There were no injuries in the Feb. 19 incident involving Flight 268 from Los Angeles to London, although the flight crew did declare an emergency and landed early. British Airways told the International Herald-Tribune the Boeing 747 was operated within safe limits.
FAA spokeswoman Laura Brown also told the newspaper the U.S. agency would "pursue every legal option available to us."
The FAA said the BA crew should have returned to Los Angeles when the engine trouble developed shortly after takeoff. Because the jet had only three working engines, it had to fly much lower than usual, causing a higher rate of fuel consumption. That led to the crew declaring an emergency and an early landing at Manchester, the IHT said.
While a U.S. official said the allegations are "an indictment of the safety culture of British Airways," BA's Steve Shelterline told the newspaper the company's pilot took actions allowed by FAA regulations.