Which statement is true about primary DC power sourcing?

Which statement is true about primary DC power sourcing?

• A. The #1 and #2 Main Generators
• B. The #1 and #2 Converters
• C. APU Generator
• D. External Power

Answer: (B)

The main idea is that DC power for the helicopter’s essential systems is produced by dedicated DC power converters rather than directly by the generators or by the APU or external power. In normal operation, the #1 and #2 main generators supply AC power, and two DC power converters take that AC and convert it to a stable 28 V DC to feed the DC buses. This redundancy keeps the avionics powered even if one converter or generator drops out. The APU generator and external power can supply power as alternatives, but they are not the primary DC source during standard operation. The battery provides DC power only for emergency or critical loads if both converters fail.

The main idea is that DC power for the helicopter’s essential systems is produced by dedicated DC power converters rather than directly by the generators or by the APU or external power. In normal operation, the #1 and #2 main generators supply AC power, and two DC power converters take that AC and convert it to a stable 28 V DC to feed the DC buses. This redundancy keeps the avionics powered even if one converter or generator drops out. The APU generator and external power can supply power as alternatives, but they are not the primary DC source during standard operation. The battery provides DC power only for emergency or critical loads if both converters fail.