Viscount, VH-RMI, near Winton, Queensland, 22 September 1966

Summary of principal conclusions

1. At approximately 1303 hours Eastern Standard Time on 22^nd September 1966 Viscount 832 Type aircraft VH-RMI operated by Ansett Transport Industries (Operations) Pty. Ltd. (trading as Ansett-A.N.A.) experienced a structural failure in flight and struck the ground about 13½ miles on a bearing of 260° magnetic from Winton Aerodrome in the State of Queensland.

2. The aircraft was totally destroyed.

3. At the time of the accident the aircraft was engaged on a regular public transport service from Mt. Isa to Brisbane via Longreach. The service was authorised by an Airline Licence issued to the operator and the flight was designated as Flight 149.

4. The aircraft carried a crew of four and twenty passengers, all of whom were lost as a result of the accident.

5. At the time of the accident the aircraft was proceeding to make an emergency landing at Winton Aerodrome following an emergency descent en route.

6. The forecast weather conditions and the weather conditions actually existing at the time of the flight were not such as to suggest any unusual or hazardous circumstances and had no bearing on the accident.

7. The aircraft departed from Mt. Isa at 1208 hours Eastern Standard Time.

8. The aircraft was loaded within permissible limits and there is no evidence to suggest that anything relating to the load contributed to the accident.

9. After leaving Mt. Isa the aircraft climbed to its cruising height of approximately 17,500 feet and proceeded at that level with the automatic pilot engaged until about 1247 hours.

10. At about 1247 hours the automatic pilot was disengaged prematurely and this was followed shortly after by a descent described in a message from the aircraft as an emergency descent.

11. Messages from the aircraft show that the emergency was indicated by a fire warning being received in the flight compartment.

12. At 1257 hours the crew reported they had a visible fire in No. 2 engine and that they were tracking to Winton.

13. Appropriate action was taken to prepare the aircraft and passengers for an emergency landing.

14. The crew, both pilots and hostesses, were adequately and properly trained and competent to operate VH-RMI on the 22nd September, 1966.

15. Both pilots held appropriate licences and ratings pertinent to the flight and had met the required medical standards.

16. There is no evidence to suggest that on the day of the flight the pilots were not medically fit to undertake their respective duties.

17. The flight plan was correctly and properly prepared and the quantity of fuel carried was more than adequate for the flight.

18. There is no evidence that the flight crew was aware of any unserviceability of the aircraft or any of its components prior to take-off.

19. The evidence supports a conclusion that [the Captain's] decision to divert to Winton rather than continue the flight to Longreach was an appropriate one and that he acted properly in following this course rather than electing to make a forced landing.

20. The crash of the aircraft followed the failure in an upward direction of the port wing between No. 1 and No. 2 engines at approximately 1302½ hours Eastern Standard Time when the aircraft was at a height of 3,500 feet to 4,000 feet above ground level.

21. The port wing failed as a result of a weakening of the main spar due to a fire in No. 2 cell of No. 2 fuel tank.

22. The fire originated in the No. 2 cabin blower and travelled through the rear of No. 2 engine nacelle and port wheel bay to the fuel tank.

23. The fire in No. 2 cabin blower was initiated as a result of a rotor break-up, the blower subsequently being driven in an out-of-balance condition by the quill shaft long enough for the metering unit to become separated from the rear end cover by the resulting vibration.

24. The metering unit continued to be driven after separation and lubricating oil continued to be supplied. The driven rotor lost its rear stub shaft location and caused metal-to-metal contact which generated a temperature sufficiently high to ignite the oil in that area.

25. It is not possible on the evidence to determine what was the cause of the rotor break-up.

26. The rotor break-up was not due to incorrect assembly of the extractor seal shell and the ball bearing and its housing at the last overhaul by Ansett-A.N.A ..