Caps, maybe. Beanies, no. I haven't seen a grown man in a beanie in 40 years.
I have just learned that the language has moved on somewhat in the years since I stopped paying attention.
In the parlance of our time, a “beanie” is something quite different from what I know as a beanie; a beanie is now what we used to call a “watch cap” in my time.
It’s just not the same without the propeller, I’ve got to say.