What happened
On 27 September 2016, an Etihad Airways Boeing 777-3FXER, registration A6-ETL, was preparing for a commercial passenger flight from Abu Dhabi International Airport to Sydney, Australia. Shortly after rotation during takeoff, the flight crew experienced a loud bang and a sudden increase in the Exhaust Gas Temperature (EGT) of the number one engine. This was immediately followed by a 'L ENG FAILURE' alert on the Engine Indicating and Crew Alerting System (EAT), which triggered an automatic shutdown of the engine.
Despite the loss of power, the crew maintained control of the aircraft and engaged the autopilot at approximately 400 feet. The commander declared a MAYDAY and elected to return to Abu Dhabi. During the return, air traffic control informed the crew that tire debris had been discovered on the runway. The aircraft landed safely at 1203:44 LT with no injuries to the 352 people on board.
The investigation
The UAE Air Accident Investigation Sector (AAIS) examined the sequence of events, focusing on the mechanical failure and the condition of the airport environment. Investigators analyzed the damaged nose wheel tire and the engine components. The investigation looked into the maintenance history of the tires, the airport's foreign object debris (FOD) management, and the physical condition of airport ground lights.
Technical analysis of the nose wheel tire revealed that the tread had been damaged by contact with a sharp object. The investigation also noted that some aircraft stand maneuvering guidance lights had sharp edges, which could potentially damage aircraft tires.
Findings
- The primary cause of the incident was the shedding of the No.1 nose wheel tire tread after it made contact with foreign object debris (FOD).
- The resulting tire debris was subsequently ingested by the No.1 engine, leading to its failure.
- The airport lacked an automated FOD detection system for its runways and taxiways.
- The aircraft manufacturer had not previously performed a risk analysis regarding the potential for nose gear tire debris to be ingested by the engines.
- Some airport ground lights had sharp edges caused by damage from towbarless tugs during disengagement.