Aviation & Real-World Flying 6 min read

How do you start a Douglas DC-3 cold and dark?

Ian Stephens
In short

Start a Douglas DC-3 cold and dark with the correct fuel, propeller, mixture, primer and radial-engine sequence, plus fixes for failed starts.

To start a Douglas DC-3 from cold and dark in a flight simulator, secure the aircraft, switch on battery power, select the main fuel tanks, set propellers to high RPM, prime as required, crank the first engine with ignition on, introduce mixture according to the model’s checklist, confirm oil pressure, then repeat.

This Aviation & Real-World Flying answer is a simulator flow, not an approved procedure for operating a preserved aircraft. Real DC-3 variants, engine installations and starting systems differ, and an actual start requires trained crew, the aircraft’s approved checklist and suitable fire cover.

Simulator implementations differ too. The default FSX aircraft is best used with its downloadable DC-3 cockpit manual and checklist, while the FS2004 DC-3C package includes detailed operating guidance. Some add-ons automate the booster coil or primer; others model every switch.

DC-3 cold-and-dark start sequence

Use this sequence as the baseline, but let the checklist supplied with your particular DC-3 decide the exact mixture timing, primer quantity and starter operation.

  1. Secure the aircraft. Set the parking brake or chocks, place the landing gear control down, confirm the throttles are near idle and switch off unnecessary electrical loads. Open the cowl flaps and set carburettor heat cold.
  2. Check for a simulated hydraulic lock. Persistent-state or high-fidelity radial-engine models may require a preflight propeller pull-through after prolonged parking. Use the add-on’s maintenance or preflight function; never treat hand-turning a real propeller as a casual procedure.
  3. Configure the fuel system. Check that fuel is aboard, select the main or specified start tanks and leave crossfeed in its normal position unless the checklist says otherwise. An empty selected tank is a common reason for an apparently correct start failing.
  4. Set the engine controls. Move both propeller levers to high RPM or full fine. Start with mixtures at idle cut-off and crack the throttles slightly. Some simplified DC-3 models instead require AUTO RICH before cranking, so follow their documentation rather than forcing real-aircraft logic onto them.
  5. Apply electrical power. Turn on the battery or master switch and the beacon if it is modelled. Use external power when the add-on provides it and the battery cannot maintain cranking speed.
  6. Build fuel pressure and prime. Select the first engine, operate its booster pump and confirm fuel pressure. Prime only as required for the simulated temperature and engine state; a genuinely cold radial needs more prime than an engine stopped a few minutes earlier.
  7. Crank and apply ignition. Confirm the propeller area is clear. Operate the starter, using separate energise and engage controls if the model provides them, and apply BOTH magnetos or the booster coil when its checklist calls for ignition.
  8. Introduce mixture. In detailed radial simulations, move the mixture from idle cut-off to AUTO RICH as the cylinders begin firing. If the supplied checklist specifies AUTO RICH before starter engagement, use that sequence instead.
  9. Stabilise the engine. Release the starter once the engine is running and set the lowest smooth speed specified by the checklist, commonly around 800–1,000 RPM. Confirm oil pressure rises promptly and remains within the model’s marked limits; shut down if it does not.
  10. Start the second engine. Repeat the fuel-pressure, prime, starter and mixture sequence. Bring generators and other electrical loads online only as the aircraft checklist directs.

Which DC-3 engine should be started first?

Start the right engine first when the checklist specifies the conventional right-then-left order, but the radial engines themselves do not require that sequence.

Many DC-3 procedures use the right engine first because it suits normal ground handling and keeps activity away from the left-side passenger and service area. A converted aircraft or simulator add-on may specify the opposite order, particularly when ground equipment, hydraulic systems or custom cockpit logic are modelled.

Why does the DC-3 crank but not start?

A cranking DC-3 normally fails to fire because fuel pressure, priming, ignition or mixture timing is wrong rather than because the starter is defective.

SymptomLikely causeWhat to check
No propeller movementNo battery or external power, wrong engine selected, or starter control not engagingCheck the master switch, voltage, engine selector and conflicting starter bindings.
Propeller turns but nothing firesFuel selector closed, no boost-pump pressure, insufficient prime, magnetos off or booster coil omittedVerify the selected tank contains fuel, confirm pressure and repeat the checklist without adding excessive prime.
Engine fires and immediately stopsMixture remains at idle cut-off, throttle is fully closed or fuel pressure disappearsSet AUTO RICH at the required point, crack the throttle and keep the boost pump on until the checklist permits it off.
Rough firing, smoke or backfiringOver-priming, mixture too rich or a cold, fouled radialStop adding fuel and use the model’s flooded-engine clearing procedure.
Only automatic start worksThe add-on uses custom cockpit logic or an assistance option is overriding switchesUse the virtual-cockpit controls, inspect duplicate mixture and magneto assignments, and disable conflicting automation.
Engine runs without oil pressureIncorrect configuration, simulated damage or a model faultShut the engine down rather than increasing RPM and investigate the aircraft’s maintenance or failure settings.

How do you clear an over-primed DC-3 engine?

For a simulated flooded start, return the mixture to idle cut-off, switch off the booster pump and use the model’s specified throttle and cranking procedure until excess fuel clears. Do not keep priming or hold the starter beyond its permitted duty cycle.

If the engine still will not fire or stay running, our fuel, mixture, ignition and control-binding checks for failed MSFS starts cover the next diagnostic steps.

What checks come after both DC-3 engines start?

After both engines are running, confirm lubrication, fuel, charging and hydraulic indications before switching on the remaining systems or applying taxi power.

  • Keep both engines at a smooth warm-up RPM and watch oil pressure and temperature.
  • Confirm fuel pressure, generator output and battery charging.
  • Set booster pumps as required by the aircraft checklist rather than switching them off automatically.
  • Check hydraulic or pneumatic pressure if the model simulates those systems.
  • Bring radios, navigation equipment, lights and other electrical loads online in stages.
  • Leave cowl flaps open for ground operation unless the checklist specifies another position.
  • Do not apply high power to a cold radial engine; wait for the minimum oil-temperature indication specified by the model.
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