Background
The airplane was parked with the engines shut down, the parking brake set, and the wheels chocked. The captain stated that passengers remained on board while some baggage was offloaded from the aft baggage compartment to avoid overloading the landing gear struts.
Sequence of Events
The captain opened the door and exited the airplane to meet the agent. The agent approached the airplane driving a tug pulling a baggage cart. According to the captain, while the agent turned the corner to line up the baggage cart with the airplane, the cart struck and damaged the left-hand stabilon.
The agent reported driving clockwise around the airplane to position the cart for baggage unloading. He noted that he was close enough to the airplane that the top right corner of the baggage cart hit the stabilon.
Findings
The baggage cart involved was new and taller than those previously used at the airport. This was the first time the agent had operated this particular cart. No other factors were identified in the source.