Canadian investigators have disclosed that an EVA Air Boeing 777-300ER crew followed an incorrect taxiway line before striking a pair of light poles.
The aircraft had been taxiing at Toronto for departure to Taipei on 2 December.
Transportation Safety Board of Canada says the aircraft had been cleared to taxi to runway 33R after de-icing, via taxiways V, E and D.
While passing through a pad on the airport's main de-icing facility, the 777 followed the southern taxi line marked '1S' rather than the central line '1C'. The two are parallel and separated by around 30m.
As a result the aircraft's right wing struck two light poles, one of which broke off at its base and fell.
The 777 (B-16718) sustained substantial damage to the leading edge of its wing and outboard slats.
No fuel leak or fire occurred and none of the 240 passengers and 22 crew members was injured.