USAir said it has been forced to...

USAir said it has been forced to cancel more than 150 flights since Sunday because many flight attendants have refused to work overtime. The carrier, with headquarters in Washington, said the cancellations, which primarily have occurred at its Pittsburgh hub, will continue until today. Spokesman David Shipley said passengers have been delayed and some have not been able to get to their destinations, but he said there was no “mass chaos.” Eighty-one of USAir’s 1,600 daily city-to-city flight legs were cancelled on Sunday, he said. On Monday, 61 of the 1,600 flight legs were canceled, and Tuesday morning, 20 more legs were canceled.