02/28/2016. Remarks by Kees Kort: "The Dufaux brothers, Henri and Armand were early aviators originating from Geneva, Switzerland. The two brothers were a less likely duo to make it in aviation as Henri was an artist (painter) and Armand was a technician. After some early developments, a helicopter and a tandem triplane (nine wings in all) they went to work on more conventional tractor biplanes. Several designs were actually built and flown.

This fourth design in the biplane series, hence the Dufaux IV, was a classic looking biplane with uncovered fuselage and ailerons in between the wings. Characteristic landing gear with a long skid in the middle, to prevent nosing over in the case of a hard landing or an uneven airfield. The design appeared in 1910. The Dufaux IV was fitted with several engines - an Anzani radial, a Gnome rotary rated at 50 hp and a 60 hp Amtoinette ENV eight-cylinder liquid-cooled V-engine.

Armand Dufaux flew the Dufaux IV over the length of Lake of Geneva on August 28, 1910, winning the prize of 5,000 Suisse francs promised by a Geneva firm for the first to complete this flight. The flight from Noville to Geneva, a distance of 49.7 mls (80 km), was accomplished in 56 min 5 sec at an average speed of 53.2 mph (85.6 kmh). The unique Dufaux IV (fitted with the ENV engine) is preserved in the Swiss Museum of Transport "Verkehrshaus der Schweiz" in Luzern."