Originally Posted by RobOnLI
Furthermore, I believe upgrade availability is different for "direct" flights that have a stop. Having R availability on both CLT-DTW and DTW-IND isn't enough...there must be specific R availability throughout. Just because there's EUA seats on both flight separately doesn't mean it's available for the combined flight.
Even worse, assuming both legs are on the same equipment, I'm pretty sure the SAME seat (i.e., 2A, 4B, etc.) has to be free on both legs, since I don't think the computer can assign you to different seats numbers on the two legs of the "direct" flight. You might find a GA who can override that on the battlefield, but I don't think EUA will.