"Air ship" is an apt term, since that it has sails and a prow and a keel and portholes. The story notes that Frank was famous for his electric ships and electric horses, and makes no mention of previous airships.
I wonder if he dispatched company assassins to eliminate everyone who talked about his previous airships. I mean, they were national sensations, seen by all, but we're expected to just forget they existed.
So what are the technical specs on this one? I believe they operate upon the Storage Principle:
Until the next time the plot requires a flying ship, and someone says "Well, let's take the Flash," and Frank gives him a long, cold look.