Massive aerial battles — mock ones, fortunately — are raging over Cold Lake, Alta., as more than a dozen countries participate in one of the world's largest military air exercises.

Pilots from all over the world are taking part in the annual "Maple Flag" training campaign at Canadian Forces Base Cold Lake. The four-week event, which Canada has hosted since 1978, aims to bring armed forces together to better prepare for joint interventions in potential conflicts.

CBC's Briar Stewart took to the sky over Cold Lake and got a bird's-eye view of this unique international exercise.