Very scary when flying - rather on the large side.
Featured snippet from the web
"Robber flies are not normally considered pests. They will occasionally bite humans, but they are not blood feeders, and will only bite on accident or if provoked. Because they feed on other insects, robber flies are generally considered beneficial."
This is a beauty, not one I have seen up this way. Excellent sharp shot of it. It is true that they feed exclusively on other insects, some specialize in particular types of insects too, so they will only bite us if provoked or feel in danger, but it is rare. V