A Boeing 777 airliner on Friday made an emergency landing in Moscow with engine problems, the operating airline said, days after another model rained down engine debris over the United States. "During cargo flight No. 4520 from Hong Kong to Madrid, incorrect operation of the engine control sensor was discovered," airline Rossiya told AFP in a statement, adding that "the crew decided to make an emergency landing in Moscow." Online flight trackers confirmed the flight was carried out with a Boeing 777. jbr/mm/lc