Definition
The accumulation of ice on an aircraft's external antennas during flight in icing conditions. Because antennas protrude into the airflow and are usually unheated, they collect ice readily. Ice buildup distorts the antenna's shape and electrical characteristics, which can weaken or block radio signals, degrade navigation reception, and cause vibration or even structural failure of the antenna itself.
Plain English
Ice forming on the small rods, blades, and wires sticking out of the aircraft that send and receive radio signals. When ice covers them, communication and navigation equipment can become unreliable or stop working properly.
Context Anchor
Seen in instrument flying when the aircraft is in below-freezing cloud or precipitation and radio or navigation signals begin to weaken or become unreliable.
Derivation
Antenna comes from a Latin word for a sail yard, later used for an insect’s feeler, and then for a device that sends or receives radio signals. Icing means ice forming on a surface. Together, antenna icing means ice forming on the signal-receiving or signal-sending parts of the aircraft.
Why Pilots Care
Ice on antennas can weaken or block radio signals, causing loss of navigation guidance and air traffic control contact.
Grounding Statement
Even a thin layer of ice on a small antenna can make a previously clear signal fade or become unreliable.
Intuition Check
Antenna icing is not just ice near an antenna. It means ice on the antenna itself, where it can interfere with the aircraft’s radio or navigation signals.
Example Sentence 1
After twenty minutes in freezing rain, the pilot noticed garbled radio transmissions and suspected antenna icing.
Example Sentence 2
ATC reported weak transmissions once antenna icing began to affect the comm radios.