STRESSING THE SYSTEM: United made a lot of changes over the summer as it integrated Continental, hurting its on-time ratings and annoying passengers.

FIXING IT: United is adding spare planes and staff, and trying to streamline the software that ticket agents use to check in passengers, among other things.

CEO APOLOGIZES...AGAIN: "We hold ourselves to a higher customer service and reliability standard than we delivered for our customers lately," Jeff Smisek said.