Dale Seto is accustomed to toiling out of the spotlight. Most days, the aircraft mechanic crawls around inside the guts of an Airbus jetliner, grease on his hands. “We’re kind of the underdogs,” says Seto, 57, who has worked for Air Canada for the past two decades. “But in my opinion, we perform the most important function in the entire airline industry, and that’s making sure that the planes are safe and ready to fly.”

Hundreds of thousands of lives depend on the quality of work done by Seto and his colleagues, but he says the industry’s perennial woes means they haven’t had a pay raise in nearly a decade. That helps explain why he and12,000 Air Canada employees represented by the International Association of Machinists and Aerospace Workers jealously guard their defined benefit pension plans, an increasingly rare species of retirement income in the private sector. More than just a perk, defined benefit plans—in which the employer guarantees retirees a certain level of benefits—are viewed by workers as a key element of overall compensation. Continue…