A320neo and A321neo noise levels

Yesterday the A321neo with the CFM LEAP-1A32 engine was certified by both the EASA and the FAA. The EASA certification document for the aircraft family can be accessed here, the noise certification document is here. The FAA documentation is not online yet.

What strikes me is the high noise level of the A321-251N. The LEAP-powered A321neo is not really less noisy than the CFM56 powered A321ceo, which itself was considerably louder than the V2500 powered A321ceo.

If you compare the highest MTOW version (93.5t) you get a cumulated noise level of 281.7dB for the A321-251N, the A321ceo with the  CFM56-5B4/3 is certified with a noise level of 280.1dB (there are also versions of the CFM56 which have higher noise levels than the LEAP1A though.

The PW1133G in comparison has a cumulated noise level of 268.5dB, more than 13dB less than the LEAP-1A32. Both at the lateral and flyover noise points the GTF is less noisy by about 6dB, the approach noise, where the aircraft itself is the main source, is almost the same for both versions.

I wonder if the values for the LEAP-1A32 are real – or somebody at EASA put some wrong numbers in the document.

The noise values for the A320neo are telling a complete different picture: here, the LEAP powered A320-251N is better than the PW1127G powered A320-271N by 1dB, mainly through lower levels at the lateral noise point.

I wait for some good explanations...