ANA B788 near Tokyo on Oct 6th 2014, engine oil indication

An ANA All Nippon Airways Boeing 787-800, registration JA823A performing flight NH-941 from Tokyo Narita (Japan) to Dusseldorf (Germany) with 117 people on board, was climbing out of Tokyo with a delay of 4 hours when the crew stopped the climb at FL170 due to a decreasing engine oil quantity indication for the right hand engine (Trent 1000). After working the related checklists the crew decided to return to Narita about 30 minutes later and landed the aircraft safely on Narita's runway 34L about 80 minutes after departure.

The airline reported it is unclear whether the indication was false or there was an actual oil leak. An examination is under way.