United Airlines said its chief executive, Oscar Munoz, will return to the airline full-time on March 14.
Munoz suffered a heart attack last October and has been on medical leave since then. The company had earlier appointed general counsel Brett Hart as acting CEO.
Munoz has been taking active part in major decisions across the company and meeting employees and shareholders during his recovery, United said.
Munoz took over as United's chief executive in September aiming to build morale after years of strained labour relations. He replaced Jeff Smisek, who resigned because of investigations into United's relationship with the Port Authority of New York.
United had the worst customer satisfaction of any North American airline, with the exception of low-cost carrier Frontier, according to JD Power's 2015 ranking.