Notes
Presentation to the O’Hare Noise Compatibility Commission (ONCC) Technical Committee Meeting on April 14, 2020, prepared by the Chicago Department of Aviation (CDA). Covers the high-pitched whistling noise identified in the Airbus A320 family aircraft (A318, A319, A320, A321) manufactured before 2014, caused by Fuel Over Pressure Protector (FOPP) cavities — four cavities total, two per wing. Noise occurs during descent and diminishes after landing gear deployment. The proposed fix is a vortex generator installed in front of the FOPP vent opening, which reduces approach-phase noise by up to 4 decibels. Sources cited include Supercraft (2015) and Lufthansa Group (2014).