The bags will be checked through. Your friend should make sure the AA
agent knows he is connecting to UA
so that they can edit in the necessary flt information on the luggage tags. Your friend should also double-check his claim tags to ensure the bags are checked through.
Hopefully there is a long enought layover in ORD
for the bags to make it. I don't know how much time is needed to interline in ORD
, but it is generally more than when connecting to the same airline.