Definition
A short, rigid antenna whose physical length is much less than a quarter-wavelength of the radio frequency it transmits or receives. Because it is electrically short, it is typically used for higher-frequency communications (such as VHF or UHF) where even a short physical element is electrically efficient, and it is mounted directly to the aircraft skin which acts as the ground plane.
Plain English
A short, stiff antenna sticking out of the aircraft. It works well at high radio frequencies because the radio waves are short, so the antenna can be short too.
Context Anchor
Seen during preflight inspection on the aircraft exterior and in avionics installation or maintenance discussions.
Derivation
From the English 'stub,' meaning a short, blunt remainder or stump. The name simply describes its appearance — a short stump-like protrusion compared to longer wire or whip antennas.
Why Pilots Care
Provides reliable VHF radio range with very little added drag or weight.
Intuition Check
A stub antenna is not a broken-off antenna. In this context, “stub” means a deliberately short antenna designed for the aircraft system it serves.
Example Sentence 1
During the walk-around, the pilot checked that the VHF stub antenna on top of the fuselage was secure and undamaged.
Example Sentence 2
After switching to the backup radio, the student noticed the signal improved because the stub antenna had better line-of-sight.