I have a friend in B.C. that is a guide, he uses an Airdale for Bear hunting. Fairly common up there, and in fact last spring he was helping the owner of a sporting goods shop train his Airdale.
From what I gather, since bear as so common up there, they don't want to use a hound type ( blue-tick, red-bone, etc. ) that will scent a bear, then take off, barking, resulting in a long chase. With the Airdale's ( and others like them ), they drive around, spot the bear, and if they want to go after it, they release the dog, it closes in quietly, then goes after the bear, causing it ( usually ) to get up a tree right away, with no long chase.
Mark