Incident Overview
On 10 January 2008, an Airbus A380-800, registration 9V-SKA, was scheduled for a passenger flight to Sydney. The aircraft was parked at Bay A4 of the new Terminal 3, which had commenced operation the day before. At 8:46 p.m., the aircraft was pushed back by a Schopf air tug onto Taxiway WA. During the pushback, the right hand wing landing gear and part of the right hand body landing gear left the paved taxiway. The right wing landing gear rolled over a concrete airfield lighting transformer box and onto the grass verge. The aircraft tilted slightly to the right.
Damage and Separation
The driver tried to pull the aircraft out of the unpaved ground. During the pulling, the fuse pins attaching the towing pin to the towing fitting on the nose landing gear sheared. The towing pin and tow bar detached from the nose landing gear, separating the aircraft from the air tug. The aircraft was otherwise not damaged. The detached towing pin was held in the tow bar clamp and was found rotated 180° from its original orientation; it could not be determined when this rotation occurred.
Pushback Team
The pushback team consisted of an air tug driver, a headset man (the team leader and a licensed aircraft engineer), a left wing walker, a right wing walker, and a tail walker.
Air Tug Driver's Account
The driver stated it was his first pushback of an A380 and first from Bay A4. He was concerned about the aircraft's weight and slopes, and felt the maneuvering space was tight. To ensure the aircraft cleared obstacles (the aerobridges of Bay A4 and a B777 parked in Bay A3), he pushed beyond the red apron safety line. He could not see the taxiway centerline due to the up slope and poor illumination, as the green taxiway centreline lights were not switched on. He focused on monitoring the nose landing gear steering angle to avoid exceeding limits and did not maintain the body gears close to the yellow lead-in line. He did not realize the aircraft had left the taxiway until after it happened.
Headset Man's Account
The headset man noted the aircraft was off the yellow lead-in line and alerted the driver. He did not see the driver correct the path but deferred to his judgment because the driver's supervisors had assured him the driver could safely perform the pushback. He focused on ensuring the nose gear steering angle limits were not exceeded. He saw the right wing gear approaching the taxiway edge and called for a stop, but the driver continued (the driver reported not hearing the call). After the air tug stopped, the headset man was uncertain if the aircraft had left the taxiway. The area was not illuminated, and he considered Bay A4 a difficult bay for pushbacks to the south.
Wing Walkers' Accounts
After the aircraft cleared obstacles on the left, the tail walker and right wing walker retrieved chocks and drove to the end of the pushback path. The left wing walker stood on the air tug and reported no anomalies during the pushback.