TYPE: Side-by-side ultralight kitbuilt.

PROGRAMME: Announced March 1996 in response to request for ultralight to meet Italian requirements; first flight of prototype (N12SX) with Jabiru 2200 engine, 28 February 1998. Five prototypes. First customer-built aircraft flown 12 June 2001.

CURRENT VERSIONS: Sonex: Kitbuilt, as described.
Waiex: Y-tailed derivative (name indicates Y-tailed experimental). Prototype (N12YX) first flown 19 July 2003 and made public debut at AirVenture 2003 following week. Data as per Sonex, except length 5.51 m (18 ft 1 in), empty weight 283 kg (625 lb), never-exceed speed 166 kt (309 km/h; 192 mph), stalling speed, flaps down 37 kt (68 km/h; 42 mph).
Xenos: Motor glider, based around Sonex front fuselage; described separately.

CUSTOMERS: Over 500 sets of plans and kits sold and 50 flying by August 2003.

COSTS: Sonex Airframe kit US$11,985 tailwheel, US$12,265 tricycle both excluding engine and wheels and brakes; plans US$600 (including two-day workshop) (2002). Waiex estimated completed cost US$25,000 (2003).

DESIGN FEATURES: Simple to assemble; 198 parts to easy-build kit. Wings removable for transport and storage. Quoted build time 700 hours.
NACA 64-415 aerofoil.

FLYING CONTROLS: Conventional and manual. Flaps.

STRUCTURE: Of 6061-T6 aluminium throughout.

LANDING GEAR: Choice of tailwheel or tricycle; both fixed. Titanium mainwheel legs and glass fibre speed fairings. Azusa wheels and brakes. Mainwheels 5.00x5, tailwheel (where fitted) 4x1 in.

POWER PLANT: Choice of power plants between 59.7 and 89.5 kW (80 and 120 hp), including Volkswagen 2180 and Jabiru 2200 and 3300. Two-blade, wooden, fixed-pitch Sensenich or Sterba propeller. Fuel capacity 61 litres (16.0 US gallons; 13.3 Imp gallons) in single fuel tank.