I sincerely apologize if this has been answered previously (but I couldn't find it)...As a CO Platinum I will be flying a couple of segments on NW (ticketed & equipment) in mid Nov. As I rarely fly NW I wasn't sure if they too had a EUA system or if I had to call CO or NW 3 days before for my upgrade. (At this point, there appears lots of F seats on all 4 segments).