Definition
An electrical cable in which a single central conductor is surrounded by an insulating layer, then by a tubular conducting shield (often braided wire), and finally by an outer protective jacket. The center conductor and the shield share the same central axis, which is what makes the cable 'coaxial.' This construction is used to carry high-frequency radio signals with minimal loss and minimal interference from outside electrical noise.
Plain English
A special wire used to carry radio signals. It has a wire down the middle, a layer of insulation around it, and a metal shield around that. The shield protects the signal from outside electrical interference.
Context Anchor
Seen in aircraft radio, navigation, and antenna installations, especially where a cable connects a radio unit to an antenna.
Derivation
From the Latin 'co-' meaning 'together' and 'axis' meaning 'central line.' The name describes the construction: the inner wire and the outer shield share the same central axis, one inside the other.
Why Pilots Care
Reliable coaxial cables are essential for clear communication and accurate navigation signals; damaged cable can cause weak transmissions or complete loss of radio and transponder function.
Analogy
Think of it like a wire running through the center of a protective metal tube. The inside wire carries the signal, and the outside layer helps guard it from electrical noise.
Intuition Check
Do not think of coaxial cable as just any electrical wire. In aviation, it usually means a shielded cable made to carry radio signals cleanly between equipment and an antenna.
Example Sentence 1
The avionics technician replaced the coaxial cable running from the transponder to its belly antenna after intermittent signal loss was reported.
Example Sentence 2
During the preflight, the pilot checked the coaxial cable connections at the GPS antenna for corrosion.