hapter 3 noise >>> chapter 4 in usa?

[groundbum2]

It's 2005 in BW1 and I'm using a lot of cheap b737-400s but they are chapter 3 noise. Will the USA go to chapter 4 and does anybody know when approximately? I'm up to 58 aircraft but don't want to dig a deep deep hole for myself by going down the chap3 route however cheap they are!

Thank you,

Simon

[Zobelle]

Haven't seen chapter 4 req even on bw2.

I think you'll be fine.