What happened
During ground operations, an Airbus A319, registration N313NB, was being taxied by a maintenance technician from a maintenance area toward Gate 10. Upon reaching the gate vicinity, the technician engaged the parking brake and waited for ground crew and jetway operators to arrive. Once the personnel were in position, the technician released the parking brake.
As the aircraft began to move, the technician advanced the thrust levers approximately halfway out of the idle detent. The aircraft accelerated to a significant speed, at which point the technician realized the throttles had not been returned to idle. Despite attempts to apply the brakes and pull the throttles back to idle, the aircraft could not be stopped. The Airbus A319 subsequently struck a concrete support column belonging to the jetway. The collision caused the left wing of the aircraft to strike a parked Boeing 757-251, registration N550NW, located at the adjacent gate. The impact resulted in the nose gear of the Airbus shearing off and caused a large gash on the fuselage of the Boeing 757 near the R1 door.
Findings
Data retrieved from the flight data recorder indicated that roughly 10 seconds after the parking brake was disengaged, the thrust lever angles for both engines were increased to approximately 17 degrees. This increased power setting was maintained for about 8 seconds before the levers were returned to the idle position. The primary cause of the collision was the unintentional advancement of the thrust levers out of the idle position while the aircraft was taxiing.