The Airbus Industrie A330-303 aircraft was being operated on a scheduled passenger service between Hong Kong and Sydney. The pilot in command and second officer were seated at the aircraft control stations while the copilot was in the crew rest area.
In the course of discussions between the pilot in command and second officer, it became evident to the pilot in command that the second officer was no longer responding to conversation. Upon checking, the pilot in command found the second officer to be suffering from what he believed to be a seizure. He was removed from the operating station and replaced by the aircraft's copilot.
The second officer was removed to the crew rest area and immediately attended by a medical practitioner who was travelling on the flight. The flight continued to Sydney.