Aircraft Noise

The aircraft types in 

 are certified against noise standards that are referred to as Chapters 3, 4 and 14,¹ which became applicable from 1977, 2006 and 2018, respectively. The International Civil Aviation Organisation (ICAO) is currently reviewing the noise limits for these aircraft categories with the aim to create a new chapter that would become applicable in the next five years.

The ICAO also sets noise standards for light propeller- driven aircraft (Chapter 10) and helicopters (Chapters 8 and 11), whose noise limits were last updated in 1999 and 2002 respectively. Discussions have been initiated within the ICAO Committee on Aviation Environmental Protection (CAEP) noise technical working group to consider an update of these standards.

 illustrates the differences on an operational basis between the successive noise certification standards for each aircraft category in  . The circles represent the landing and take-off 80 dB noise footprint area for virtual aircraft that would just meet the limits of the Annex 16 Volume I Chapters and for an aircraft that represents the current state-of-the-art in its category.

Historic developments in certified aircraft noise levels are illustrated in 

 The figure represents the cumulative margin² to the Chapter 3 limits for the heaviest weight variants and maximum thrust rating of aircraft types certified since 1990  . The new data since the last report (e.g. Falcon 6X, Gulfstream GVIII-2, ATR 42/72 modified engine, A321 XLR) highlights the continued marginal improvements in noise levels since the 2010s. Jet aircraft continue to show cumulative margins of 8 to 15 EPNdB compared to the Chapter 14 limit. Margins for turboprops are lower, illustrating the slower development of noise reduction technology in this category. Overall,   confirms that technology is available across all categories to support an increase in noise stringency in the short term.

In 2019, an Independent Experts Panel established by the ICAO CAEP agreed on medium-term (2027) and long-term (2037) noise goals for leading edge technology 

 These goals were set for each aircraft category (except turboprops) and are also represented in  . As the medium-term goal of 2027 approaches, there is an opportunity to review whether this has been met and to update the goals with later target years for them to remain relevant.

While 

 contains certified noise levels of specific aircraft type designs provides insight on the noise performance of the in-service European fleet registered in EU+EFTA at the start of 2024. The figure shows the trend over time of the average noise margin to the Chapter 3 limit for all aircraft built in a given year by aircraft category.

The average aircraft noise margins of regional, single- aisle and twin-aisle jets have flattened out over recent years. This suggests that new deliveries in these categories now consist entirely of aircraft types certified in the 2010s (e.g. Embraer ERJ E2, Airbus A320neo, A330neo, A350, Boeing 737Max, 787), which have a better noise performance than their predecessors. The average noise performance of the in-service fleet will continue to improve in the near to medium term as the older and noisier types still operating in Europe are gradually replaced. The rate of improvement will depend on the rate of new deliveries, which has been negatively affected by the COVID crisis and recent challenges in the supply chain to meet demand.

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¹ These are chapters of ICAO Annex 16 Volume I, which contain international aircraft noise standards.
² ‘Cumulative margin’ is the sum of the individual margins (difference between certified noise level and noise limit) at each of the three Chapter 3 noise measurement points, expressed in Effective Perceived Noise deciBels (EPNdB).