Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
What is this protrusion on the tail of Learjet 24D (shown just above the avro museum logo) and what is its function?
Learjet 24D Tail closeup
Zoomed out image of the Learjet tail
Source: images were taken by yours truly
It's a VOR antenna. You can find more information about it in similar questions like this one or this one.
Required, but never shown