A United Airlines jetliner headed for Los Angeles returned to New Jersey's Newark Liberty International Airport early Thursday after flames were seen near a wing.
Video showed flames soon after Flight 1871 had taken off.
A passenger told WABC-TV it appeared fire was coming from an engine.
"I didn't know what was happening," passenger Gabrielle Guzy said. "My sister said she thought it was lights but I knew it was fire from the engine. I kept reassuring myself we'd be OK because we had only been in the air for a minute."
In a statement, United said the flight returned because of a "mechanical issue." The airline said the flight landed safely and passengers deplaned normally.
The airline was working to get the passengers to Los Angeles.