We have received the NOA which states that my husband has been extended for 1 year however did not receive the Biometrics letter as of yet. This is the question.

It looks like we are headed for divorce and he is headed back to his country. If he does not appear to the Biometrics appointment what happens to the extension? Would he be alowed to enter (of course assuming is whithin the 1 year mark)? Should I as the sponsor send a letter to them? Or just by not showing up the extension is NULLED and the application is cancelled?

PLEASE HELP ME!!!

Missing a biometrics appointment can and does cause USCIS to start deportation proceedings, or if alien is out of country, they can void the extension letter.

Agreed. To avoid bad consquences if you all changed your mind about divorcing or try it out...is better that s/he cut things here in the good manner. The application can get denied (most likely) if your spouse miss the biometric appt. After that then probably a RFE can be sent or just the notice about denied and that your spouse will be put in removal proceedings...but if your spouse is outside the country...and decided to go back...then it can be found inadmissible. So is better, that if your spouse wants to abandon the application, better s/he surrender the green card to the embassy in his/her country and send a letter to USCIS withdrawing the application and that s/he not longer wants to be a LPR.