Who has the authority to regulate the use of navigable airspace in the United States?

The authority to regulate the use of navigable airspace in the United States lies with the FAA Administrator. This is primarily because the Federal Aviation Administration (FAA) is the governmental body tasked with overseeing and regulating all aspects of civil aviation, including the management of airspace. The FAA establishes the rules and regulations that govern the operation of aircraft within this airspace, ensuring the safety and efficiency of both commercial and private aviation.

The FAA's jurisdiction includes creating air traffic control procedures, establishing airspace classes, and setting rules for pilots and aircraft operations, all of which directly pertain to the navigable airspace. Therefore, the regulations and policies crafted by the FAA Administrator are crucial for maintaining safe and efficient air travel throughout the United States.