Jad Mouawad And Nicola Clark New York Times News Service

As Europe grounded most airline flights for a fourth day on Sunday because of a volcanic ash cloud spreading from Iceland, increasingly desperate airlines ran test flights to show that flying was safe and pressed aviation authorities to loosen the flight ban.

As Europe grounded most airline flights for a fourth day on Sunday because of a volcanic ash cloud spreading from Iceland, increasingly desperate airlines ran test flights to show that flying was safe and pressed aviation authorities to loosen the flight ban.