CIRCUMSTANCES: "The aircraft was planned to conduct a regular freight service to Brisbane and Cairns. After an evidently normal take-off from Runway 16 the crew contacted DEPARTUREs Radar, advised that the aircraft was climbing to Flight Level 370 and requested the direct track to Brisbane. Approximately two minutes later the crew did not respond to calls from the radar controller, and the aircraft faded from the radar screen. Witnesses subsequently reported that the aircraft was seen diving steeply towards the water. The evidence obtained from eye witnesses, recorded radar information and the Flight Data Recorder indicated that the aircraft entered a rapid turn to the right and rolled, probably to a nose-down inverted position, before entering a steep descent. The pilot in command intended to use the flight to assess the performance of the co-pilot, who was being considered for up-grading to command status. He was known to simulate emergency instrument flight conditions while checking company pilots. These simulations took the form of failures to the Flight Attitude Indicators on the left instrument panel, and the masking of the indicator on the right by covering or the removal of instrument lighting. It was likely that on this occasion that the simulated failures referred to above were given shortly before the aircraft commenced a planned turn to the left to take up the track towards Brisbane at a height of about 5000 feet. At this time the pilot in command had no external reference by which to monitor the attitude of the aircraft in relation to the horizon. The pilots did not recover control of the aircraft before impact with the water. NOTE A full report on this accident has been prepared and is available from the Australian Government Publishing Service in each Capital city."