The main purpose of the Supersonic Aviation Modernization Act is to allow civil supersonic flights to operate in U.S. airspace under specific conditions. This legislation aims to modernize regulations surrounding supersonic travel, which has been largely restricted due to concerns about noise pollution, particularly sonic booms. Key provisions of the Act include the requirement for the Federal Aviation Administration (FAA) to develop and revise regulations that will enable civil aircraft to fly faster than the speed of sound, provided that they do not create sonic booms that reach the ground.