The US Federal Aviation Administration (FAA) has said it will add new terminology that will help pave the way for commercial air taxi operations by the middle of the decade. The agency proposed updating its definition of an air carrier, to add "powered takeoff" operations to regulations covering other commercial operations such as airlines, charter flights and air tours. “This vertical take-off definition rule lays the foundation that will allow operators to use this type of new aircraft,” the agency said in a statement sent to Reuters. The FAA is separately developing a vertical takeoff operations rule to certify pilots and operational requirements to fly electric vertical takeoff and landing (eVTOL) aircraft. The agency hopes to publish the proposal next summer. Billy Nolen, the FAA's acting administrator, said the agency doesn't expect the first eVTOL to begin commercial operation until late 2024 or, more likely, early 2025. "In any case, it will not happen until the security part has been satisfied," he said. Airlines and other operators are looking to develop transport services that use battery-powered aircraft that can take off and land vertically to transport travelers to airports or on short trips between cities, allowing them to avoid traffic. Earlier this month, the FAA issued airworthiness criteria that air taxi startup Joby Aviation will need to meet in order for its model JAS4-1 eVTOL aircraft to be certified. Joby recently said he expects to begin commercial passenger air taxi services in 2025, after receiving FAA approvals. The FAA expects to issue an implementation plan next May that will help it meet ambitious industry growth plans.