A Japan Airlines domestic flight returned safely to Tokyo on Wednesday after the pilot shut down an engine due to unspecified trouble while en route to Hokkaido in northern Japan. The airline said that JAL Flight 521, carrying 228 passengers and 11 crewmembers, landed at Haneda airport, and that no injuries or damage was reported. JAL said the pilot shut down a right-side engine on the Boeing 777-200 after cockpit indicators showed trouble in it. Fire engines stood by as a precaution at Haneda, but no fire or smoke was seen, AP reported. The cause of the engine trouble was under investigation.