The PB2Y had an interesting feature known to other four-engine flying boats. The Coronado had four-bladed propellers on the inboard (typically No. 2 and 3 engines) mounts. The outboard had three-bladed propellers on the outboard engine mounts.
Other features of the Coronado That it had in common with the PBY Catalina was the retracting wing stabilization floats that once folded up, became part of the wingtips. This was a feature on the PBY Catalina also produced by Consolidated, the company also known for the B-24 Liberator. - David P. Murphy