Incident Overview
On 6 September 2017, an Embraer ERJ-175 was executing an approach to land at EDMM (Munich Airport) when the flaps jammed at position 2 and a FLAP FAIL message appeared. The crew discontinued the approach and performed the actions prescribed by the QRH FLAP FAILURE checklist. The aircraft subsequently landed with flaps at position 2 and slats at position 3. The landing occurred without further consequences.
Post-Flight Actions
After landing, the flight crew notified the Maintenance Control Center (MCC) and technical services. The aircraft's next flight was cancelled. Lufthansa technical personnel diagnosed and rectified the fault at Munich Airport. The cause of the flap malfunction was identified as a lack of lubrication on the flap actuating components in the left wing, specifically the flap actuators and torque tubes.
Maintenance History
The operator's safety board requested an analysis of the aircraft's maintenance records, focusing on the occurrence of such faults and the date of the last flap system lubrication. It was reported that a maintenance task involving lubrication of the actuator mechanism had been assigned and confirmed as completed by the maintenance organization's mechanics on 2 September 2017. However, following correspondence between the operator and the approved maintenance organization (AMO) that rectified the fault, it was determined that no grease was present on the left wing flap mechanism, while grease was visible only on the right wing mechanism.
Probable Cause
The incident was attributed to a lack of lubrication of the left wing flap actuation system components.
Safety Recommendations
No safety recommendations were issued by the investigation board.