A Lufthansa Airbus A340-300, registration D-AIFC performing flight LH-600 from Frankfurt/Main (Germany) to Tehran Imam Khomeini (Iran), was enroute at FL370 about 30nm east of Sofia (Bulgaria) when the crew decided to descend the aircraft to FL340 and return to Frankfurt. The aircraft landed safely back on Frankfurt’s runway 07R about 2 hours after the decision to turn around.
A passenger reported the crew announced an engine (CFM56) issue.
A replacement A340-300 registration D-AIGV is estimated to reach Tehran with a delay of 6.5 hours.
On Jul 26th 2019 The Aviation Herald learned engine #3 (inboard right hand) surged enroute followed by vibrations, the engine was reduced to idle (with no vibrations anymore), the crew returned to Frankfurt. On the top of descent into Frankfurt the crew shut the #3 engine down. The engine is going to be replaced.