Dave S wrote:

Again, to agree, saying a
particular plane is drier is peculiar. The only thing I can think that
would explain that is IF the amount of air being exchanged is greater
than in comparison to other aircraft. (i.e. greater leak out, so greater
flow in of dry air, which then escapes sooner, increasing the "dry"
effect).

Perhaps some aircraft are equipped with humidifiers for the inside air?

George Patterson
"Naked" means you ain't got no clothes on; "nekkid" means you ain't got
no clothes on - and are up to somethin'.