An Iceland Air Boeing 757-200, registration TF-ISD performing flight FI-510 from Keflavik (Iceland) to Hamburg (Germany) with 150 people on board, had just levelled off at cruise FL310 about 120nm east of Keflavik when the crew received an engine (RB211) fault indication, shut the engine down, drifted down to FL210 and returned to Keflavik for a safe landing on runway 10 about 55 minutes after departure.
The airline reported a technical problem prompted the return to Keflavik.
A replacement Boeing 757-200 registration TF-ISY reached Hamburg with a delay of about 3 hours.
The occurrence aircraft is still on the ground 12 hours after landing back.