US Airways (search) started delivering luggage to passengers Sunday after suffering what its chief executive called an "operational meltdown," while Comair put some of its passenger planes back in the air a day after canceling all of its 1,100 flights.

US Airways ran two baggage-only flights from Philadelphia to its hub in Charlotte, N.C., as it continued to pare down its mountain of backed-up luggage, caused by severe weather Thursday and large numbers of baggage handlers, ramp workers and flight attendants calling in sick.

The airline, operating at near-normal levels, canceled 43 of about 1,200 flights systemwide on Sunday, down from 143 on Saturday and 176 on Friday.

In a memo to employees, US Airways chief executive Bruce Lakefield thanked those who helped "our customers during the operational meltdown we experienced over the weekend." However, he criticized those who exacerbated problems by calling in sick.

"I have seen lots of excuses for why people took it upon themselves to call in sick, such as low morale, poor management, anger over pay cuts and frustration with labor negotiations," Lakefield said. "None of those excuses passes the test. We all have our jobs to do."

Union leaders representing workers in negotiations with the airline over further pay and benefits concessions denied any organized effort to slow operations.

"It's poor management planning, that's my opinion," Teddy Xidas, president of the Pittsburgh branch of the Association of Flight Attendants (search), said Saturday. "We have sick calls every single year around the holiday."

Meanwhile, Comair (search) ran 110 to 165 flights Sunday, or 10 to 15 percent of its normal flight schedule, a day after canceling all flights when its computer system was overwhelmed by cancellations and delays caused by a winter storm in the Ohio Valley Friday night.

"We anticipate Comair will be able to operate on a full schedule by Wednesday," said Nick Miller, spokesman for the Delta subsidiary based at Cincinnati/Northern Kentucky International Airport.

The airline carries 30,000 customers to 118 cities on a typical day. Passenger numbers increase slightly during the holidays, but Miller said he did not know exactly how many people were affected by the cancellations.

Some Comair customers were able to get to their destinations Sunday. Jackson and Julie Lashier were booked on a Delta flight to Minneapolis after their flight to Des Moines, Iowa, was canceled. Relatives picked them up at the airport.

"We feel very fortunate that we are able to get out today," Jackson Lashier said. "A lot of people here today are under much worse circumstances."

U.S. Department of Transportation spokesman Robert Johnson said Sunday that federal officials were monitoring the progress Sunday with US Airways and would investigate what happened at Philadelphia International.

US Airways, which is operating under Chapter 11 bankruptcy protection, approved a new contract with its reservations and gate agents Thursday that slashed pay by 13 percent. The airline is seeking deals with flight attendants and machinists that it says it needs to drastically cut labor costs to survive beyond mid-January.