Incident Overview
On March 10, 2014, at approximately 16:15 local time, at Gdańsk Airport (EPGD), an Embraer 170-100 aircraft was parked at gate 10 when a ground handling agent worker damaged the external power receptacle during ground servicing. The driver of a tug, who was responsible for towing the ground power unit (GPU), failed to disconnect the power cable from the aircraft before towing. He attached the GPU's tow bar to the tug and started towing, which resulted in the power plug being forcibly pulled from the receptacle, causing damage to the aircraft's external power receptacle.
Details of the Event
According to the investigation, the driver had all the necessary qualifications to operate vehicles on the apron and to handle the GPU. The incident occurred despite the existence of a procedure (ONR 2.1 section 10.7) that specified the correct sequence for GPU handling, which the driver did not follow. During the inspection of the damage, it was found that the pins in the receptacle were bent due to the forcible removal of the plug by the diesel-powered tug. Additionally, one of the locks on the panel that covers the external power receptacle (125AL) was found to be inoperative.
Cause
The cause of the incident was the lack of proper sequence of actions during the disconnection of the ground power unit (GPU).
Outcome
The aircraft was released for flight in accordance with Minimum Equipment List item 24-42-00 and maintenance procedures as per Aircraft Maintenance Manual 24-42-00-040-801-A Revision 37. No injuries or fatalities were reported. As a preventive measure, the incident was discussed with the handling agent's personnel to remind them of the correct procedures for GPU operation. No safety recommendations were issued by the investigation board.