A U.S. Air Force refueling jet has landed safely at its base in England, RAF Mildenhall, after an in-flight emergency, the Air Force unit that operates the aircraft said on Wednesday.

The Boeing KC-135 Stratotanker with call sign QUID 72 returned safely at 1:20 a.m. (0020 GMT), an hour after the emergency, according to a statement from the 100th Air Refueling Wing.

"The in-flight emergency was associated with a flight control-related malfunction; however, the crew and aircraft were never in jeopardy," a spokeswoman for the unit said in an emailed response to questions.

The jet was on a routine air refueling mission and had three crew members on board as well as three additional military passengers, she said.

RAF Mildenhall, in Suffolk, eastern England, had been its planned destination.