What happened
In the early hours of 30 March 2017, a Boeing 787, registration 9V-OJA, was taxiing through Changi Airport when its left wing struck the right winglet of an Airbus A380-861, registration A6-EUB. The A380 was in the process of being pushed back from a parking bay in Terminal 1.
The incident began when an air traffic controller in training instructed the 9V-OJA to "taxi on greens" and hold short of Taxiway WA. While the controller intended to redirect the aircraft to a different taxiway (WP), the green taxiway centerline lights were still configured to lead toward WA. Following the visual guidance of the illuminated lights, the flight crew of the 78 and 0 turned onto Taxiway WA. Simultaneously, the A6-EUB was being pushed back into a position that obstructed the path. As the two aircraft passed, the wing of the 787 made contact with the winglet of the A380, causing structural damage to both aircraft, including delamination and cracked panels. No injuries were reported.
The investigation
The investigation examined the use of the aircraft taxi guidance system, which uses green centerline lights to guide aircraft at night or in low visibility. It was established that the controller did not verbalize the specific taxi route, and the lighting configuration did not match the controller's intended route. The investigation also looked into the lack of a red stop bar at the intersection and the effectiveness of existing aerodrome advisory charts.
Furthermore, investigators found that the cockpit voice recordings from the 9V-OJA were unavailable because the flight crew failed to deactivate the flight recorders after the event, allowing the data to be overwritten.
Findings
- The primary cause was the non-alignment of the green taxiway centerline lights with the controller's intended taxi route, which led the pilot to turn onto an unintended taxiway.
- The controller's plan to reconfigure the lights was not executed before the aircraft reached the intersection.
- There was insufficient clearance between aircraft taxiing on WA and aircraft being pushed back from bay C23.
- The flight crew relied on the visual guidance of the green lights without verifying the specific taxiway designators.
- Previous similar occurrences involving aircraft at the same location had not been sufficiently addressed by the safety management system.
Safety action
Following the incident, several safety measures were implemented:
- The air traffic services provider restricted pushback from bay C23 if the aircraft would end up facing south.
- The aerodrome operator suspended certain pushback operations at bay C23 until procedures were updated.
- The Civil Aviation Authority of Singapore (CAAS) recommended enhancements to the lighting system to prevent unintended routing.
- The airline operator issued notices to pilots regarding cautious taxiing and the necessity of deactivating flight recorders after significant incidents.