From Transport Canada:
2007/09/17
Further Action Required: Yes
O.P.I.: Maintenance (Quebec Region)
Narrative: A07F0163: The Air Canada Airbus A340 aircraft operating as ACA007 was en route from Vancouver to Hong Kong when, in the vicinity of Anchorage, the crew experienced a zero oil quantity indication in the # 4 engine. In accordance with the QRH checklist, the crew shut down the engine. They then diverted to Anchorage, where the aircraft landed approximately 19,000 KGs overweight. Maintenance found a loose drain plug on the # 4 engine oil filter. Both drain plug seals were replaced, an overweight landing inspection was carried out, and the aircraft returned to service.