The U.S. civil and military aviation community has historically relied upon energy-dense liquid jet fuel that is derived from petroleum, which is subject to volatile pricing and uncertain supply and harmful to the environment. More recently developed jet fuel alternatives derived from nonpetroleum feedstock can help address those issues and other U.S. energy-related challenges, making development of alternative energy fuels (AJFs) of increased interest in the realm of aviation. Effective Federal research and development can enable AJF development by reducing the costs of producing fuel, facilitating effective evaluation and approval of promising fuel pathways, ensuring that environmental and social benefits accrue from the use of these fuels, reducing technical uncertainty, and promoting private sector investment in production.