United named Brett J. Hart, the airline’s executive vice president and general counsel, as acting CEO effective immediately.

Hart takes over management of the airline during the recuperation of CEO Oscar Munoz, who had a heart attack on October 14, which United confirmed in its statement this evening. Munoz is officially on a medical leave of absence.

In a statement Hart said, “Oscar’s agenda is focused on customer service, teamwork and innovation and I, along with the executive team, will continue to move quickly to implement it. We believe strongly that we can continue to make steady progress on increasing shareholder value by working together to deliver a great product to our customers.”

According to United, the board of directors remains actively engaged in preparing for all potential outcomes regarding the company’s leadership structure.

Public companies are required to provide material information that may affect decisions to invest in the company, and United filed an 8-K with the Securities and Exchange Commission early Tuesday morning.

Henry L. Meyer III, non-executive Chairman of the Board, had stated earlier Monday that United “anticipates it will today conclude the corporate governance process necessitated by the hospitalization of President and CEO, Oscar Munoz. The company expects to release more details either later today or tomorrow.”

Munoz’ tenure as CEO at United to date has been short. He was named to the position on September 8 after then-CEO Jeff Smisek was forced to resign along with two other executives following an investigation into the airline’s contracts at Newark International Airport and a growing scandal around “the chairman’s flight,” a weekly roundtrip flight serving the weekend home of the Port Authority of New York and New Jersey.

Munoz quickly focused on improving the airline’s battered reputation among employees, frequent flyer members, and the traveling public, visiting many of the airline’s hubs as well as maintenance facilities to meet with employees. In a letter to United workers, he told them “it was time for a new day.” In his email to MileagePlus members, Munoz said “we can do better.” And in a bid to woo the public, United took out full page ads in newspapers and put Munoz on YouTube to say it hadn’t lived up to expectations and created the website UnitedAirtime.com, which solicited questions from potential travelers which Munoz agreed to address.

United CEO Timeline:

Photo Credit: Press image of Brett J. Hart. United Airlines