Most passengers on an airliner never even look out the window, but about 300 people on a commercial flight bound for Japan are lucky that U.S. Air Force Staff Sgt. Bartek Bachleda, who works with the 909th Air Refueling Squadron, was paying attention.

Shortly after takeoff from Chicago, Bachleda noticed what appeared to be a plume of fuel leaking from the left wing. He told a flight attendant about the apparent leak, but at first got an unconcerned response. Then he told her it was an emergency, and showed her the video he had shot from his seat.

"She was completely serious and was no longer handing out drinks," he said. "I told her you need to inform your captain before we go oceanic."

The captain came into the cabin to check out the leak and said the cockpit crew had been aware that fuel seemed to be burning too quickly. He diverted the flight to San Francisco, where most passengers were able to catch another flight to Japan.

Bachleda and a coworker were asked to stay aboard while the passengers were deplaned. They waited for the arrival of investigators and officials, and participated in the debriefing about the situation.

"When we got off the airplane everyone was thanking us," said the sergeant.

The two airmen were put up in a hotel overnight and flew to Japan the next morning. The airline bumped them up to first class, the Air Force said.