 Airspace class (United States)

The United States airspace system's classification scheme is intended to maximize pilot flexibility within acceptable levels of risk appropriate to the type of operation and traffic density within that class of airspace – in particular to provide separation and active control in areas of dense or high-speed flight operations.The Albert Roper (1919-10-13 The Paris Convention) implementation of International Civil Aviation Organization (ICAO) airspace classes defines classes A through G (with the exception of class F which is not used in the United States).