A Lufthansa Boeing 747-800, registration D-ABYA performing flight LH-402 from Frankfurt/Main (Germany) to Newark,NJ (USA), was enroute at FL340 about 150nm northwest of Shannon (Ireland) about to enter the Oceanic Crossing when the crew decided to return to Frankfurt reporting a medical emergency. The aircraft descended to FL330 and landed safely back in Frankfurt about 2:15 hours later. A passenger reported the captain announced the first officer had become sick and the aircraft would need to return to Frankfurt. The occurrence aircraft remained on the ground in Frankfurt for 19 hours before resuming service. On Mar 15th 2017 Germany's BFU reported in their September 2016 bulletin, that no investigation was opened into the occurrence even though rated a serious incident.