...are based on the Chapter 4 standards adopted by ICAO in 2001. The Stage 4 standards are 10 decibels "ICAO is an advisory organization affiliated with...standards and recommended practices and procedures. FAA is the US representative to ICAO. 'Some older business class jets that do not meet Stage 3 standards...

...International Civil Aviation Organization (ICAO), an advisory organization affiliated with the United Nations, aims to promote the establishment of international...standards and recommended practices and procedures. As such, ICAO has issued policies and guidance on assigning costs and the establishment of charges...