small jetliner made an emergency landing on Wednesday after a passenger looked out his window and spotted something alarming: fuel leaking from a loose gas cap.

"He looks out on the wing and just sees fuel just flying out of the wing," another passenger, Richard Henson, told WRCB, the NBC station in Chattanooga.

Here's what the passengers saw when they looked out the window of American Airlines flight 2762, operated by ExpressJet.

The plane, a CRJ-200 carrying 41 passengers from Chattanooga to Dallas-Forth Worth, made the emergency landing in Huntsville, Alabama, without incident.

Henson said passengers could smell the gas as they got off the plane, and that airline staff explained what went wrong.

"Whoever the person in charge in Chattanooga that did the fuel fill on that side of the plane, did not put the cap back on correctly or properly," Henson told WRCB.

Roger Nunamann, a pilot not involved in the flight, said the passengers were never in danger.

"It's not the first time it's happened and it wont be the last time it's happened," Nunamann told WAAY TV, the ABC station in Huntsville. "I've never known it to cause any kind of fire or catastrophic failure or crash."