Developments in magnets and rechargeable batteries have pushed transportation electrification to a higher pace over the last couple of years. In the past one-decade enormous interest has been seen in the eVTOL aircraft market, from tiny toy drones to scaled-up personal eVTOL aircraft. Many companies are showcasing the prototypes of private electric aeroplanes and flying taxis. However, at this stage, it is also essential to keep carbon emission and efficiency of the electric machine as a weighted objective to achieve sustainable development. This paper presents a model for calculating the carbon emission and efficiency of the slotted and slotless machine used for the eVTOL Application, compares the results, and discusses the trade-off analysis for both machines. Moreover, it further identifies and suggests ways to achieve sustainability.