Stakeholders in the aviation industry committed to a goal of 50% reduction in carbon emissions by the year 2050, to be achieved by reducing emissions 1.5% each year from 2020 onwards. There are multiple pathways to achieve this goal however; with, the most promising technology being Sustainable Aviation Fuels (SAF), which are biofuels blended with kerosene. As the industry shifts towards SAF, it is important to evaluate these fuels in terms of their long-term sustainability, and this is the objective of the current study. Sixteen types of fuels were assessed which include fossil, natural gas, electric, and SAF. A Multi Criterion Decision Making methodology was adopted which considers three categories, namely environmental, economic, and social aspects which in turn are broken up into 8 indicators in all (such as ecological footprints, cost of transportation, investment cost, operating costs, employment generation, and health & safety). A Monte Carlo analysis was also performed to analyze sensitivity of the results to the weights attributed to the three categories. The most sustainable fuel was found to be Hydrogen, with a score of 0.91 out of 1.0. The least sustainable were determined to be the military kerosene-based fuels (with the experimental fuel JP-8 + 100LT being the poorest with a normalized score of 0.50).