Learn how to start a Boeing 747 cold and dark in a flight simulator, from electrical power and APU start to engine light-off and fault fixes.
To start a Boeing 747 cold and dark in a flight simulator, establish battery or external power, align the inertial reference system, start the APU, configure fuel and bleed air, then crank each engine and introduce fuel at the correct N2 indication. Finish by connecting generators and restoring hydraulics and air conditioning.
This is a general flight-simulator procedure. The Boeing 747-400 and 747-8 share the same broad flow, but switch positions, automation and simulated failures vary between MSFS, FSX, Prepar3D, X-Plane and individual add-ons. Use the checklist supplied with your aircraft whenever it conflicts with the sequence below.
What is the correct 747 cold-and-dark start sequence?
The correct order is electrical power, inertial alignment, APU, fuel and pneumatics, engine rotation, fuel introduction, then after-start configuration.
- Load a genuine cold-and-dark state. Start at a gate or parking stand rather than on a runway. Apply the parking brake, fit wheel chocks if the aircraft supports them, set all four thrust levers to idle and confirm the four fuel control switches are at
CUTOFF. Some add-ons require their own panel-state menu; simply shutting down an already running aircraft may leave valves and electrical buses configured. - Establish electrical power. Switch the battery on and set standby power as the model requires. If ground power shows available, connect it. Otherwise, use battery power only long enough to start the APU; a battery alone is not the normal source for an extended cockpit setup.
- Begin inertial alignment. Set the IRS selectors to
NAVand enter or confirm the aircraft position through the FMC/CDU if the simulation models this. Alignment can continue while you prepare the aircraft and is not normally required merely to achieve engine light-off, but it must be complete before navigation displays and route guidance work correctly. - Start the APU. Move the APU control through
STARTas represented by the aircraft, then wait for a stable running indication and generator availability. Connect the APU generator or generators before removing external power. Do not rush this stage: the APU must be running before it can provide starter air. - Configure the fuel and hydraulic systems. Check that fuel is present in the expected tanks, then switch on pumps only for tanks containing usable fuel. A mistake we see constantly is turning on every centre-tank pump despite an empty or nearly empty centre tank, which creates avoidable pressure warnings. Set hydraulic demand pumps to the aircraft checklist's pre-start position.
- Provide pneumatic starter air. Select APU bleed air and configure the isolation valves and packs according to the model-specific checklist. If starter-air pressure is marginal, switching the air-conditioning packs off reduces demand and is a useful troubleshooting step.
- Prepare for engine start. Turn on the red anti-collision beacon and confirm that doors are closed, ground equipment is clear and pushback is under control. Engine numbers run from left to right as viewed from the cockpit: number 1 is the left outboard engine and number 4 is the right outboard engine.
- Crank the selected engine. Pull or turn its start selector to
START. Confirm that the start valve opens and N2 begins increasing. At maximum motoring speed—and never below the minimum N2 specified by that aircraft's checklist—move the corresponding fuel control switch fromCUTOFFtoRUN. - Monitor the start. Look for EGT rise, increasing oil pressure and continued N1/N2 acceleration. The starter should disengage automatically as the engine becomes self-sustaining. Let the engine stabilise before starting the next one unless the model's checklist specifically permits paired starts. The commonly used order varies by operator and add-on, so follow the supplied sequence rather than assuming that every 747 starts 4-3-2-1.
- Complete the after-start flow. Verify all four engine generators are online, set hydraulic pumps and air-conditioning packs for normal operation, configure engine bleeds and isolation valves, then check the EICAS for warnings. Set flaps, trim, anti-ice and transponder as required for departure.
For the Microsoft Flight Simulator 747-8, our model-specific 747-8 cold-and-dark sequence covers its electrical, APU, fuel and bleed-air controls in greater detail.
Why will the Boeing 747 engines not start?
A 747 engine usually fails to start because starter air, fuel or electrical power is missing, or because a controller binding is overriding a cockpit switch.
| Symptom | Likely cause | What to check |
|---|---|---|
| No cockpit power | Battery, standby power or selected power source is off | Connect available external power or start the APU and select its generators. |
| APU runs but N2 stays at zero | No pneumatic starter air | Check APU bleed, isolation valves and the engine start selector. Temporarily turn packs off if air pressure is low. |
| N2 rises but there is no EGT rise | Fuel has not been introduced | Confirm the correct fuel control is at RUN, the relevant pumps are on and the tank contains fuel. |
| Fuel control returns to cutoff | Conflicting hardware or assistance binding | Remove duplicate mixture, condition-lever and fuel-cutoff assignments, then disable automated starting assistance. |
| EGT rises but N2 stops accelerating | Hung or weak start | Return the fuel control to CUTOFF, allow the engine to spool down, restore adequate bleed air and retry. |
| Displays lose power when the APU is stopped | Engine generators are not supplying the buses | Reconnect the APU, verify each engine generator and correct the electrical configuration before another shutdown attempt. |
| Navigation displays remain incomplete | IRS alignment or position entry is unfinished | Set all required IRS selectors to NAV, enter the present position and wait for alignment. |
If one engine starts and another does not, compare their overhead-panel indications switch by switch. That usually reveals a closed bleed valve, unselected fuel pump or the wrong fuel control more quickly than restarting the whole simulator.
Does the procedure change between the 747-400 and 747-8?
The 747-400 and 747-8 use the same power-air-rotation-fuel principle, but their panel layouts, system logic and automation are not interchangeable.
A simplified default aircraft may omit fire tests, electrical-source logic, realistic IRS delays or abnormal starts. A study-level add-on may require every bus, valve and pump to be configured correctly. FSX users flying the default older model can follow our downloadable phase-by-phase 747-400 checklist; do not apply its individual switch positions blindly to a 747-8.
If the basic relationship between battery power, APU generation and bleed air is unfamiliar, our panel-by-panel cold-and-dark guide for Microsoft Flight Simulator explains the same flow across several aircraft.
When should you shut down the APU?
Shut down the APU only after all running engines are stable, their generators are powering the electrical buses and the engine bleed-air system can support the packs.
Remove the APU's electrical and pneumatic loads first, allow any cool-down period modelled by the add-on, then move the APU control to off. Keep it running if an engine generator or bleed source is unavailable; otherwise, stopping it too early can produce a dark cockpit, weak pack airflow or another engine failing to start.