Delta Air Lines (DAL 1.25%) CEO Ed Bastian is in search of a new copilot following the Friday decision by CFO Paul Jacobson to retire after more than two decades with the airline.

Jacobson, though just 48, joined Delta in 1997 and was named chief financial officer in 2012. He worked in the company's finance office during Delta's 2005 to 2007 bankruptcy, and the subsequent merger with Northwest Airlines.

A group of Delta employees at a ribbon cutting for a new plane.

Image source: Delta Air Lines.

In the years since, Delta has been among the most innovative companies in the airline industry, revamping its pricing strategy to better-compete with discounters, buying stakes in foreign partners to gain international exposure and solidify alliances, and even investing in a refinery to ensure a steady supply of jet fuel.

"Paul played a crucial role in Delta's bankruptcy process and the strategy that led Delta to regain our investment-grade balance sheet while also investing billions in our people, product and service," Bastian wrote in a memo to employees that was released by the company.

Jacobson will not be leaving immediately. Delta said he has agreed to stay on until a successor is named and through a transition period.