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I have noticed that the A220 makes a very roaring noise when the engines spool up from idle. Definitely distinctive compared to other aircraft. In fact, it gets to the point where I can hear this noise for 5 km outside the airport as the only regular sound. If I can hear it, surely others can hear it too, which leads me to wonder how this distinctive sound is created and whether efforts are being made to reduce its volume.

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  • $\begingroup$ The A220 uses essentially the same geared turbofan engine as the A320neo, do any of those fly into the same airport for comparison? According to Wikipedia the A320neo uses the PW1100G, 20 blades, fan diameter 81 in (206 cm). The A220 uses the PW1500G, 18 blades, fan diameter73 in (185 cm), and lower thrust. $\endgroup$ Dec 23, 2023 at 15:58
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    $\begingroup$ Yes, I live near Hamburg Airport, to which many A320 (Neo), 737 and other similar fly. None of them compares to this sound. Every time I hear the sound, it's an A220 according to FR24. $\endgroup$
    – Meyssam
    Dec 23, 2023 at 16:10
  • $\begingroup$ Maybe it's thrust reverser or gear vortex shedding? Especially vortex shedding would explain the difference between A220 and A320, as they have less in common aerodynamically than engine wise. aviation.stackexchange.com/questions/93373/… $\endgroup$
    – Agent_L
    Jan 1 at 15:15

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The A220 is powered by Pratt & Whitney PW1500G engines.

According to Pratt and Whitney, the noise is a "low-power transient combustor tone caused by pressure changes against the combustion structure."

The resulting effect and sound is similar to blowing over the opening of a bottle.

P&W do say it is more noticeable because the PW1500G is relatively quiet otherwise.

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  • $\begingroup$ Thanks for the information. I can confirm the sound, but I cannot agree with P&W's statement. This sound is definitely much louder than most other aircraft flying to Hamburg. The volume compares to the 777's startup sound. $\endgroup$
    – Meyssam
    Dec 23, 2023 at 16:13
  • $\begingroup$ yeah - I agree. The ones I heard certainly seemed louder (to me) than many of the other aircraft engines. $\endgroup$
    – Rory Alsop
    Dec 23, 2023 at 16:14
  • $\begingroup$ That second sentence is copied from my answer to a question that asked the same thing, is this a duplicate? $\endgroup$ Dec 23, 2023 at 16:27
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    $\begingroup$ @AadirajAnil - I've not seen your answer. I found that, and similar wording on a couple of aviation sites. Can you pop up a link? $\endgroup$
    – Rory Alsop
    Dec 23, 2023 at 16:50
  • $\begingroup$ It's almost a turboprop with a fixed pitch propeller with lots of blades. The core engine is quite small compared to most turbofans and is putting a lot of air through at high velocity, so the sound out the exhaust tailpipe is loud. $\endgroup$
    – John K
    Dec 23, 2023 at 19:05
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The sound you are hearing might be due to the variable bleed vanes as well as the variable stator vanes that help direct airflow and change position depending on the power setting. It is also found on other engines that have a similar TALON combustor to the PW1500G like the PW800. It is likely due to the sound harmonics of the engine as well.

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    $\begingroup$ Is this a statement of an answer to the question, or is it a guess? If the former, please provide a reference for what's being presented as factual. If the latter... please don't post guesses as answers. $\endgroup$
    – Ralph J
    Jan 2 at 1:31

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