2013 - 100th Anniversary of the First practical Monocoque Fuselage Design

Even though that the first practical monocoque fuselage equipped plane flew in 1913, did you know that critics deemed it 15 years ahead of its time?

By: Ringo Bones

When the first practical monocoque fuselage equipped plane – the Deperdussin - flew 100 years ago and then set the 1913 aircraft world speed record of 127 miles per hour as it was piloted by Maurice Prévost, critics deemed it too radical. And in truth, the aeronautical design has engineering principles that didn’t become standard 15 years later. But did the plane’s introduction hasten the advancement of airplane design that’s sadly lacking in the world of space exploration?

The monocoque fuselage permitted the fuselage’s skin or shell, rather than the aircraft’s frame, to carry the loads and stresses of flight. In the matter of fuselages, most of the early structures before and a few years after the Wright Brothers’ first successful airplane flight were simply kite-like frames designed to hold together the various components of the airplane. By 1912, however, engine power was increasing, along with speeds, altitudes and maneuverability – all creating greater loads on the fuselage. In that year a great innovation appeared – the so-called monocoque structure. “Monocoque”, from the Greek monos and the French coque, means “single shell”.  In the pure monocoque structure, there is no internal bracing; the shell bears all the loads and because it is in the basic shape of a tube, it has enormous strength. In later years this approach was modified to the semimonocoque design, which had stiffeners running the length of the fuselage. Engineers also used the term “stressed skin” construction because even though there is internal bracing, the skin bears most of the flight loads.

The first application of monocoque construction came from the drawing board of a French designer M. L. Béchereau; the airplane itself was built of molded wood by the aircraft works of Jules Deperdussin, a famous plane maker of the time. The fuselage was molded in two halves, which were fitted together. In addition to structural strength, the rounded, streamlined shape provided an aerodynamic bonus in lower drag, and in Chicago on September 9, 1912, the Deperdussin monoplane set its first – and a new - world’s speed record of 108 miles per hour. And despite setting another world speed record in 1913, it wasn’t until 15 years later – around the late 1920s – that the monocoque fuselage construction became universally accepted as a standard principle in aircraft construction.