Originally Posted by

**JohnnyP**
I wonder if they would ever bring back mainline service from ORD (don't laugh) [to COS].

I am having lots of trouble understanding the rationale for increasing ORD/COS and reducing DEN/COS and DEN/ORD. Arguably, higher fuel dictates switching to the mainliners out of DEN.

But assuming there is a rationale for more nonstop COS/ORD and less COS/DEN/ORD, higher fuel costs would eventually dictate a return of mainline to COS, but what would UA use? Doesn't seem like there would be enough demand to fill 757s, and the 3xxs will be needed for mid haul routes once the 737s are all parked. UA is adamant about not buying newer, fuel efficient planes.