Took an international flight in mine and I have to say they reduce engine noise quite well. Not on the same level as the WH-1000XM3 - which I also had on me for the trip - but you can't really compare the sound or ANC of these to headphones or wired counterparts really. 2nd week in, really enjoying mine, the fit is great - and I think that's probably the most important aspect on par with sound, which I also love. Battery life has been brilliant and more than adequate. Been roaming central London previously and Heathrow airport as well as HK for the day and had zero dropouts so far.