QF 72 Diverted to Learmonth

[Anthony J]

It is in Sydney and will be back in service in December.

[Philip Argy]

This media release just out from ATSB:

ATSB Preliminary Report: Qantas Airbus A330-303 In-flight Upset on 7 October 2008

13 November 2008


On Friday, 14 November 2008 at 10.00 am AEDT (local time), the ATSB will conduct a media conference to release its preliminary safety investigation report into the circumstances surrounding the in-flight upset accident of an Airbus A330-303 aircraft near Learmonth in Western Australia on 7 October 2008.
When: Friday 14 November 2008
Where: 62 Northbourne Avenue, Canberra City ACT (New ATSB Headquarters)
Time: 10.00 am AEDT (local time)

[Daniel F]

http://www.atsb.gov.au/publications/...200806143.aspx

[Philip Argy]

Actual report is at: http://www.atsb.gov.au/publications/...070_prelim.pdf

Not materially different from the initial report. More detailed investigation of the ADIRU-1 failure and its impact on other systems is about to be conducted on a multi-agency (Australian, French and USA) basis.

It seems to me that there is a logic bug or multiple logic bugs in the A330's avionics such that redundant components are not switched in, or their input is not preferred, when a fault has been detected in a primary component. The aircraft had 3 ADIRUs only one of which was determined to be faulty, yet the faulty ADIRU-1 was not thereafter ignored and the two working redundant ADIRUs were not utilised in the way that one would have expected the system to operate. Basically the physical redundancy was not utilised by the avionics logic as a consequence of which spurious data spikes continuously interfered with various components of the avionics, including aural and visual warning alarms on an ongoing basis until landing in Learmonth. These included concurrent stall and overspeed alarms and warnings, and an ECAM with a display that continued to scroll multiple warnings and information so fast that the flight crew was unable to interact with them.

This is truly a scary scenario that, no matter how low the probability of recurrence exists, requires exhaustive investigation and, in my view, a rethink of how these systems are tested before certification.

[Tom Lohdan]

Originally Posted by Philip Argy

This is truly a scary scenario that, no matter how low the probability of recurrence exists, requires exhaustive investigation and, in my view, a rethink of how these systems are tested before certification.

You forgot the mention of:

The ATSB has received many suggestions from members of the public to consider the effect of various external sources of electromagnetic interference on the aircraft, particularly any transmissions by the Harold E. Holt very low frequency transmitter near Exmouth, WA. Initial analysis suggests it is unlikely that any transmissions from this facility could affect systems on board an aircraft flying near the vicinity. However, further assessment of this possibility and other possible sources of external electromagnetic interference will be examined.

With a transmission power of 1000 kilowatts, it is the most powerful transmission station in the Southern hemisphere.

When it happened I did look into the station and researched many other boards, but everyone came back with it would not cause issues with an aircraft.

Now the ATSB has included it.

[Philip Argy]

This appeared on the ATSB website this afternoon:

Qantas Airbus A330 incident, 480km North West of Perth on 27 December 2008

02 January 2009


The Australian Transport Safety Bureau was advised on 27 December 2008 of an occurrence that day involving a Qantas Airbus A330-300 aircraft while in cruise at FL360 (36,000 ft) enroute from Perth to Singapore.
At about 0829 UTC (1729 Local Time), the autopilot disconnected and the crew received an ECAM message (NAV IR 1 Fault) indicating a problem with ADIRU Number 1. The crew actioned the Airbus Operations Engineering Bulletin (OEB) procedure by selecting the IR 1 push-button to OFF and the ADR 1 push-button to OFF. Both OFF lights illuminated. The crew elected to return to Perth and an uneventful overweight landing was conducted. At the time that the autopilot disconnected, the aircraft was approximately 260 nautical miles (NM) North-West of Perth airport and approximately 350 NM South of Learmonth airport.
It is very early in the investigation and too soon to draw any conclusions as to specific causal factors involved in this incident. As it appears to be a similar event to a previous event involving an A330 aircraft (AO-2008-070 on 7 Oct 2008) it will be included as part of the earlier investigation. The ATSB investigation will explore all aspects of the operation of the aircraft, including examination of recorded data, and any commonalities with past occurrences.
While the investigation is likely to take a number of months, the ATSB has been working with a number of national and international parties on this investigation and plans to release an Interim Factual report by about mid-February 2009.

This is now more serious than before and requires deeper investigation of what could be shaping up as Australia's own Bermuda Triangle!

[Bob C]

This appears to be the third such event as a B777 of Malaysia Airlines had problems on 1 August 2005 ; http://aviation-safety.net/database/...0801-1&lang=fr refers.

It does seem odd that two QANTAS A330s have been affected in such a short time and I wonder why other carriers are not experiencing similar problems as I presume this is happening on a major airway to Singapore.

Could there be quality control problems at Airbus, QANTAS or the manufacturer which have failed to detect faults in the nav system ? Or perhaps new equipment has been installed at the Harold E Holt Communications Station which may be under test or when operational under certain circumstances MAY be affecting the nav systems in the QF aircraft. Are these unique to QF or are the same systems installed in other aircraft ?

Whatever the causes, an investigation should be conducted immediately but I very much doubt that the USN would be too forthcoming about any
equipment at its base.

[Montague S]

perhaps our American friends can stick their spying equipment on the recently retired USN John. F Kennedy and stick it in the middle of the Indian Ocean?

[Rhys Xanthis]

Originally Posted by Montague S

perhaps our American friends can stick their spying equipment on the recently retired USN John. F Kennedy and stick it in the middle of the Indian Ocean?

Diego Garcia? Or does the US know something we don't about it's effect on aircraft

me smells a conspiracy

[Philip Argy]

This News Limited report makes the Harold Holt transmission issue seem less likely, despite the fact that to this day more mystery still surrounds the real Harold Holt's disappearance than any X-files episode:

Last week, a Royal Australian Air Force transport aircraft was forced to return to Learmonth air base after the cabin filled with fumes.

The RAAF said the C-17 Globemaster was heading for the Edinburgh base in Adelaide with a number of people on board when fuel vapours began leaking into the cabin.

The aeroplane returned to Learmonth where police said the problem had been rectified.

And for those who are taking a greater interest in the Very Low Frequency transmission base, here's some background of unvouched accuracy:
http://www.globalsecurity.org/milita...ty/exmouth.htm