Delta Air Lines is working to moderate noise pollution from its Airbus A321ceo twinjets through an innovative engine modification. The introduction of "tooth-like chevron structures" on the exhaust nozzles of these aircraft is designed to reduce engine noise. This modification is applicable to planes powered by CFM International CFM56 engines, as announced by the company in February 2002.
CFM International shared that the "new technology includes (...) a core chevron nozzle. (...) Flight tests on the Airbus A321 are scheduled for later this year, followed by certification and entry into service in early 2003." The goal was to enhance the aircraft's compliance with noise regulations by decreasing perceived noise levels.
This acoustic upgrade was partly a response to stricter noise regulations, specifically FAR Stage III and CAEP 5 recommendations. "Noise and emissions have become key factors in aircraft fleet planning and operations," explained CFM International. The adaptation ensures that the A321 model can operate within the acceptable noise limits.