DC-3 Engine Run Checklist

Photo Courtesy of Bill Rambow.

DC-3 Mechanic's Engine Run checklist Ver 3, 06 Jun 99, from North Central Maint. Manual, 16 Apr 65 edition


1. Bird nests: Check in Rudder hinges, Aileron Hinges, Carb Airscoop, Cylinders. Check lower cowl for trash.

2. Cowl latches: secure, Cowl flaps open.

3. Gear Pins in?

4. Props: walk through 12 blades.

5. Battery cart: plugged in, clear of props?

6. Gust locks: Elevators free!, ailerons and rudder optional.

Cockpit Set-up

1. Parking brake set, pressure up (at least 500 psi)

2. Hydraulic Quantity: Pressure up, sight glass low.

3. Mags Off

4. Battery Selector: Battery Cart, "Do Not Taxi" light on?

5. Mixture: Idle/Cutoff

6. Fuel tank selectors: Choose your tank.

7. Props: "Forward For Fine Pitch" (low pitch, high RPM)

8. Throttles: open 1/2 inch

9. Carb heat : cold

10. Landing Gear: neutral, Latch Handle down.

11. Flaps: Up, Handle neutral

12. Firewall Shutoff: It's still in the Open position?

13. Cowl Flaps: Full Open, selected off?

14. Fuel Boost pumps: On, 14 psi? , prime pressure drop?

15. Magneto Master Button: In?, Left and Right switches off?

Engine Start:

1. Clear Prop, response

2. Palm Switch, get ready to do a 3 finger Chord

3. Crank Starter: middle finger.

4. 6 Blades: Mags On Both Mags on: Ignition Booster on (ring finger)

5. Prime at one second intervals (index finger)

7. As engine fires up, Release Starter. Mixture to Auto Rich, occasional prime. Release Ignition Booster

8. Oil Pressure: indicating within 30 seconds

9. RPM: less than 800 until oil pressure established.

Idle Checks:

A. Engine Fuel Pump pressure: Switch off boost pumps. Low pressure lights off?

B. Vacuum gauge: Above 2, near 5 inches Mercury. Flight Instruments coming to life?

C. Oil Pressure: lights off, pressure coming down as engine warms up. Oil temp coming up? 40 Celsius is good.

D. Generator Cut in: At about 1300-1400 RPM. Switch to Ship's Battery, watch amps. No Voltmeter in cockpit. Ours in on the Radio Rack, with the Circuit Breakers, for field flashing.

E. Carb Heat: does it rise?

F. Cycle prop: Oil Temp above 40 Celsius? RPM above 1200?

G. Hydraulic pressure: Got some?

H. Note idle Manifold Pressure, Idle speed 500 rpm.

Mag Checks are done at Field Barometric pressure.......30 inches mercury. 40 Rpm drop on one mag is normal, more than 65 RPM is out of limits. Look for 2350 RPM +/- 50. Wind factor 2 rpm per mph.

Engine Burnout for Wright engines:

Mixture: Auto Rich, Prop: Full forward (high RPM)

Yoke: Pull it back and hold it to keep the tail down.

Throttle: Advance to 36 inches Manifold Pressure, 1 second per 100 RPM. Retard to idle, hold 15 seconds. Advance to 36 inches ( in a 10 second count) Back to Field Barometric Pressure

Mags: check RPM drop.

note: after burnout, use auto-lean for operation below 1600 RPM.

Shut Down:

1. Check Vacuum gauge as each engine is shut down.

2. Check hydraulic pressure after first engine is shut down. Cycle flaps to check if second engine Hydraulic pump is working.

3. RPM: Check for 10 RPM rise from idle speed when mixture is cut off.

4. Check Fuel, Oil, Vacuum lights come on during shutdown.

I read down the checklist and wanted to explain a few items, in the way I worded them for my convenience, and, so I could get it all on a page.

The "Do Not Taxi" light is a holdover from my 727 class. If the External Power / Battery Cart is plugged in (even if it's not selected) an amber light comes on above the mag switch. If the light is on, "Do Not Taxi". You'll hurt something, you're still plugged in. "Hydraulic pressure up, sight glass low": When the hydraulics are pumped up, the level in the sight gauge decreases. All the Douglas airplanes I've played with have a noticable volume decrease as pressure comes up. I'm reminding myself to make sure we don't run out of red juice. Just to be safe, "Parking Brake Set? Pressure Up?" An airplane rolling away unexpectedly IS scary. The "3 finger chord" refers to the way our engine selector switch is set up. We have a gang bar connecting a trio of 3 position switches. The gang bar selects the left or right engine. With my palm I push right, or pull left to direct my starter / ignition booster/ primer efforts to the Captain's, or Copilot's engine. Ok, so the palm of my right selects the engine, then the 3 middle fingers play the switches. Any radial engine-run mechanic develops the skill. "Mags On, Ign Booster On" once the mags are on, hold down the Ignition Booster. It delivers a shower of sparks to the forward spark plugs for starting.

This page was written by "Buzz" Meyer.

The following is a COMPLETE Check List for the DC-3...