Humbert Tétras

Tétras
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Role	Two seat ultralight or kit build
National origin	France
Manufacturer	Humbert Aviation
First flight	c.1992
Introduction	1994
Status	in production
Number built	c.150 by 2010
Unit cost	kit with Rotax 912 UL engine €15,000; flyaway €31,500 (2001)

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 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

Tétras A

Initial version

Tétras B

Standard version, introduced 1998. Early examples had the HW 2000 engine but the 80 hp (60 kW) Rotax 912UL, or optionally the 100 hp (75 kW) Rotax 912ULS engine, is currently (2011) fitted. Currently available.

Tétras BS

912 ULS engine. Currently available.

Tétras CS

Introduced 2007 with a 600 mm (23.6 in) shorter span wing. 912 ULS engine. Marketed 2008-9.

Tétras CT

Tricycle undercarriage version of CS, with 512 UL engine. Marketed 2008-9.

Tétras CTS

As CT with 512 ULS engine. Marketed 2008-9.

Operators

Burkina Faso

• Military of Burkina Faso – Three aircraft were donated by France in October 2012.

Specifications (Tétras B)

Data from Jane's All the World's Aircraft 2011/12

General characteristics

• Capacity: 2
• Length: 6.50 m (21 ft 4 in)
• Wingspan: 10.10 m (33 ft 2 in)
• Height: 2.06 m (6 ft 9 in)
• Wing area: 15.70 m² (169.0 sq ft)
• Airfoil: NACA 23012
• Empty weight: 256 kg (564 lb)
• Max takeoff weight: 450 kg (992 lb) ; where permitted, 495 kg (1,091 lb)
• Fuel capacity: 60 L (15.9 USgal, 13.2 Impgal) standard. Can be increased to 85 L (22.5 USgal, 18.7 Impgal) outside France.
• Powerplant: 1 × Rotax 912 UL flat four, 59.6 kW (79.9 hp)
• Propellers: 2-bladed DUC FC composite, 1.75 m (5 ft 9 in) diameter

Performance

• Maximum speed: 194 km/h (121 mph; 105 kn)
• Cruising speed: 180 km/h (112 mph; 97 kn) at 75% power and 3,048 m (10,000 ft)
• Stall speed: 55 km/h (34 mph; 30 kn) flaps down
• Range: 700 km (435 mi; 378 nmi) with standard fuel capacity
• g limits: +4/-2
• Rate of climb: 7.5 m/s (1,480 ft/min) maximum at sea level

See also

Aircraft of comparable role, configuration and era

• Blue Yonder Merlin

External links

• Official Humbert website