The acronym went away a couple of years ago just now known as Nadcap, Madcap and #%## these days.
It is a program administered by PRI an non profit entity under SAE.
Primes such as AirBus, Boeing, Goodrich, and others now use this program to address the approval of suppliers performing special processing for them.
While in the begining there were actual standards created for the audits these have gone away you you just now have the checklists themselves.
These are the compilation of what the primes want to have verified. Some of the discussion on what some though were important vrs what others thought was very "intresting". Still lots of discussion on getting out of the "raising the bar" actions and removing these types of questions from the checklists. The dirrective is to all the task groups to make it so but some are slower than others.
You have the base checklist and some sub checklists and depending on the process you can have suplemental checklists that ask questions specific releating to requirements of one of the primes. Most of the auditors have no love for these suplemental checklists and I think that the individual primes should have to deal with them on their own but that is a battle for those above my pay grade. I do not have to deal with them at my location since except for corprate desires and the vauge flowdown in the AirBus Gress program there is no contractual requirement.
We do find that we do get a benifit from haveing a knowldgeable auditor come in and look under the rocks to keep us on our toes. Just human nature to "drift". We get more out of these audits then the AS9100 we go thru.