De Europese Unie heeft op 29 april 1999 een verordening van de Raad aangenomen, teneinde het geluid van motoren van subsonische vliegtuigen te beheersen en te verminderen.
On 29 April 1999, the European Union adopted a Council regulation with a view to controlling and reducing the noise produced by subsonic aircraft engines, limiting in due course the use of silencers, which do not resolve the problem completely, and helping airlines to update their fleets with new generation aircraft which create less pollution.