Claude Noin designed the Choucas, a side-by-side touring motorglider of tailless configuration, using the same materials as the Sirius. The Choucas (French for “jackdaw”) is a two-place side-by-side (may be flown from either seat) touring motorglider (ULM under French regulations) with front-mounted engine.
Designed as a light, economical and safe touring motorglider, the Choucas is available for amateur construction. It is commercialized as a partial kit for homebuilders, including all the molded composite components. This motorglider has a fast-build fuselage kit.
The Choucas design was initiated in 1994 and the prototype flew for the first time at the end of 1996. The Choucas accumulated over 500 hours of testing in a flight school environment. It has proven itself as an incredibly versatile and easy-to-fly aircraft.
ALPAERO, pre-manufacture Choucas sub-assemblies the facilities at Gap-Tallard, the most difficult parts, requiring the use of composite materials, large molds, special tools or skills, are all pre-manufactured. The wings can be built easily with traditional wood and fabric techniques, and all other fabrications can be accomplished by average builders.
Flying controls: flying wing formula, pitch control by elevators in inboard wing trailing-edge, ailerons outboard, large rudder. Trim tabs on elevators, DSF spoilers/airbrakes on upper surface wing.
Structure: standard fuselage molded in half-shells of carbon fibre/epoxy (with glass fibre/epoxy fuselage available at lower cost with weight penalty), composites wing structure with wooden main spar and glass fibre/epoxy stiffened Styrofoam ribs. The wing uses a modified Abrial/St Cyr airfoil, with 17 % thickness, it can be detached in two parts weighing 55 kg each (on the prototype). Leading edge made of hot wire cut foam laminated with glass fibre and epoxy resin, as an alternative the leading edges can be built as a birch plywood D-section, or molded in carbon fibre. Wing covered with heat-shrink Dacron. Lexan/polycarbonate canopy with carbon fibre frame.
Landing gear: The landing gear is a one-piece composite part, and can be used as a step to access the cockpit.
tailwheel type, fixed. Streamlined fairings on main legs and wheels. Drum brakes.

Engine: One 37.3 kW (50 hp) Rotax 503
Reduction: 2.58:1 gear
Propeller: two-blade carbon fibre, Folding forward optional
Propeller diameter: 1.60 m (5.3 ft)
Wing span: 14.35 m (47.1 ft), optional extension to 15 m
Length overall: 5.35 m (17.6 ft)
Height overall: 1.95 m (6.4 ft)
Wing area: 21.30 sq.m (229.3 sq ft)
Aspect ratio: 9.44:1
Airfoil: modified Abrial/St Cyr 17% airfoil
Fuel capacity: 36 litres (9.5 US gallons, 7.9 Imp gallons) in fuselage tanks
Usable fuel: 35 litres (9.25 US gallons, 7.7 Imp gallons)
Optional fuel: wing tanks (2 x 35 litres) in the Carbon version
Weight empty:
FAI ultralight version : 265 kg (573 lb)
experimental version : 290 kg (639 lb)
Max T-O weight:
FAI ultralight version : 450 kg (992 lb)
experimental version : 510 kg (1124 lb)
Max wing loading :
FAI ultralight version : 21.12 kg/sq.m (4.33 lb/sq ft)
experimental version : 23.94 kg/sq.m (4.90 lb/sq ft)
Cruising speed at 75% power: 130 km/h (70 kt, 81 mph)
Max speed: 180 km/h (97 kt, 112 mph)
Stalling speed: 60 km/h (33 kt, 38 mph)
VNE: 97 kt / 112 mph / 180 kmh
Max rate of climb: 180 m/mn (590 ft/mn)
T-O run: 100 m (328 ft)
Take-off distance (50ft obstacle): 660 ft / 200 m
Landing distance (50ft obstacle): 820 ft / 250 m
Landing run: 150 m (492 ft)
Best glide ratio: with a fixed propeller: 26:1
with a folding propeller: 24:1 (14.35 m version)
26:1 (15 m version + winglets)
Min rate of sink: less than 1.00 m/s (3.28 ft/s) at 80 km/h with a fixed propeller
G limits: + 8 / -4 G

Noin Aeronautiques Choucas
Engine: Rotax 503, 50 hp
Wing span: 14.35 m
Wing area: 21.80 sq.m
MAUW: 450 kg
Empty weight: 260 kg
Fuel capacity: 38 lt
Max speed: 170 kph
Cruise speed: 130 kph
Minimum speed: 60 kph
Climb rate: 4 m/s
Seats: 2
Fuel consumption: 12 lt/hr
Kit price (1998): 55 000 Fttc