Oscar Munoz, the chief executive who guided United Airlines’ turnaround, will relinquish day-to-day oversight of the company to his handpicked successor.

United president J. Scott Kirby, whom Munoz recruited in 2016, will become chief executive in May, the Chicago-based carrier announced Thursday. Munoz will transition to executive chairman.

With United “in a stronger position than ever,” the time is right to pass the baton, Munoz said, adding that no one was better equipped than Kirby to take the airline forward. “It has been the honor of my career to lead the 95,000 dedicated professionals who serve United’s customers every day,” he said in a news release.

Munoz, 60, was thrust into the top job in 2015, after then-chief executive Jeff Smisek was forced to resign in the midst of a federal corruption probe. His tenure has been marked by both personal and professional challenges. He suffered a heart attack weeks into his new job, and later underwent a heart transplant. He returned to an airline struggling on both financial and customer service fronts.

Then came the infamous removal of a passenger that sparked a global backlash. When David Dao refused to give up his seat on an overbooked flight at Chicago’s O’Hare International Airport in April 2017, security officers dragged him through the aisle. Video taken by other passengers and shared widely on social media showed the Kentucky doctor screaming as he was removed from the aircraft and then again when he suddenly returned to the plane, looking confused, his faced bloodied. He was left with a broken nose, a concussion and had two teeth knocked out. Dao later reached a confidential settlement with the airline.

United’s stock price tumbled and Munoz’s attempts to tamp down the furor only made things worse. He was criticized for the coldness of his and the airline’s initial response to the incident. He later gave up his annual bonus when United decided to link incentive payments to customer service improvements in the wake of the scandal, the Chicago Tribune reported.

The airline implemented a number of changes after the incident, including offering larger travel vouchers to passengers who voluntarily give up their seats. It reexamined its policy on overbooking — selling more seats than are available on a flight — and said airline personnel would no longer call outside law enforcement officials to remove passengers from flights unless it was a safety or security matter. Other airlines made similar pledges.

In recent years, United has undergone a massive turnaround as it jettisoned some less-trafficked routes and increased capacity in major hubs. It pulled in $2.5 billion in profits in 2018, up from $2.1 billion in 2017. United and its United Express brand operated more than 1.7 million flights ferrying more than 158 million passengers last year.

“Oscar became CEO at one of the most challenging points in United’s history, and his focus on putting customers and employees first has transformed United’s culture today and successfully positioned the company for tomorrow,” United Chairwoman Jane Garvey said in a news release. She will retire from the board when Munoz takes over as executive chairman.

The company said Kirby, 52, has “played a pivotal role in enabling United’s cultural transformation and successfully executing the company’s strategic growth plan.”

Munoz recruited Kirby days after American Airlines dropped him as president. “When he arrived, United was a hot mess,” travel analyst Henry Harteveldt told the Associated Press. “Scott has focused on improving United reliability and productivity, and it’s a much more reliable airline than it used to be.”