The Wombat, which is available in two basic versions comes with a tricycle undercarriage, but in its Bunyip form is a tail dragger aircraft. Construction is Dacron covered aluminium structure. Development work is continuing and a powerplant change to the English Huntington Field engine is currently being planned.

Bunyip
Engine: Fuji Robin 440
Prop: 144cm x 96cm pitch
Wingspan: 8.41 m
Length: 4.7m
Weight: 150kg
Fuel capacity: 23 ltr
Econ cruise speed: 50 kts
Stall: 27kts

In 1983 ULAC is working on a MX PUL 425 engined single seater of the X-99, called the X 77, but no other details were available.

Tandem two seat single engined high wing monoplane with conventional three axis con¬trol. Wing has unswept leading and trailing edges, and constant chord; V tail. Pitch/yaw control by elevon; roll control by one third-span spoilers; control inputs through stick for pitch/roll and pedals for yaw. Wing braced from above by kingpost and cables, from below by cables; wing profile 100% double surface. Undercarriage has three wheels in tail dragger formation; steel spring suspension on tailwheel and suspension on main wheels. Push right go right tailwheel steering connected to yaw control. Brakes on main wheels. Aluminium tube framework, with optional pod. Engine mounted below wing driving pusher propeller.

Georges Borgeaud, the president of ULAC, acquired on the 14 August 1981 the rights to sell in Europe and Africa the Maxair Hummer. Starting with the basic single seater model designed by the late Klaus Hill, ULAC has developed its own tandem two seater, the X 99. The transformation principally in¬volved raising and reinforcing the wing, increasing the track of the undercarriage, the addition of spoilers to change the machine into a conventional three axis control aircraft and finally the adoption of the Hirth motor.

The prototype made its first flights at the beginning of 1982 above the Californian desert near to Salton Sea. For the distribution of this aircraft, George Borgeaud built a factory at Monthey in the Vallais area in Switzerland. Shown at the first European Salon of Microlights at Lyon Bron in Septem¬ber 1982, and later at the microlight assembly at Blois in France, this machine met with considerable success amongst the established pilots at whom it is aimed. Georges has consistently followed an intelligent sales policy, hinged on safety, and will only sell this aircraft in Europe to qualified private pilot’s licence holders.

Ready to fly X 99s cost US$8650 in 1983 ex works for the standard version, trailer included. Standard are compass, ASI, altimeter, rev counter and CHTG. As an option, it can have climb, turn and slip gauges. Its spoilers can be used together as air brakes and the machine can be flown solo (from the front seat) without any modification. The rear seat can be replaced by a large supplementary fuel tank and other options include skis, floats, pod, main wheel fairings, dual controls, a second instrument panel for the rear seat and a three blade propeller.

Georges was working on a new wing design which can be rigged in two different spans 32.8 ft or 45.9 ft (10.00 or 14.00 m), and the larger span would bring the X 99 comfortably within British ultralight law.

Length overall 17.1 ft, 5.75 m]
Height overall 8.8 ft, 2.65 m
Wing span 34.1 ft, 10.40 m
Constant chord 4.4ft, 1.32 m
Sweepback 0 deg
Tailplane span 8.2 ft, 2.50 m
Fin height 2.1ft, 0.90m
Total wing area 147 sq.ft, 13.7 sq.m
Total spoiler area 1.9 sq.ft, 0.18 sq.m
Tailplane area 19.4 sq.ft, 1.8 sq.m
Total elevon area 13.6 sq.ft, 1.3 sq.m
Wing aspect ratio 7.9/1
Wheel track 4.1 ft, 1.24 m
Wheelbase 7.5 ft, 2.25 m
Tailwheel diameter overall 10 inch, 26 cm
Main wheels diameter overall 14 inch, 35 cm
Floats, dimensions 10. 1 x 2.0 ft, 3.30 x 0.59 m
Skis, dimensions 2.1 x 0.6 ft, 0.87 x 0.14 m
Engine: Hirth 272R 438 cc, 40 hp at 7000 rpm
Prop¬eller diameter and pitch 54 x 30 inch, 1.37×0.76m
Toothed belt reduction, ratio 2.2/1
Max static thrust 252 lb, 114 kg
Power per unit area 0.27 hp/sq.ft, 2.9 hp/sq.m
Fuel capacity 3.2 US gal, 2.7 Imp gal, 12.0 litre in main tank
Fuel capacity 21.7 US gal, 18.1 Imp gal, 82.0 litre in reserve
Empty weight 320 lb, 145kg
Max take off weight 662 lb, 300kg
Payload 3421b, 155 kg
Max wing loading 4.501b/sq.ft, 21.9kg/sq.m
Max power loading 16.6 lb/hp, 7.5kg/hp
Load factors; +5.0, 3.0 ultimate
Max level speed 62 mph, 100 kph
Never exceed speed 71 mph, 115 kph
Max cruising speed 53 mph, 85 kph
Economic cruising speed 44 mph, 70 kph
Stalling speed 24 mph, 38 kph
Max climb rate at sea level 350 ft/min, 1.8 m/s
Min sink rate 680 ft/min at 28 mph, 3.5 m/s at 45 kph
Best glide ratio with power off 7/1 at 37 mph, 60 kph
Take off distance 180 ft, 55 m
Land¬ing distance 80ft, 24m
Service ceiling 13,100ft, 4000 m
Range at average cruising speed 75 mile, 120 km

Single seat single engined high wing monoplane with conventional three axis control. Wing has unswept leading and trailing edges, and constant chord; cruciform tail. Pitch control by elevator on tail; yaw control by fin mounted 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 Ga 549; double surface. Undercarriage has three wheels in tricycle formation; steel spring suspension on nosewheel and glass fibre suspension on main wheels. Push right go right nosewheel steering connected to yaw control. Brakes on main wheels. Aluminium tube framework, with pod. Engine mounted below wing driving pusher propeller.

Two prototype examples of this machine were on show at Friedrichshafen in March 1983, but the Wildente did not fly for the first time until 16 April. This machine has a welded tubular framework, which appears to have great rigidity and is also claimed to allow derigging and rigging in less than 10 min. It is sold built and ready to fly. Options include wheel fairings and a three blade propeller.

Length overall 19.4ft, 5.90m
Wing span 34.4ft, 10.50m
Constant chord 4.9ft, 1.50 m
Total wing area 166 sq.ft, 15.4 sq.m
Wing aspect ratio 7.2/1
Wheel track 5.1 ft, 1.55 m
Engine: Hirth F263, 22hp at 4000rpm
Propeller diameter 51 inch, 1.30 m
Belt reduction, ratio 1.8/1
Max static thrust 172 lb, 78 kg
Power per unit area 0.13 hp/sq.ft, 1.4 hp/sq.m
Fuel capacity 5.3 US gal, 4.4 Imp gal, 20.0 litre
Empty weight 221 lb, 100kg
Max take off weight 464 lb, 210kg
Payload 243 lb, 110kg
Max wing loading 2.79 lb/sq.ft, 13.6kg/sq.m
Max power loading 21.1 lb/hp, 9.5kg/hp
Load factors; +6.0, 3.0 ultimate
Never exceed speed 62mph, 100kph
Economic cruising speed 47 mph, 75 kph
Stalling speed 26 mph, 42 kph
Max climb rate at sea level 240 ft/min, 1.2m/s
Min sink rate 310ft/min, 1.6m/s
Best glide ratio with power off 9.5/1
Take off distance 130 ft, 40 m
Range at average cruising speed 124 mile, 200 km