Sunbird Mk2 Design Specifications
The new (Mk2) Sunbird has been significantly upgraded since first launched in 2015.
The current design MTOW is now impressively 300kg. The anticipated empty weight, without engine and prop, is about 102 kg. Whichever engine you wish to install, the payload will be amazing, thanks to its lightweight yet strong composite construction. Maximum pilot weight remains at 105kg for the time being. Minimum is still 55kg excluding tail ballast. Rudder pedal to seat-back is about 110cm.
The latest model will now have 2 composite wing tanks, each around 25 litres (to be confirmed).
There is a new behind-the-seat baggage bay with a weight allowance of up to 15 kg and over 3 cubic foot capacity - useful for, say, a small tent and holdall, etc. There is also a small amount of under-seat stowage for small items.
The controls are all pushrod with the exception of the rudder (cables), with steerable nose wheel (push right = turn right). The main wheels and braking system are Black Max, very light but powerful.
Wing Span: 6.8m. Wing Area: 8.35 sqm, Length: 4.75m. Cockpit Width: 0.62m.
Design Stress:- +4g/-2g Limit loads (+6g/-3g Ultimate)
Design Vne: 117 knots. Dive speed Vd: 130 knots (provisional). Speed in gusts: 85 knots.
Stall Speed (flaps):- under 34 knots with flaperon mixer.
Cruise Speed :- Depends on engine and prop. Expect 70-80 knots at 40HP, 80-95 knots at 50HP Higher cruise speeds can be obtained at the expense of initial thrust with slightly smaller props. The maximum recommended cruise speed is 100 knots (as recommended for microlights generally)
Endurance : 2 to 4 hours for 2 strokes, depending on engine etc.
Potential engines and props (35kg to max 50kg, 40 HP to 55 HP recommended ): -
4 Strokes:- V-Twins such as B&S Vanguard: Tuned versions 40 HP -50 HP possible
2 Strokes:- The Hirth F23 Boxer, various Rotax engines (eg models 447, 462, 503. Possibly 532, 582).
The 532 and 582 will fit inverted, but are not yet endorsed as they could prove to be too powerful. Careful choice of prop sizes may be required. They are however possible options.
For all listed engines so far, the maximum prop diameter is 56 to 58 inch, depending on the engine due to varying prop hub positions. It may be necessary to fit a 3-blade prop. in some cases.