 The design, which was designated as the Laté 520, was a large sesquiplane, comprising a central double-decked hull and a pair of stub wings, somewhat resembling the smaller Latécoère 300.Weighing roughly 37 tonnes when loaded and 17 tonnes empty, it was the largest aircraft to be manufactured by French industry at that time.In flight, it possessed a maximum range of 2,800 miles between refuelling stops.