Definition
An electrical discharge that jumps across a gap between two carbon electrodes, producing intense heat and a brilliant white light. The arc is sustained by ionized gas between the electrode tips and is used in welding, high-intensity lighting, and certain aircraft maintenance processes.
Plain English
A bright, very hot spark that flows continuously between two pieces of carbon when electricity jumps the gap between them.
Context Anchor
Seen in older aircraft lighting references and in maintenance discussions involving arc lamps, welding, or cutting equipment.
Derivation
Carbon refers to the material of the electrodes (rods made of carbon, which can withstand extreme heat). Arc comes from the Latin arcus meaning bow or curve — describing the visible curved shape of the electrical discharge as it bridges the gap between the two electrodes.
Why Pilots Care
A carbon arc can be extremely bright and hot, so it is treated as a burn, fire, and eye-injury hazard during maintenance.
Intuition Check
A carbon arc is not an arc-shaped piece of carbon. It is electricity jumping between carbon electrodes and making intense light and heat.
Example Sentence 1
The mechanic used a carbon arc torch to cut through the corroded steel bracket during the airframe repair.
Example Sentence 2
Older aircraft used carbon arc lamps for powerful forward illumination on the ramp.