Sequence of Events
The airplane was pushed back from the gate, the tug was disconnected, and the engines were started. The pushback tug drove away to the gate. Another tug, towing a baggage cart with three pieces of late cargo, drove up to the mid cargo compartment on the right side of the airplane. The baggage tug driver and the right side wing walker began to load the cargo into the mid-section cargo compartment. One piece of cargo would not fit, so they began to carry it to the forward cargo compartment. The left side wing walker, who had been standing in front of the airplane and was considered to be the marshaller, walked to the forward cargo bin, opened the door, and began to assist in the loading.
While the loading was in progress, the airplane began taxiing. The right wing struck the tug, which had parked in front of the right wing.
Procedural Deviations
The ground marshaller did not give a wave-off to the flight crew, nor did he alert the flight crew that additional cargo was to be loaded, as required by the flight operations manual and the customer services manual. Furthermore, the flight crew did not receive nor did they give a salute to anyone, and they did not use their nose wheel taxi light to signal anyone, as stated in their flight operations manual.