The incident is the latest embarrassment for a US carrier over how it has treated a customer.
The clip, posted to Facebook on Friday by a bystander on the flight, shows a woman in tears with a young child in her arms, and a man emerging from his seat to confront a male flight attendant.
Facebook user Surain Adyanthaya, who put the video on his page, said in his post that the flight attendant had forcefully taken the stroller from the woman, hitting her with it and just missing her child.
“You do that to me and I’ll knock you flat,” the unidentified man tells the flight attendant.
The crew member then points his finger angrily and challenges the passenger to hit him.
The incident started over a dispute as to whether the woman could bring her stroller on the flight, Scott said.
In the video, the woman with the child can be heard asking flight attendants for the stroller.
American Airlines was investigating Friday’s incident, which happened on Flight 591 from San Francisco to Dallas before the plane took off, Leslie Scott, an airline spokeswoman said.
“What we see on this video does not reflect our values or how we care for our customers,” the airline said in a statement late on Friday.
“We are deeply sorry for the pain we have caused this passenger and her family and to any other customers affected by the incident,” the airline said.
The woman elected to take another flight and was upgraded to first class with entire family, the airline said.
“The American team member has been removed from duty while we immediately investigate this incident,” the airline stated.
Less than two weeks ago, United Air Lines found itself in a public relations nightmare when a video appeared online showing a 69-year-old doctor being dragged off one of its flights to make room for a crew member, sparking international outrage and policy changes by the airline.