A woman without a boarding pass or photo ID managed to sneak on to an plane.
The stowaway was only discovered when the real passenger allocated her seat number tried to take her spot.
The woman, identified as Sylvia Rictor, claims she threw away her boarding pass as soon as she got on the plane.
She also tried to convince the Delta Airlines crew a photo on her phone should be taken as ID.
Video footage shows the angry confrontation on board the plane at Orlando International Airport.
Passenger Jenni Clemons told WFTV she called a flight attendant to her assigned seat when the woman refused to move.
Miss Clemons said: "She said very bluntly, 'I'm not moving'."
A row took place between Ms Rictor and the crew, before the pilot called police.
"They eventually told her, 'You're breaking federal law'," Miss Clemons added.
All passengers on the Delta flight 1516, from Orlando to Atlanta, had to then get back off the plane.
The security breach meant they all had to have their boarding passes and IDs rechecked.
The Transportation Security Administration said in a statement: "We can confirm that the individual was screened.
"We are working with law enforcement to investigate the incident at the plane and will not be providing any additional information at this time."
The Orlando Police Department said the FBI was notified about the incident and will be following up.
