Single-seat single-engined high-wing monoplane with conventional three-axis control. Wing has unswept leading edge, swept forward trailing edge and tapering chord; conventional tail. Pitch control by fully flying tail; yaw control by fully flying rudder; roll control by half-span ailerons; control inputs through stick for pitch/roll and pedals for yaw. Wing braced from below by struts; wing profile double-surface. Undercarriage has three wheels in tricycle formation; glass-fibre sus-pension. Push-right go-right nosewheel steer-ing connected to yaw control. Aluminium tube and sheet framework, with optional total-enclosure pod. Engine mounted at wing height driving tractor propeller. All aluminium and hardware is of aircraft quality.
The Zipper is a conventional three-axis machine with rudder pedals and centre stick, and it appears to be quite conventional in its choice of materials, being basically a tube-and-Dacron machine. There are some interesting features though, such as the tail boom, which is not tubular but is constructed of sheet aluminium alloy formed into a rectangular cross-section.
Most of the innovation, however, is centred on the wing design, which has an unusual shape plan, with ailerons attached to the trailing edges. The design allows the wing to be folded in two minutes, the maker claims, after which the aircraft can be towed on its own wheels, avoiding the expense of a trailer.
Engine is the direct-drive JPX PUL425, which is available in two states of tune - 22 hp standard or 26hp with tuned exhaust. The aircraft is sold in kit form, but Zenair says the kit takes only an afternoon to complete, having already been test-assembled in the factory before shipping. Other options include floats and wheel spats, while an enclosed cockpit, skis and propeller spinner are also offered.
Length overall 14.5 ft, 4.42 m
Height overall 5.5ft, 1.68m
Wing span 28.0ft, 8.53m
Mean chord 5.0ft, 1.52m
Sweepback 0 deg
Total wing area 140 sq.ft, 13.0 sq.m
Wing aspect ratio 5.6/1
Engine: JPX PUL425, 22hp at 4600rpm
Propeller diameter 42 inch, 1.07 m
Max static thrust 180 lb, 82 kg
Power per unit area 0.16hp/sq.ft, 1.7hp/sq.m
Fuel capacity 6.0 US gal, 5.0 Imp gal, 22.7 litre
Empty weight 180lb, 82kg
Max take-off weight 420 lb, 191 kg
Payload 240 lb, 109 kg
Max wing loading 3.00 lb/sq.ft, 14.7 kg/sq.m
Max power loading 19.1lb/hp, 8.7kg/hp
Load factors +6.0, -3.0 design
Max level speed 50 mph, 80 kph
Never exceed speed 80 mph, 129 kph
Cruising speed 40mph, 64 kph
Stalling speed 20 mph, 32 kph
Max climb rate at sea level 700 ft/min, 3.6 m/s
Take-off distance 120 ft, 35 m
Landing distance 80 ft, 25 m
Range at average cruising speed 100 mile, 161 km