Definition
Electrical power supplied by a current that flows steadily in one direction at a constant voltage. In aircraft, DC power is typically produced by the battery and by generators or alternators (whose AC output is rectified to DC), and it is distributed through the aircraft's electrical bus to operate avionics, lighting, instruments, and engine starting systems.
Plain English
Electricity that flows one way only, at a steady push, like the power from a battery. Most small aircraft run on this kind of power.
Context Anchor
Seen in aircraft electrical system descriptions, cockpit power checks, equipment manuals, and abnormal checklists involving the battery or charging system.
Derivation
Direct Current is called 'direct' because the electrons travel directly from one terminal to the other without reversing. This contrasts with Alternating Current (AC), where the flow reverses direction many times per second.
Why Pilots Care
Loss of DC power can disable critical flight instruments, communications, and navigation, forcing immediate use of backup systems or emergency procedures.
Analogy
A flashlight battery supplies DC power: the positive and negative ends stay the same, and the electricity flows one way through the bulb.
Intuition Check
Do not read “power” here as engine power or thrust. Dc Power means electrical power supplied by direct current.
Example Sentence 1
The aircraft battery supplies 24-volt DC power to the starter when the engine is cranked.
Example Sentence 2
A short in the DC power circuit caused several cockpit instruments to go dark.