As the commercial aviation industry increasingly embraces “green” issues including, for example, SAF, it is useful to consider another feature that is much more noticeable to people – noise. So which is the quietest aircraft?
The latest generation of aircraft, from the MAX and various neos to the smaller E2 and A220s, all utilize the newest and quietest engines. We highlight these aircraft as they are the most utilized and almost certainly fly over readers daily. In other words, these are the aircraft you would notice. How would you notice them? By how much quieter they are than the previous generation. In other words, the aircraft you hear these days is most likely to be a previous generation rather than the latest versions.
To provide readers an immersive experience, we recommend watching some videos. While it’s true that aircraft weight varies and therefore engine noise also varies. These examples are a guide and not scientific comparisons.
- Previous Generation – Here we have three A330s with each of the three engine types at takeoff.
- Current Generation – A330neo
Next, let’s take a look and listen to an A320ceo vs an A320neo. The differences should be clear – the newer engines are significantly quieter. The newer engines have a smaller noise “footprint” – the newer engine noise dies away much faster. Next look and listen to the 737NG vs the 737 MAX. Also a major improvement.
In the next example, the video shows various aircraft – some with new engines and some with older engines. Of particular interest is comparing the A220 and E2-190 as they have virtually the same engine (P&W GTF).
These last two are among the quietest aircraft in service. The E2-195 has an MTOW of 62,000Kg compared to the A220—300 at 67,600Kg and this is an important difference. A heavier aircraft can be expected to be noisier. Yet being able to tell the difference in aircraft without looking is probably impossible.
In the last video, we have a factory E2-190 (likely very light load) and a commercial flight A220-100 which are smaller models in their families. Despite the non-scientific aspect of these videos, the actual noise difference is probably imperceptible to somebody within earshot. For example, the A220 has a 50% smaller noise footprint than previous generation aircraft and the measured noise difference is 18 EPNdB (the cumulative margin vs the ICAO Chapter 4 certification standard) – a large enough difference you can hear.
The Journal of Exposure Science and Environmental Epidemiology published a study in 2018 titled “Assessment of noise in the airplane cabin environment”. The study reports that decibel levels do not differ significantly. The 737 is the loudest aircraft at 4.9 decibels higher than the average of Embraer regional jets (E-135; E-145; E-170; E-175 and E-190). Since noise measurement uses a logarithmic scale, the noise differential between the “louder” 737 and Embraer regional jets is about 50%. As mentioned above, a heavier aircraft can be expected to make more noise. Clearly, the 737 is larger than a regional jet. The study also found that the 737 is 0.9 decibels “louder” than the comparable A320, which means about 10% “louder”.
The quietest commercial aircraft in service today are likely the Airbus A220 and Embraer E2. These would be followed by the A320neo and 737MAX. While you might be able to tell the noise level difference between these two groups, it is unlikely you could tell the difference within the group without looking.