After two years in conception and design, the prototype of this new light aircraft (VH-JSA) flew for the first time on 25 January 1989. The original 86.5 kW (116 hp) Textron Lycoming O-235 engine was later replaced by the O-320-D1A or IO-320-D1G.
A pre-production Mamba first flew in December 1989. Certification to Australian ANO 101-22/FAR 23 was nearing completion in the third quarter of 1990 and series production has started. Early orders include one from a local flying school, for aerobatic training, and three for the Conservation and Land Management Department of Western Australia. The latter are to be used for forest fire patrol. The Mamba was also being evaluated in late 1990 by the Royal Thai Army as a possible L-19 Bird Dog replacement.
The following details apply to the pre-production aircraft:

TYPE: Two-seat light aircraft.

WINGS: High-wing monoplane, with single bracing strut each side. NACA 4412 constant section; 1° 30' dihedral from roots. Two tubular metal spars with aluminium alloy skin. Trailing-edges have split flaps and Frise type differentially operating ailerons, latter each fitted with servo tab.

FUSELAGE: 4130 steel tube frame with aluminium alloy skins.

TAIL UNIT: Slightly sweptback vertical and non-swept horizontal surfaces. Variable incidence tailplane (on prototype only). Trim tab in one elevator.

LANDING GEAR: Non-retractable tricycle type. MAC cantilever self-sprung mainwheel legs, each with Cleveland wheel and Dunlop 6.00-4 x 4 tyre. Cleveland tailwheel has 5.00-5 x 4 Dunlop tyre and is steerable ±30°. MAC mainwheel brakes. Provision to fit Edo floats.

POWER PLANT: One 119 kW (160 hp) Textron Lycoming O-320-D1A or IO-320-D1G flat four engine with Hartzell or Hoffmann two-blade propeller. Fuel capacity 327 litres (86 US gallons; 72 Imp gallons). Oil capacity 9,1 litres (2,4 US gallons, 2 Imp gallons).

ACCOMMODATION: Extensively glazed cabin seating two persons in tandem. Door on starboard side. Space for 20 kg (44 lb) of baggage aft of seats. Cabin heated and ventilated.

SYSTEMS: 14V or 28V DC electrical system (50A alternator).

AVIONICS: Dual nav/com radios, glideslope, marker beacon receiver, ADF, PDR encoder and intercom.

ARMAMENT: External attachment under each outer wing (load limit 136 kg; 300 lb per station) for 3 in standard rockets or gun pods of up to 20 mm calibre.