GavnTom,
As an LPR he will need to prove that his primary residence, which he does not intend to abandon, remains in the USA. As an applicant for adjustment it may be a bit more difficult, in that he is not yet recognized as having his primary residence in the USA.
I think it would be a good idea to review the details of your plans with an immigration attorny who has experience with abandonment of status issues. Such attorneys can be hard to find (which may give you something to think about with regard to getting your advice on the issue from amateurs).
Yodrak
QUOTE(GavnTam @ Jul 20 2007, 03:17 PM)

I am a USC and my husband is applying for AOS. If we leave the US shortly after he receives his AP and we only fly back for necessary appointments will that cause a problem? We are looking at taking a position with a NGO in Africa for 1 year but are worried they will see that as a conflict to filing AOS.