Just so that people will stop thinking I am taking pot shots at the A380 there are a few things I would like to say.
First off, this is a rumor section. I heard a rumor and brought it here to see if anybody else was hearing same and to open discussion. To my knowledge, I am not known for spouting lies around here.
Second, Airbus has done amazingly well at getting the noise numbers to where they are for an aircraft that is 30% larger than a 747-400. In the past ten years there have been no significant noise reduction hardware developed and none in the foreseeable future. If those noise numbers posted earlier are correct, Airbus has accomplished an amazing feat vs. the 747 noise levels and I commend them.
For example, the 747-400 at 652,000 approach weight rings around 103.8 EPNdB vs 99.9 EPNdB for the A380. To a layman, that may seem very small, but in the real world that means the A380 is half+ as noisy as the 747-400. -3 dB difference halves the energy of the noise.
As far as noise reduction goes, the entire industry is up against a technological barrier and has been for some time. We can get small reductions here and there or do what Airbus admitted and enlarged the fan diameter (as bypass ratio goes up noise goes down), but then performance suffers. If they truly are in a noise reduction program, it’s the last few dB or tenths of dB that are extremely hard to get. With the technological barriers we have today, that last little bit can be downright impossible.
