View Full Version : Zenair zipper

10-09-13, 22:39 PM
Now this looks like low and slow fun. Does anyone know about this at all as if the new rules go ahead I think I am going to go 3 axis. I am we'll aware of the fact that this is far from a touring machine but for an evenings bimble then folding the wing up to pack it away it looks just right. Are there plans available as it is a very simple design?

15-02-14, 21:58 PM
1100911010[QUOTE=dompech;89990]Now this looks like low and slow fun.

*If it will fly on 23hp, it can use a completely stock Briggs Vanguard, no tuning or alteration required at all. With merely removal of the governor to save weight and allow the motor to access the higher rev ranges, still completely safe at 4200-4500, it will push out a little more. With mild tweaks at low cost it will go to 30hp and maybe allow trimming of that wingspan and a little more touring speed.

The reduction drive on mine will bolt on 'prop high' or 'prop low' just like the Rotax boxes do; this means thrust line is aligned with the base mounts so no top braces necessary-saving weight.

In tractor form the engine will cool adequately from prop wash, as exhaust is forward, only pushers need the cowl and fan, saving weight and adding power.

If I went fixed wing this would be a good simple choice and give flexwing simplicity and experience, and never assume you cannot tour such a machine.

With full fancy exhaust and cowls, heavy starter and silencer mine went to just over 43 kilos, knock 3 off with free air cooled and normal starter using stock camshaft, 2 more using a shorter exhaust; anyone decide to do this I'm happy to assist and advise.

Good post


Paul Dewhurst
16-02-14, 19:19 PM
Not sure if any zippers made it into to UK? Certainly I have never seen one and doesn't seem to be an enduring type in the US as regards large numbers flying now. Vertical tail seems very small indeed, and pictures of them flying seem to show quite excessive washout, so performance may be quite limited.

for US ultralights that did make it here and that I have flown, I can recommend the Phantom - still probably the best handling solo three axis machine ever made. Quiksilvers are brilliant fun, but need low winds. The Swallow I can also recommend. Pterodcatlys sold in reasonable numbers here and are a real blast to fly. Goldwing has great performance and looks, a bit twitchy in pitch and dull in roll though. And if you have a big hangar, or lots of time to derig, the Eagle will bring a smile to your face!


16-02-14, 23:16 PM
See what you mean Paul

Went on Wikipedia and found this:-

Data from Kitplanes[2]

General characteristics
Crew: one
Length: 16 ft 8 in (5.08 m)
Wingspan: 28 ft 6 in (8.69 m)
Height: 8 ft 2 in (2.49 m)
Wing area: 142 sq ft (13.2 m2)
Empty weight: 250 lb (113 kg)
Gross weight: 510 lb (231 kg)
Fuel capacity: 5 US Gallons (19 litres)
Powerplant: 1 Rotax 447 twin-cylinder, single-ignition, two-stroke aircraft engine, 40 hp (30 kW)

Maximum speed: 61 mph (98 km/h; 53 kn)
Cruise speed: 55 mph (48 kn; 89 km/h)
Stall speed: 26 mph (23 kn; 42 km/h)
G limits: +9/-6.6 (ultimate), +6.6/-4.4 g (operational)
Rate of climb: 800 ft/min (4.1 m/s)
Wing loading: 3.59 lb/sq ft (17.5 kg/m2)

Could have been written around the SSDR rules eh?



PS designed as aerobatic but could not be advertised because of liability ;-)