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Section 3034                  GROUND TESTING ENGINES

B. INTERMEDIATE RPM CHECK (cont'd)

GR-1820G-102                                   R-1830-92

3. Landing lights should be turned on individually and ammeters checked to make certain that the increased load due to landing lights causes ammeter to indicate increased charging rate. This will indicate whether generators are charging properly.

4. Generator system voltage shall be checked by pushing small buttons immediately below ammeter.

Reading should be 13 to 14.3. volts. | Reading should be 26 to 28.5 volts.

5. Check de-icer operating pressure should read 7 1/2-8 psi.

C. INDIVIDUAL ENGINE CHECKS

1. Open right engine to 25" manifold pressure which will give an engine speed of approximately 1700 RPM. | Open right engine to 25" manifold pressure which will give an engine speed of approximately 1900 RPM.

2. Check oil pressure for 60-65 psi. | Check oil pressure for 80-100 psi.

3. Check fuel pressure for 5-6 psi. | Check fuel pressure for 14-16 psi.

4. Move propeller control to high pitch position noting smoothness of governing action, speed of pitch change and movement through full range of RPM travel. Engine speed should drop at least 300 to 500 RPM. NOTE: If governing action is not smooth it may be necessary to operate the propeller through its full range of travel several times to eliminate air from the propeller dome.

5. Move the carburetor heat control to the Full Hot position long enough to note proper action as indicated by a rise in carburetor mixture temperature and return immediately to the Full Cold position.

6. Operate carburetor anti-icers (alcohol) while carburetor heat is applied. A sudden drop in temperature due to the cooling effect of the alcohol when sprayed into the airstream indicates that the carburetor alcohol system is functioning properly.

7. Check for RPM drop and smooth running when operating on each magneto alone. Operate on a single magneto for as short a time as possible to permit the engine speed to stabilize. In switching from "BOTH" to either "Left" or "right" the normal drop-off is 50 to 75 RPM and does not usually exceed 100 RPM. When switching from "Left" to "Right" or from "Right" to "Left", the change in RPM should not be more than 30 to 40.

1/15/46                    
DC-3 GROUND OPERATION
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