The Latecoere 521 "Lieutenant De Vaisseau Paris" commercial flying boat (French) : a two-deck six-engine semicantilever sesquiplane
This is a 1936 NACA aircraft circular issued by the National Advisory Committee for Aeronautics, describing the French Latecoere 521 Lieutenant de Vaisseau Paris six-engine flying boat for an engineering readership. The record names the source only as NASA Technical Reports Server, so the publisher's wording is left to the scans. The pictures are black-and-white photographs and drawings of the hull interior, wing structure, and rigging, with plan and perspective line drawings, which a designer could use as references for lattice framing, braced structure, and dense mechanical detail.
