A New York-bound Boeing 747 operated by German airline Deutsche Lufthansa AG turned back in mid-flight Saturday after the pilot reported that one the plane's four engines was leaking oil.

The airline said Saturday that the plane, carrying 334 passengers from Frankfurt to New York, was over Greenland when the pilot made the decision to turn back although the plane could have flown onward to New York's John F. Kennedy Airport on three engines.

Ann Curry, an NBC television reporter, was aboard and provided public "tweets" — brief, instant Internet updates via Twitter — on the plane's turnaround after it returned to Frankfurt International Airport.

She tweeted that the plane "was almost over Greenland when it turned around. Pilot's voice was tense."

Lufthansa said there was an oil leak but flight LH400's passengers and crew were not in danger.

The planed landed around 5 p.m. without problems and the passengers were to set fly on to New York Saturday night.