In 2021, a United Airlines test flight using 100% sustainable aviation fuel took off from Houston, marking a significant step towards environmentally friendly flying. The U.S. government's ambitious 'Grand Challenge' aims to have sustainable fuels meeting all jet travel demand by 2050. High-profile investments in 2024 from airlines like American and Alaska Airlines, as well as startups like Twelve, are indicative of the industry's commitment to this goal. Various pathways to greener fuel are being explored, including hydrogen fuel cell engines, power-to-liquids technology, and biofuels. While these innovations show promise, challenges such as cost-effectiveness and scalability still need to be addressed. Companies like American Airlines are investing in hydrogen fuel cell engines, while others are focusing on eFuel production using power-to-liquids technology. Biofuels, derived from sources like municipal solid waste and agricultural plant waste, are currently the most viable alternative to traditional jet fuel. However, biofuels are still more expensive to produce, limiting their widespread adoption by airlines. Researchers and industry players, like Southwest Research Institute's Hsiang Yee Hoekstra, are working towards improving the sustainability and affordability of these green aviation technologies. While advancements have been made, including successful test flights and investments in innovative technologies, there is still a long way to go before sustainable aviation fuel becomes the norm in the industry. Collaboration between government initiatives, researchers, and airlines will be crucial in driving the progress towards greener and more environmentally friendly aviation practices in the future.