Reducing the emissions of ultra-fine particles in the vicinity of airports to minimise detrimental health effects for near-airport residents and airport personnel has been the main objective of the project. This report details the realisation of this goal which was done by designing a hybrid aircraft with notable improvements in the efficiency and emission characteristics. The aircraft in question is named the ’Low Emission Alternative Fuel’ aircraft, or ’LEAF’. Design of essential components and systems is presented along with evaluation of aspects needed for LEAF aircraft to enter the market by 2035.