A passenger on Delta Flight 100 recorded a scary moment when the cabin appeared to fill with fog while waiting on the tarmac.
Passengers who were flying from Jacksonville to New York on Sunday night were alarmed.
Amanda Goncalves was a passenger on the flight.
Goncalves said there was no odor, but the fog lasted for 30 minutes as the plane sat on the tarmac before takeoff.
"People were wondering why it was lasting so long but ... the flight attendants didn't really make an announcement. (They joked that) they were practicing for their Halloween haunted house ... instead of saying it was from the humidity or condensation," Goncalves said.
ActionNewsJax showed the video to its aviation expert, Wayne Ziskal, who believes the fog was condensation. He said it's not uncommon on a hot, humid day for mist to pour from air conditioning vents.
"We have our weather situation down here from the point of high humidity and the temperatures that we have in the summertime. If you are a regular flyer, this is something you might see that would last 30 seconds when they change air condition(ing) systems," Ziskal said.
But even he was surprised that the passengers said they were never told what it was.
"I think we as crew members and pilots need to put ourselves in the position of, 'This is somebody's first time on an airplane and they see this, what do they think?'" Ziskal said.
Ziskal said passengers should always report anything unusual while on an aircraft, whether it's their first time flying or not.
The flight from Jacksonville to New York landed normally.
A Delta spokesperson said the mysterious fog didn't pose a danger to passengers.
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