David Dao says he's thankful the United incident made the airline fix its policy

Dr. David Dao speaks to 'Good Morning America.'(ABC News)

The Kentucky doctor who was forcibly dragged off a United flight in 2017 said Tuesday that while the ordeal caused him and his family pain, he is thankful it forced the airline to re-evaluate its policies.

David Dao, of Elizabethtown, appeared on ABC's "Good Morning America" on Tuesday, speaking publicly about the ordeal that garnered international attention for the first time in two years.

"Everything happens with a reason," Dao said.

On April 9, 2017, Dao was trying to fly to Louisville from Chicago O'Hare International Airport with his wife when the airline asked the couple and two other passengers to leave the plane to make way for United employees who needed to fly.

Dao, 69 years old at the time, refused to give up his seat and was eventually forcibly pulled off the plane by Chicago Department of Aviation officers.

Videos taken by other passengers showed Dao's face bloodied and his glasses broken as he was dragged down the aisle, resulting in outrage and international scrutiny at how United handled the situation.

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More: United Airlines passenger David Dao was violent before removal, aviation police say

Dao said Tuesday that he found the videos hard to watch in the months after the incident.

"I just cried," he said.

The airline instituted new rules, including never removing boarded passengers unless for safety or security concerns.

United also reached a settlement with the Kentucky doctor for an undisclosed amount.

Dao said he refused to leave the plane because he needed to get back to Kentucky to oversee the opening of a clinic he founded for U.S. veterans.

He started the clinic with his wife as a way to thank American servicemen and women, he said, mentioning he was plucked out of ocean waters by the U.S. Navy as he fled communism in his home country of Vietnam about 44 years ago.

More: Two officers fired after United Airlines dragging incident; another quits

United CEO Oscar Munoz initially characterized Dao as "disruptive and belligerent" but, following public backlash, eventually apologized to the doctor and promised a similar incident would never happen again.

In a statement to ABC News, United said the changes it has made since the incident "better serve our customers and further empower our employees."

"This year, we are focused more than ever on our commitment to our customers, looking at every aspect of our business to ensure that we keep their best interests at the center of everything that we do," United said in the statement. "As our CEO Oscar Munoz has said, we at United never want anyone in the United family to forget the experience of Flight 3411. It makes us a better airline, a more caring company and a stronger team."

The backstory: United Airlines passenger dragged off flight suffered concussion, broken nose

In the days following the incident, Dao's attorneys said he suffered a broken nose and concussion and lost two two teeth while getting dragged off the plane and hitting his head.

Dao said on "Good Morning America" he does not remember anything after bumping his head but later woke up in the hospital with a trauma team surrounding him.

He said the first few months after the incident were "horrible," describing how he was put on suicide watch by hospital staff and later spent months learning to walk again.

Dao, now retired, said he still has sleep issues and trouble with his concentration and balance. While he had run more than 20 marathons before the incident, Dao said he now can only run about 3 miles.

Dao said the United employees who asked him to leave the plane could have explained why he was being bumped from the flight "nicely" and "reasonably."

"That makes a difference," he said.

The Chicago Department of Aviation later fired two officers involved in the incident, with a third officer resigning.

One of the fired officers sued United, Chicago's Department of Aviation and its commissioner in April 2018, alleging he was not properly trained on how to use force.

That same month, nearly 300 Chicago Aviation Police officers filed a lawsuit after the city of Chicago and state of Illinois ended their law enforcement authority at airports.

Asked what he would say to the officers who pulled him off the flight, Dao said, "I'm not angry with them."

"They have a job to do. They had to do it," Dao said.

Dao said he wanted to finally speak publicly about the incident to thank his supporters around the world.

On Tuesday, Dao shared how he made a promise to God to devote his time to charity work if he recovered. Since his recovery, Dao said he helped residents in Texas displaced by Hurricane Harvey and traveled to Vietnam and Cambodia to help install solar power in villages with no electricity.

"Well, the most important thing is the accident turned out the positive way," Dao said.

A timeline: What happened on United Airlines Flight 3411 when David Dao was removed

Actions taken: United Airlines cleans up policies, reaches settlement with David Dao

This story will be updated.

Reach Billy Kobin at bkobin@courierjournal.com or 502-582-7030.

This article originally appeared on Louisville Courier Journal: David Dao says he's thankful the United incident made the airline fix its policy