I have trip credit, and I wanted to book an international trip - when I check the itinerary, AA is the originating flight from my local city to Chicago - but from Chicago to the middle east it is on Etihad airlines and the return ticket is by Etihad as well. Can the trip credit be used in this case since the originating leg is AA? or every flight leg needs to be operated by AA for the trip credit to be used? Any idea. Thanks.