Humbert Tétras
The Humbert Tétras (English: "Grouse") is a French two seat ultralight with a single engine and high wing. Available as a kit or complete aircraft, it has been in production since 1994 by Humbert Aviation of Ramonchamp. Design and development. The Tétras was first seen in public in 1992 at the RSA Rally at Moulins and marketing began in 1994. It is a conventionally laid out single engine, tractor configuration light aircraft with a high wing, side-by-side seating for two and a fixed undercarriage. Its straight non tapered wing is a composite structure, with an aluminium  frame, Styrofoam filling and fabric covering. The ailerons and three-position flaps are made of aluminium. The wings are braced on each side with a single lift strut to a lower fuselage longeron. The tailplane, mounted at mid-fuselage height, is also strut braced. The fuselage of the Tétras is a steel structure covered with Dacron. Variants with both tricycle and conventional undercarriages, all fixed, have been built. The former arrangement has spring cantilever main legs, the latter has the mainwheels mounted on faired V-strut legs and bungee sprung half axles fixed to a compression frame. Both undercarriage variants  have hydraulic brakes. Skis may also be fitted. The Tétras has been fitted with a variety of engines; originally the 54 kW (72 hp) Humbert-Volkswagen HW 2000 was used. More recently two flat fours from the Rotax range, the 60 kW (80 hp) 912 UL or the 74 kW (98 hp) 912 ULS, have become standard choices. Operational history. About 150 Tétras appeared on the French ultralight register in October 2010. The French "Centre d'Essais en Vol" have tested the Tétras for military use, and Niger has used it for insecticide spraying. Variants. "Data from" Jane's All the  World's Aircraft 2011/12