The Boulton and Paul "Sidestrand I" bomber airplane (British)
This NACA aircraft circular from 1928, issued by the NASA Technical Reports Server, documents the British Boulton and Paul Sidestrand I twin-engine bomber through reference drawings and technical sketches. Its pictures are line drawings of airframe structure, engine mountings, and fittings, showing clean hatched outlines and numbered callouts that a designer could use as a model for mechanical diagrams and technical illustration layouts.
