US Airways (search) is looking for volunteers within its labor force to help employees scheduled to work at Philadelphia's airport over the New Year's weekend in order to avoid a repeat of a Christmas fiasco that left the airline with too few workers to fly its planes and process baggage.

"This is a volunteer program. You will not be paid if this is on your day(s) off," a memo to employees said. "It promises to be a rewarding opportunity to learn more about the operation of our airline and come face to face with our customers."

US Airways spokesman David Castelveter emphasized Wednesday that employees scheduled to work will be paid.

Separately, the airline warned employees it would review the attendance records of those who called in sick over the Christmas holiday — and to discipline workers who abused the sick time system.

US Airways Group Inc. (UAIR) canceled hundreds of flights in the days around Christmas when an unusually large number of flight attendants and baggage handlers failed to show up for work, crippling a flying operation already hampered by days of bad weather.

The debacle left an estimated 10,000 undelivered bags at Philadelphia's airport and stranded travelers along the east coast. Many vowed to never again fly the airline, which is trying to emerge from bankruptcy.

In a message to its employees Tuesday, US Airways sought volunteers willing to give up their New Year's Eve plans and work in Philadelphia. It said they could expect to be used as customer greeters, ramp agents or baggage sorters.

In a separate note, the company said it would conduct an "enhanced review" of each worker's attendance record from Dec. 23 to Jan. 3 to determine who should be disciplined, or denied pay, because of the spike in sick calls.

Also Tuesday, the president of the US Airways unit of the Association of Flight Attendants (search) posted a message on the union's Web site chastising workers who failed to report to work over the holidays.

"By now, we have all seen the reports on the news about the operation of our airline over this past holiday weekend, and how that operation failed miserably. This was caused, unfortunately, by a minority of employees who appear to have decided to take some type of action against the company," wrote Perry Hayes.

"Sadly, the employees who took this action may ultimately cause the failure of the airline."

US Airways is struggling to stay afloat and has asked its major unions to accept large pay cuts if the airline is to survive. A bankruptcy court judge temporarily slashed the pay of all workers by 21 percent in October.

Several unions, including the ones who represent flight attendants and baggage handlers, have been in negotiations over permanent pay cuts, leaving many employees bitter about their future with the airline.

Union leaders have denied there was any organized effort to get workers to call in sick, and some dispute that this year's sick calls were much different from those around any other holiday.

Mollie McCarthy, the president of the Association of Flight Attendants chapter in Philadelphia, said 238 flight attendants called out sick on Christmas Eve this year, compared to 261 in 2003. She said 306 called out sick on Christmas Day this year, compared to 298 in 2003.

"We love this company. It is our home. It is our family," McCarthy said. "This time, the public is blaming us. We're their neighbors. We are the people who help them on the airplane. And they don't trust us anymore."