This thesis describes some of the processes and results obtained during the design and prototyping of a single seat experimental aircraft. The major aim was to maximise the Triaviation score of the aircraft. This score is a combination of the top speed, the stall speed and the rate of climb. The aircraft has been designed constructed, inspected and flown. The process of designing and prototyping is outlined in this thesis. Details are provided regarding preliminary design, numerical optimisation and the process of building the prototype. The aircraft registered VH-ZYY is a shoulder wing monoplane using a Continental IO-240 aircraft engine. The aircraft has a high power to weight ratio and light wing loading to assist it to climb well and fly slowly. Full span flaperons are used to increase the maximum coefficient of lift at the stall. The primary structure is aluminium with a carbon fibre and nomex cored cowl. All steel components have been formed with 4130 chrome molybdenum aircraft grade tubing. All hardware uses AN specification parts. VH-ZYY is registered in Australia as an Experimental aircraft.