Wet Sock Smell

Hey guys,

I was reading an interesting thread on APC and the question and concerns of a “wet sock smell” came up.

To my understanding, it only happens when you run the packs from the bleed air (and just about every plane is designed that way). Some said it was mold in the filter and some said that it was a leaky APU so it’s actually a oil that into the bleed air system.

From what I’ve read, some people have gotten pretty sick or even lost medicals over it.

Either way, being that 319/320 and 145 are heavy offenders of this (again, from what I’ve read), I was hoping you guys could shed some light on this topic?



First, the packs always run off the engine bleeds and also I’ve had oil leaks and that’s a very different smell (smells like burnt oil). I’ve read the articles and yes occasionally I’ve encountered a musty smell. I don’t know anyone who’ve gotten sick from it and have always been told it’s from older musty packs/ducts.



Bleed air is the only way to run the packs. I have not smelled this smell a single time. Sometimes I think people just make this stuff up.


Thanks for the reply and it’s a relieve that it’s not as bad as some people make it out to be!