The  Federal Aviation Administration (FAA) , under  FAR Part 36 , governs the certification of aircraft as it relates to noise levels. Depending on the type of aircraft, FAR Part 36 determines the maximum allowable noise level. The FAA also follows the model of the International Civil Aviation Organization (ICAO) which sets global aircraft noise standards known as  Stages . Currently, the FAA mandates that all aircraft that fly within the United States comply with  Stage 3  requirements and all new aircraft comply with Stage 5 requirements which are 17 decibels less than Stage 3.