[starpilot]

Hummingbirds flap their wings at 60 Hz or they drop like a rock. Some flying birds cannot glide at all. Flap frequency is directly related to the size of the bird, so that there's optimal matching of Reynolds number effects.

[YeGoblynQueenne]

I don't know what Reynolds number effects are.

Hummingbirds are a special case, if I understand correctly; they fly like insects, most of which can't glide.

So maybe the analogy about planes should be with insects, not birds? "Planes don't flap their wings like insects".