1.   The refueling problems appear to be unique to USAir.

2.   Earlier Sunday, another Concorde was unable to take off from Heathrow because of a refueling problem, the airline said.

3.   Earlier in the day, a Concorde was unable to take off from Heathrow because of a refueling problem, the airline said.

4.   The following day, the first flight to New York was delayed by a refueling problem.