Manually start the default Boeing 737 in FSX with the correct battery, APU, bleed-air, fuel and starter sequence, plus fixes when N2 will not rise.
To manually start the default Boeing 737-800 in FSX or FSX: Steam Edition, power the aircraft with the battery and APU, connect the APU generators, switch on fuel pumps and APU bleed air, then crank each engine in GRD and move its fuel control lever to IDLE once N2 reaches about 20–25%.
The default 737 models these systems more simply than a study-level add-on, but its overhead panel, starter switches and fuel control levers support a recognisable manual start.
What should be set before starting the FSX 737?
The aircraft needs electrical power, fuel and a source of pneumatic starter air before either engine will turn.
- Secure the aircraft: set the parking brake, place both throttles at idle and check that both engine fuel control levers are at CUTOFF.
- Switch on electrical power: turn the battery ON and set standby power to AUTO.
- Start the APU: move the APU switch to START and release it. It should return to ON; wait until the APU is running steadily and generator power is available.
- Connect APU power: operate both APU generator switches so the APU supplies the electrical buses.
- Configure the fuel system: switch on the main tank fuel pumps. Use the centre tank pumps only when that tank contains fuel.
- Configure bleed air: put APU BLEED ON, leave the engine bleed switches ON, set the isolation valve to AUTO and switch both air-conditioning packs OFF for the start.
If every panel is completely unpowered, our 737-specific cold-and-dark power-up sequence explains the electrical setup that comes before these engine-start steps.
How do I start each engine manually?
Start one engine at a time, normally engine 2 first, and do not introduce fuel until its N2 compressor indication is rising.
- Crank engine 2: move the right ENGINE START switch to GRD.
- Watch N2: confirm the engine is rotating and wait until N2 reaches approximately 20–25%.
- Introduce fuel: move engine 2's fuel control or start lever from CUTOFF to IDLE.
- Monitor the start: look for rising EGT, N1 and oil pressure. The engine should accelerate to a stable idle, and the start switch should release from GRD automatically.
- Start engine 1: repeat the same sequence with the left starter switch and engine 1 fuel control lever.
- Transfer the services: connect both engine generators, return the packs to their normal operating setting, switch APU BLEED off and shut down the APU after a short unloaded cooling period.
Finish by checking the hydraulic pumps, probe heat and other before-taxi items. FSX will not enforce every real 737 checklist dependency, so a running engine does not mean the aircraft is fully configured for departure.
Why won't the default FSX 737 engines start?
A manual start usually fails because starter air is missing or fuel is introduced at the wrong point.
| Symptom | Likely cause and fix |
|---|---|
| N2 remains at zero | The starter has no pneumatic air. Wait for the APU to stabilise, confirm APU BLEED is ON, switch the packs OFF and check the isolation valve before selecting GRD again. |
| N2 rises but there is no EGT | Fuel has not reached the engine. Check fuel quantity and pumps, then move the correct fuel control lever from CUTOFF to IDLE at 20–25% N2. |
| The engine lights and then dies | Confirm the fuel lever stayed at IDLE, the relevant main tank contains fuel and its pumps are on. |
| The cockpit switches appear out of sync | FSX may have inherited control positions from the saved default flight. Return the fuel levers to CUTOFF, reset the switches and start the sequence again. |
Ctrl+E performs FSX's automatic engine start and is useful as a diagnostic, but it bypasses the manual procedure. Our FSX keyboard-command reference lists the related engine and fuel controls if a cockpit lever is difficult to operate.
How do I make the default 737 load cold and dark?
FSX normally inherits switch and engine states from its saved default flight rather than forcing the 737 to start cold and dark.
You can shut down the aircraft completely, save that flight and use it as your starting state. For a prepared alternative, the powered-down cockpit setup for FSX is designed for practising apron power-up and manual starts.