Sean Durfy’s imminent departure from WestJet, where, as President and CEO, he led it through a complex period of evolution, will be a considerable loss – as investors clearly thought, this week driving the company’s share price down steeply yesterday. The airline is on the brink of leaping into a more global role, having emerged from being a small western Canadian low cost airline over the past decade. His replacement, Gregg Saretsky, is well qualified to cover the international side of WestJet’s evolution, having spent much of his previous time with Alaska sewing up and overseeing airline alliances.