By Rick HowlettAs more passenger flights are taking to the skies over Europe this week, Louisville-based UPS Airlines is trying to clear its backlog of air shipments to and from the continent.The volcanic ash cloud from Iceland forced the carrier to close its European air hub in Germany to traffic last Thursday and send some flights into Spain.Spokesperson Mike Mangeot says the Cologne facility has reopened and UPS has resumed a full flight schedule in and out of Europe."Our customers may continue to experience some delays on the European shipments, but things are looking much better than they were a couple of days ago," he said.Mangeot says officials continue to monitor the volcanic activity in Iceland and have a contingency plan in place should there be another major service disruption.