps 27 to 42. Work out of sequence and you will find pages that refuse entries because the FMGC does not have what it needs yet.
INIT A: city pair, cost index, CRZ FL
Company route or ICAO FROM/TO, alternate, flight number, cost index, cruise FL and temperature.
On cost index: use the value from your OFP. Ignore anyone quoting you a "normal" number. FlyByWire's own beginner walkthrough uses CI 10, our checklist note suggests 20 to 60 for short-haul, and real airlines vary it by fuel price and schedule pressure. The OFP is the answer, and there is no general one.
Importing from SimBrief with INIT REQUEST (and what it will not import)
Set your SimBrief ID once in the flyPad EFB (in Settings, under the third-party options, either by linking your Navigraph account or entering your SimBrief user ID directly). Then, in the MCDU:
MCDU MENU -> ATSU -> AOC MENU -> INIT/PRESS -> INIT DATA REQ, then INIT REQUEST at LSK2R on INIT A.
Two things to know, and the second one is the biggest gotcha on this page:
What it imports: departure, arrival, and the route. The route requires "Detailed Navlog" enabled in SimBrief, or you get the city pair and an empty middle. Tick it when you dispatch and hit Save Default, so a future OFP cannot quietly drop it on you. It does not import your runway, SID, STAR or approach. Those stay manual because they depend on what ATC actually gives you, which is also why the real aircraft does not import them.
What kills it entirely: picking your airports in the MSFS world menu before you load in. Setting the arrival alone is enough. The aircraft imports the world-map plan instead, FROM/TO comes up already filled, and INIT REQUEST is simply not on the page. FlyByWire calls this out on two separate documentation pages independently, which tells you how often it happens. Load to a parking spot, not a flight.
If you want to eyeball the figures the MCDU is about to ask for before you are in the seat, our SimBrief OFP preview tool parses the OFP XML and surfaces the block fuel, ZFW and V-speeds in one place.
F-PLN: SID, airways, STAR, and killing discontinuities
Pick the assigned runway and SID, verify the airways and waypoints against the OFP, then set the expected STAR and approach. Then clear the discontinuities.
This is where most flight plans go wrong quietly. A discontinuity left in the plan is the FMGC telling you it does not know how to get from one leg to the next, and it will happily let you take off with it there. Then it stops flying the route in the cruise and you get to troubleshoot at Mach 0.78. Walk the whole F-PLN top to bottom before you leave the gate.
RAD NAV: verify the auto-tuned NAVAIDs, or set the ILS for the planned approach.
INIT B / FUEL PRED: ZFW, ZFWCG, block fuel
Two entries, both easy to get wrong.
ZFW and ZFWCG: press LSK1R to pull the calculated values into the scratchpad, then LSK1R again to enter them. Boarding needs to be complete or in progress for those numbers to be accurate. Our checklist carries a warning on this step for a reason: enter them from the loadsheet exactly, because errors here corrupt your takeoff trim and every prediction the FMGC makes for the rest of the flight. If you are flying without a loadsheet and need to work out sensible numbers yourself, the weight and balance calculator will get you a defensible ZFW and CG.
Block fuel at LSK2R, in TONNES, rounded to one decimal. 4.7 means 4,700 kg. This is the single most common MCDU entry error in the aircraft. Type 4700 and you have just told the FMGC you are carrying 4,700 tonnes of fuel.
And the one that catches everyone at least once: MCDU fuel planning is only a reference point. It does not load fuel into the aircraft. Entering block fuel tells the FMGC what to expect, not the fuel truck what to pump. Fuel goes in through the EFB.
PERF TAKEOFF: V-speeds, FLEX, THS, CONF
V1, VR, V2 can come straight from the FMGC: LSK1L puts the computed V1 in the scratchpad, LSK1L again enters it. Repeat for VR and V2.
FLEX TO TEMP for a reduced-thrust takeoff, usable at sea level from 45 C to 74 C, or the current OAT if that is higher than 45. Below that window the entry does nothing for you. Otherwise plan TOGA.
THS takes the format /X.XDN or /X.XUP (so /0.4DN), from the loadsheet, subject to airline SOP.
Flaps CONF, usually 1 or 2 depending on runway and weight, then verify THR RED / ACC ALT make sense for the terrain you are climbing out over.
Engine start
Why engine 2 goes first
Every guide tells you to start engine 2 first. Almost none tell you why, so: the parking brake runs on the yellow hydraulic system, and the yellow system's engine-driven pump is on engine 2.
Before start, your parking brake is living on the yellow accumulator, and accumulator pressure drops with every brake application. Start engine 2 first and you get the yellow EDP online at the earliest possible moment, so you are not leaning on a finite reservoir in the window between pushback and having engines. It is Airbus-recommended rather than a law of physics: airlines do vary it, and so should you if a given situation makes the other side the sensible one to spin up first.
What a normal start looks like
ENG Mode Selector to IGN/START, then ENG 2 Master on. The start is automatic. Watch N2 come up, then fuel flow, then EGT. Confirm it stabilises at idle, then ENG 1 Master on and repeat.
Once both are stable: ENG Mode Selector back to NORM, and check both engines at idle with no ECAM cautions.
Our checklist carries specific EGT and idle N1 figures on these steps; treat them as our working values rather than gospel. What you are actually watching for is the shape of it: a start that hangs, or an EGT climbing when it should be settling.
After start to taxi
APU BLEED off, then APU MASTER SW off (engine generators have the electrics now, and the APU burns fuel for nothing). Ground spoilers armed by pulling the speed brake lever up. Flaps set per the PERF page. Pitch trim (THS) set, confirmed in the green band for your takeoff CG.
The T.O CONFIG test
Two checks, in this order:
- ECAM TO Memo: NO BLUE. Blue items are things you have not done yet.
- T.O CONFIG TEST: press. The ECAM must show CONFIG NORMAL before you taxi.
The memo tells you what is outstanding. The test tells you the aircraft agrees. Doing the test at the gate rather than at the hold short means you find your unarmed spoilers with the parking brake set, not with a queue behind you.
Then: taxi clearance, nose/taxi light on, brake check early in the taxi, instruments and heading checked, autobrake MAX for takeoff abort protection.
The gotchas that catch everyone
- Picking your airports in the MSFS world menu breaks the SimBrief integration. The arrival alone does it, and INIT REQUEST never appears. Load to a parking spot.
- No "Detailed Navlog" in SimBrief means no route imports. You get the city pair and nothing between.
- Block fuel is in tonnes to one decimal. 4.7, not 4700.
- MCDU fuel entry does not load fuel. That is the EFB's job.
- Moving during IRS alignment restarts it. All of it, whatever the ECAM was counting down.
- The IRS must be aligned before pushback, so start it before everything else.
- INIT REQUEST does not bring your runway, SID, STAR or approach. Those are always manual.
- Discontinuities left in the F-PLN will let you depart and then quietly stop flying your route.
- The transponder needs a double CLR press to clear the field before you key the code.
- Wait roughly a minute after APU BLEED before engine start, and give the FWS 40 to 50 seconds after batteries before the fire test.
- ZFWCG errors corrupt your takeoff trim, and the aircraft will not save you from a plausible-looking wrong number.
Fly it with the checklist
Reading a startup is not the same as flying one. The interactive A32NX checklist has all 165 steps with the exact switch names and expected values, tracks your progress by phase, and works on a phone next to your keyboard. The first seven phases are everything on this page, from Pre-Flight Planning through After Start / Taxi. The other ten get you to the gate at the far end.
Take Stable, load cold and dark at a parking spot, and put the ADIRS to NAV before you do anything else.