A man trying to get home to see his wife and kids has been kicked off a plane after urgently needing to use the bathroom.

Kimi Hamilton was travelling from Atlanta to Milwaukee on a Delta Air Lines plane when he urgently needed to use the toilet as take-off proceedings were underway.

In fellow passenger Krista Rosolino's view, Hamilton's removal from the April 18 flight was an outrage and so was everyone else's forced exit from the plane when it returned to the gate in Atlanta. She took to social media to defend a man she didn't know.

The Delta Air Lines quick-take on this incident is that federal law requires passengers to comply with crew instructions or run the risk of being seen as a security threat.

"Our flight crews are extensively trained to ensure the safety and security of all customers," Delta said Wednesday in a statement. "It is imperative that passengers comply with crew instructions during all phases of flight, especially at the critical points of takeoff and landing."

It is the latest in a number of airplane incidents which have occurred in recent weeks.

A doctor was dragged off a United Airlines plane in Chicago earlier this month when he refused to give up his seat to make room for airline staff on a crowded flight.

And a confrontation erupted Friday on an American Airlines jet in San Francisco after a flight attendant snatched a pram from a passenger and her baby.

Both incidents were captured on video, as were two Delta attendants' attempts to eject Hamilton from the plane.

When he refused, the entire aircraft was emptied and all passengers except Hamilton were allowed to re-board a short time later.

Hamilton was travelling alone. Rosolino and her husband, Mike, both lawyers in Milwaukee, were sitting with their infant daughter across the aisle from him.

They told WLTX19 that the plane taxied to the runway and the passengers were told it was third in line to take off. This is a time when you're supposed to remain seated, but the wait extended to about 30 minutes.

Hamilton needed to use the bathroom but decided to wait it out. "We weren't taking off. We were still. The plane isn't moving," he said. "I don't remember drinking an abnormal amount of water," Hamilton said.

He walked to a restroom at the rear of the plane. A flight attendant there said if he used the restroom they would lose their place in line. So he sat back down, but the urgency grew stronger.

Hamilton returned to the restroom, and this time went in and quickly did his business.

"The pilot came on and said, 'Ladies and gentlemen, I'm sorry for the inconvenience, but we have to return to the gate and remove a passenger,' " Hamilton said. "It escalated to that point that fast."

Two Delta agents, first one and then another, approached Hamilton and told him to get his things and exit the plane. He said he knew they wouldn't let him back on, so he refused.

"It was already understood and decided that I was a problem and I was getting kicked off the plane. When I exited there were FBI agents waiting for me with Delta personnel," he said, adding how thankful he was that Mike Rosolino stood by his side throughout.

Hamilton said he remained calm both on the airplane and during questioning at the terminal. He thinks that saved him from getting arrested for causing a disturbance or interfering with the flight.

Delta refunded part of his ticket cost and left him to find his own way home.

Delta gate agents said his checked luggage would be waiting for him in Milwaukee. He bought a walk-up ticket on a Southwest Airlines flight, at a cost of three times the refund he had received, and arrived home about 11 that night, several hours later than he had planned.

A passenger from a different Delta flight told Krista Rosolino that two passengers needed to use the restroom while the plane prepared to taxi, and in that case the flight attendant simply told the pilots to wait until those passengers were done.

Other passengers were sympathetic toward Hamilton. When everyone was forced to leave the plane, some talked about staying put in a show of solidarity.

Hamilton said he apologised to a man sitting next to him for the inconvenience. "You did nothing wrong," the man replied.