The Sunbird has a great payload due to its lightweight composite construction (see below). The design MAUW is currently 250kg.
It has a 25 litre nosetank together with two 14 litre wing tanks. There is under-seat stowage amounting to 20 litres volume /10kg in weight.
The controls are all pushrod with the exception of the rudder, and the nosewheel is also steerable.
Wing Span: 6.4m. Wing Area: 7.75sqm Length: 4.75m. Cockpit Width: 0.62m. Empty weight (excluding engine): under 90kg! Weight with Aixro XF40 engine, 116kg (payload 134 kg). Weight with Hirth F23, around 122kg (payload 128kg).
Design Stress:- +4g/-2g Limit loads (+6g/-3g Ultimate)
Stall Speed (flaps):- under 35 knots. Climb rate (35hp): 600 to 1000 fpm @ MAUW, depending on propellor. Great slow speed handling with its benign wing, and excellent short runway handling characteristics.
Recommended approach speed: 42 to 50 knots with full flaps. Flap limiting speed 68 knots
Minimum takeoff speed: 44 knots, with 15 degree flaps.
Cruise Speed (35hp):- 100 mph. Max Speed (35hp): 115 mph. (Depends on chosen prop)
Speed in Gusts: 91mph. Design Vne: 129mph (To be confirmed)
Potential Endurance /Range (4 Stroke): Up to 7 hours / 700 miles.
Potential engines and props (25kg to 45kg approx): -
Note: Prop sizes up to 60 inch. Props for Aixro: E-mail us.
4 Strokes:- Aixro XF40 rotary (our preferred standard engine). This engine, which is installed in the prototype, is water cooled. We have fitted two radiators either side of the engine (optional small cockpit radiator as extra). The engine comes with a 2.5 to 1 belt reduction unit as standard and develops 35hp at 6500prm (limited to max 7000rpm). There is an option for a 3.0 to 1 belt drive. Lubrication is by 2 stoke oil mix in unleaded fuel at 50 to 1. Fuel burn is expected at 6 to 8 litres/ hour.
Other possibles; Hirth F23, Briggs 4 stroke variants and various others.
We are looking at potential electric engines. The narrow nose would suit future electric powered versions. We continue to wait on product development.