Munoz, who took his current position in September 2015, previous year earned a base salary of $1.25 million, plus stock awards and equity payments for a total compensation package of $18.7 million.
But United said on Friday in a securities filing that management and the board "take recent events extremely seriously" and will link executive bonuses partly to "improving the customer experience".
The airline sparked public outrage last week when a passenger, Dr. David Dao, was forcibly dragged off an overbooked flight after refusing to give up his seat to a United employee. "As a result, the Second Amendment also modifies the definition of "Good Reason" such that the appointment of a Chairman of the Board other than Mr. Munoz, Robert A. Milton or Henry L. Meyer III would not constitute "Good Reason".
Munoz offered a more honest apology that the company was wrong and said: "No one should ever be mistreated this way". Munoz received a total of $18.7 million, including $6.8 million related to replacing his equity stake that he held when he was president of railway CSX. Thune and Nelson said in a joint statement, "We find any further delay in getting necessary answers unacceptable", USA Today reported.
United did not immediately respond to requests for comment.
The Chicago Department of Aviation's response letter from Commissioner Ginger Evans, sent Thursday but inadvertently dated April 27, asked for an extension until Wednesday.
"We are in the process of gathering the full set of facts about this incident and finalising a thorough review of our policy", he wrote.
A lawyer for the Kentucky doctor who was dragged from a United Express flight says it's too late for the airline's CEO to apologize face-to-face and that his client intends to file a lawsuit.
"I'm proud that Ginger suspended three individuals involved in the situation", Mayor Rahm Emanuel said Friday at an unrelated news conference.
"This awful situation has provided a harsh learning experience from which we will take immediate, concrete action".
In a statement to PEOPLE regarding the pending lawsuit, United Airlines said: "We can not apologize enough to Dr. Dao for the shameful way in which he was treated". Henry Meyer was named nonexecutive chairman at the time.