Boeing 737 ambient noise during ascent

[paulkinm]

Hi all,

I have noticed that while the aircraft is ascending, the ambient noise from within the cabin increases, especially around the 20,000ft and onwards mark.

From what I can tell, the engines appear to be at a constant thrust but the noise increases. Is this due to the air getting thinner the higher the aircraft goes?

Cheers

[Veruka Salt]

Hi Paul,

Possibly the noise of increased airflow as speed increases. I notice changes in cabin noise levels when accelerating or decelerating to/from 250kts below 10000ft, and again when slowing to configure for approach.

Hope this helps.

[Rainboe]

The cabin noise certainly seems to decrease markedly in the 737 at 39,000' and higher. Becomes lovely and peaceful up there.

[Smudger]

My 73 only goes to 37000 so I wouldn't know.....

[Chille Con Carnie]

Smudger,try a NG rather than a red & silver one your notice a few changes. Even the Ng,s are getting old ?

[Capn Bloggs]

It would have to be related to pressurisation. IAS reduces as you climb above the mach-changeover point, which means less particles per second banging on the windows and therefore less impact noise. Hence the comment by Rainboe (bragger! ).

[Denti]

Going from a CI of 35 to a nice low CI of 10 made a lot of differences, flying is relaxing and quiet in the Classic now (except for the screaming of those flying behind us).

[JediDude]

Originally Posted by Capn Bloggs

less particles per second banging on the windows and therefore less impact noise.

There will also be less particles to transmit the vibrations from the engines to the fuselage.

[BitMoreRightRudder]

Just turn the recirc fan off.

Had to come back from FAO at .65 the other day, now that was peaceful!