Definition
A faint luminous electrical discharge that appears around a conductor, antenna, or sharp metal point when the surrounding air becomes ionized by a strong electric field. In aviation, corona discharge commonly occurs on aircraft surfaces during flight through precipitation or charged atmospheric conditions and can cause radio interference if not bled off through static dischargers.
Plain English
A weak, glowing electrical leak from a sharp edge or point on the airplane when the air around it gets electrically charged. It's quiet and usually invisible in daylight, but it can produce static that disrupts radio reception.
Context Anchor
Seen in discussions of aircraft electrical effects, static electricity, thunderstorms, antennas, and high-voltage ignition wiring.
Derivation
From the Latin corona, meaning 'crown' or 'wreath.' The name was given because the faint glow forms a halo or crown-like ring around the charged point. Knowing this helps the term stick: it describes the shape of the visible discharge.
Why Pilots Care
Signals strong electrical activity that may cause radio interference or indicate nearby lightning risk.
Grounding Statement
Picture a faint blue glow or crackle forming around a sharp metal point when the surrounding air becomes electrically charged.
Intuition Check
Corona does not mean the Sun’s outer atmosphere here. In aviation use, it means an electrical glow or discharge in the air around a charged object.
Example Sentence 1
Flying through heavy snow, the pilot heard rising static in the headset caused by corona discharge from the airframe.
Example Sentence 2
Static wicks help prevent corona from building up and disrupting the radios.