Finnish fighter jets which flew through the volcanic dust covering much of Europe suffered damage and the air force warned Friday the cloud could have a significant impact on planes. The air force F-18 Hornet jets were on training flights in northern Finland on Thursday morning, when airspace was still open, and the engines were later found to contain fine, volcanic ash dust. "Based on the pictures, it was discovered that even short flights in ash dust may cause significant damage to an airplane's engine," the Finnish Defence Forces said in a statement. Images taken inside one Hornet engine with...