Originally Posted by
sbm12
While the technical reason above is part of the problem there is a slightly more sinister version as well. A direct flight (single flight number, even if a connection and change of aircraft) historically would show up above a traditional connection in a GDS interface. So searching SAT-GUM would have always listed CO 7 first, even though it was a 737 to IAH and then a 777 on to Tokyo and a 764 continuing to Guam.
Ooh, I hate it when they do that. DH and I once had an MCI-JFK-EDI "direct" that involved a change of planes at JFK as well as a change of terminal, requiring us to go through the TSA mess again. Worse, the MCI-JFK flight got diverted to CVG and when we arrived at JFK (in plenty of time for the JFK-EDI leg) I discovered that DL had trashed our seat assignments from JFK-EDI and DH had lost his aisle seat, which he needed because of a creaky back. A lounge angel changed our assignments for us.
My sinister reason: you don't get mileage credit for the actual miles flown- you get less because they count them as if you'd had a nonstop. If I were in charge of the world it would be illegal to assign the same flight number if an aircraft change is required.