What happened
On the night of August 6, 2006, a Boeing 737-40 7400, registration TC-SKB, was undergoing push-back operations at Amsterdam Schiphol Airport. After completing the push-back maneuver, the tug driver disconnected the communication cord and removed the steering by-pass pin. Following a personal practice intended to ensure visibility, the tug driver remained near the aircraft to display the pin to the flight crew rather than immediately moving the tug to a safe distance.
Upon receiving taxi clearance, the flight crew applied power to the engines. The aircraft began to move forward, likely due to the slope of the apron. The tug driver, noticing the movement, attempted to signal the crew to stop, but the aircraft continued to roll. The right-hand engine of the Boeing 737-400 subsequently struck the tug. The collision resulted in damage to the engine cowling and caused the tug's headset cord to be ingested into the engine, resulting in two damaged fan blades that exceeded operational limits and two others requiring rework.