Learn how to prepare an airliner from cold and dark to takeoff, covering power, FMS setup, engine start, taxi checks and configuration.
To prepare a cold-and-dark airliner for takeoff in a flight simulator, establish electrical power, align its navigation systems, load and verify the route, configure the aircraft, arrange pushback, start and stabilise the engines, then complete the after-start, taxi and before-takeoff checks. The exact switch order must follow that aircraft’s checklist.
This general workflow applies across Microsoft Flight Simulator, X-Plane, Prepar3D and similar simulators. High-fidelity add-ons reproduce far more of it than simplified default aircraft, so do not copy switch positions, engine-start parameters or bleed-air procedures from a different type.
Which power source should you use at the gate?
Use ground power when it is available; otherwise start the auxiliary power unit according to the aircraft procedure. The battery normally powers the initial checks and control circuits, but it is not intended to carry an airliner’s full electrical load throughout preparation.
| Power source | Choose it when | Check before continuing |
|---|---|---|
| Ground power unit | The stand provides external power and the aircraft shows it as available | External power is selected and the main electrical buses are powered |
| APU | No ground power is available, or APU electrical power and start air will be needed | The APU has stabilised and its generator or bleed supply is online |
| Battery only | Performing the first cockpit checks or starting the APU | Battery voltage is adequate and unnecessary loads remain off |
A mistake we see constantly is disconnecting ground power before the APU generator is carrying the buses. That produces a dark cockpit again and may erase unfinished FMS work in less forgiving aircraft.
Cold-and-dark to takeoff procedure
- Confirm the starting state. Load the aircraft at a parking stand rather than on the runway. Set hardware throttles to idle, check the landing gear is down, and confirm the parking brake or wheel chocks are holding the aircraft. Some simulators override a cold-and-dark preset when a runway start is selected.
- Use the correct cockpit flow and checklist. Select documentation for the exact aircraft and add-on, not merely the same manufacturer. A flow positions the controls; the checklist verifies the critical items afterwards. Our guide to using an aircraft-specific simulator checklist explains that distinction and the normal order of checks.
- Establish electrical power. Switch on the battery or standby system as prescribed, then connect ground power or start the APU. Verify the displays, electrical buses and essential instruments are powered instead of assuming that an illuminated switch means the source is online.
- Begin navigation-system alignment. Set the IRS, IRU or ADIRS selectors as required and initialise the aircraft position. Detailed aircraft may take several minutes to align, and moving the aircraft can interrupt the process. Simplified models may align instantly or omit this stage.
- Programme and verify the FMS. Enter or import the route, then check the departure runway, SID, cruise altitude, arrival assumptions, aircraft weight and fuel. Complete the performance pages required by the model, enter the takeoff speeds and inspect the route display for discontinuities, duplicate waypoints or an incorrect first leg.
- Prepare the remaining systems. Configure pressurisation, air conditioning, fuel, hydraulics, emergency lighting, signs, radios and anti-ice according to the checklist and weather. Set the initial cleared altitude and relevant guidance-panel selections. There is no universal overhead-panel pattern that is safe for every airliner.
- Brief the departure and prepare for pushback. Confirm the runway, initial route, first cleared altitude, expected takeoff mode and rejected-takeoff plan. Close the doors, remove incompatible ground equipment, obtain clearance where simulated, and switch on the beacon at the point specified by the aircraft procedure.
- Start and monitor the engines. Establish the required pneumatic or electrical start source, configure the packs and bleed system as directed, operate the starter, and introduce fuel only at the prescribed stage. Watch rotation, fuel flow, exhaust temperature and oil pressure throughout. The underlying sequence and common faults are covered in our aircraft engine-start guide.
- Complete the after-start flow. Confirm the engine generators, bleed system, packs, hydraulic pumps and probes are correctly configured. Shut down the APU only after replacement electrical and pneumatic sources are stable. Set takeoff flaps, trim and speedbrake, then perform the flight-control check.
- Taxi and run the final checks. Release the parking brake or chocks, check the brakes as the aircraft begins moving, and taxi at a controllable speed. At the holding point, verify the cabin, transponder, exterior lights, takeoff configuration and runway before entering it. Our taxi and takeoff sequence covers the handling from this point.
Do you need to programme the FMS before engine start?
Programme and verify the FMS at the gate whenever the aircraft supports it. Although an engine can usually be started without a completed route, entering data while parked leaves time to catch route errors and calculate the required takeoff settings without rushing during taxi.
A route imported from the simulator’s flight planner may populate only the lateral waypoints. It does not guarantee that the runway, departure procedure, performance data, V-speeds or autopilot altitude are correct. Check each of those in the cockpit.
Why will the airliner not start or move?
Most cold-and-dark failures come from a missing power, start-air or fuel condition rather than a failed simulator. Work backwards from the symptom instead of repeatedly cycling the starter.
| Symptom | Likely cause | What to check |
|---|---|---|
| Cockpit remains dark | No usable electrical source | Battery state, external-power selection, APU generator and bus indications |
| Navigation system stays in ALIGN | Position not initialised, selector incorrect or aircraft moved | FMS position entry, alignment selectors and parking status |
| Engine does not rotate | Required start energy is unavailable | APU bleed or electrical supply, isolation valves, packs and starter selector |
| Engine rotates but does not light | Fuel or ignition is missing | Fuel quantity, pumps, fuel control lever and ignition/start mode |
| Aircraft will not roll | A restraint or control input remains active | Parking brake, chocks, pushback tug, toe brakes and duplicated controller bindings |
| Takeoff-configuration warning sounds | A required control is outside its takeoff range | Flaps or slats, stabiliser trim, speedbrake, parking brake and aircraft-specific items |
How do you know the airliner is ready for takeoff?
The aircraft is ready only when the checklist is complete, its configuration warning system reports no fault, and the crew setup matches the actual runway and clearance. Before crossing the holding point, verify:
- The correct runway and departure path are selected and displayed.
- Takeoff speeds are entered and correspond to the chosen flap setting.
- Flaps or slats, stabiliser trim and speedbrake are in their required takeoff positions.
- The flight controls have been checked and move in the correct direction.
- The initial altitude, heading or route mode and flight directors are set as required.
- Engines and systems show no unresolved warning, caution or abnormal indication.
- The cabin, transponder, exterior lights and weather-dependent systems are configured.
- The runway is identified visually and on the navigation display before takeoff power is applied.
Do not silence or ignore a takeoff-configuration warning simply because the aircraft still accelerates. It is usually identifying a flap, trim, spoiler or brake setting that can make the simulated departure unstable or prevent normal rotation.