Australian accidents and incidents - some worrying trends

The last time, I took for granted that a Safeskies audience would know what the ATSB was and the roles it played in Australia's system of aviation safety. Conversations with a number of you - and with others - have since convinced me that I might have been over-optimistic on that score.

We're still positioned in the public's mind as 'the accident investigator'. Certain television series only reinforce that view. Thorough and effective investigation is of course an essential part of what we do - a necessary pre-condition - but it's only one of several means and definitely not an end in itself.

The end goal is improved safety.

So, with apologies to those of you who think I'm stating the obvious, here's the simple person's picture of the system of safety and where we fit in.

Having established the particular - and in our view essential - role of the ATSB, let's move to an equally simple picture of how we carry out that role.

In terms of our priorities (if not necessarily allocation of resources), safety occurrence information is of equal weight with investigation in identifying issues and trends in the system of safety.

The Australian system is almost unique in how the no-blame investigator is the focal point of mandatory occurrence reporting, rather than the regulator. This sends a clear signal: understanding what might have gone wrong and fixing it has priority over holding people and organisations to account for their responsibilities - important though that is.

Don't get me wrong: we pass information from all the occurrence reports we receive to CASA on a daily basis and this informs their regulatory scrutiny of the system of safety. That's as it should be. My point is more that the concepts of just culture are embedded in the overall system of safety and how roles are allocated within it.

In any event, our database of occurrence information is a formidable source of safety information.
So, what is all this data telling us?

Looks like a beautiful trend in commercial air transport. But embedded in that is an average over the last ten years of two fatal accidents and six deaths, mainly in charter work - and none in high-capacity regular public transport.

And of course there is no room for complacency: there have been several high-capacity accidents and occurrences in recent Australian aviation that were closer than any of us would wish to disaster. I'll return to that point later.

Of course, we don't just do high-level analysis. We try and understand what is causing the occurrences we are told about. We classify each occurrence by type. During 2010, the top four occurrence types for air transport relating to accidents and serious incidents were aircraft separation; aircraft control; power-plant, propulsion and airframe; and a combination of terrain collisions, runway events and ground operations events.

Then there's general aviation. Again, the trends look pretty good.

But what underlies this is an average of 15 fatal accidents causing 24 deaths each year. And about half those accidents and half those deaths relate to private and business flying.

Put crudely, private pilots are dying at the same rate as motor cyclists. And they are doing it in sadly predictable ways. This is why we have put some of our resources into a series of 'avoidable accident' publications. We want to help pilots understand what can get them into potentially fatal trouble and how to reduce their risks.

I'll leave that there. So let me simply reiterate my main point. We hold the national safety occurrence dataset on behalf of the aviation sector as a whole. We are committed to meeting the responsibilities of using that information, sharing it and making it publicly available. But it's critically dependent on getting the information in the first place.

These are just some boring workload indicators of our core investigation business.

They do illustrate some important points, though. We're getting better at putting our investigative attention where it should be, at scoping our investigations and completing them more quickly without reducing quality. And we're heading towards a sustainable level of investigation activity - and some reasonable prospect of giving each significant occurrence the attention it deserves.

All this investigative work is aimed at identifying safety issues.

And for each safety issue we identify, we do a formal risk assessment, to establish whether the risk is critical, significant or minor.

The only critical safety issue we identified in the last year related to a certain A380 aircraft. The aircraft's No 2 engine had sustained an uncontained failure of its intermediate pressure turbine disc. Sections of the disc had penetrated the left wing and the left wing-to-fuselage fairing, resulting in structural and systems damage to the aircraft.

Within a month of the accident, the ATSB, leading an investigation that involved a range of other countries and major corporations, had established the presence of fatigue cracking within a small stub pipe that feeds oil into one of the engine's bearing structures.

The fatigue was attributed to misaligned counter-boring of the stub pipe as part of the engine manufacturing process. Such fatigue cracking, if it occurred in other engines, had the potential to create oil leakage which could lead to catastrophic engine failure from a resulting oil fire.

As a result of this work, a number of safety actions were immediately undertaken by Qantas, the Australian Civil Aviation Safety Authority, Airbus, Rolls-Royce plc, and the European Aviation Safety Agency that enabled the resumption of safe flight by all aircraft equipped with the failed engine type.

The investigation continues so that all the safety implications and lessons from the accident, including positive lessons about how the emergency was handled, can be reviewed and published.

But we also identified a number of significant safety issues in other investigations.

One significant investigation (AO-2008-003) was an occurrence involving a Boeing 747-438 aircraft which was subject to a number of electrical power-related malfunctions affecting many of the aircraft's communication, navigation, monitoring and flight guidance systems.

While the consequences were potentially very serious, the aircraft's engines and hydraulic and pneumatic systems were largely unaffected and the aircraft landed safely at Bangkok.

The malfunctions were found to have been caused by leaks resulting from an overflowing galley drain.

The investigation identified a number of serious and systemic safety issues regarding the protection of aircraft systems from liquids. In response, the aircraft manufacturer and operator implemented a number of safety actions intended to prevent a recurrence. In addition, the United States Federal Aviation Administration issued a notice of proposed rulemaking to adopt a new airworthiness directive for certain 747-400 and 747-400D series aircraft to install improved water protection. The ATSB issued two safety recommendations and one safety advisory notice as a result of the investigation.

While we issued recommendations, the key point here is that there is no single party that is able or can be held to account for fixing a set of issues that start with design and certification, move through operator-specific configuration decisions to maintenance procedures and their oversight and extend to flight training and procedures.

The no-blame investigator can specify the problem, but we need to find better ways of getting all the relevant parties alerted to the issue and active in resolving it. We've got to get beyond recommendations to communicating safety issues in a compelling way.

Another investigation, AO-2009-065, highlighted potential problems with unreliable airspeed indications in Airbus A330 and A340 aircraft. When airspeed data is unreliable, some aircraft systems respond in ways that pilots do not encounter often. Airspeed data is derived from mechanisms called pitot probes, which respond to variations in the airflow outside an aircraft.

In the occurrence the ATSB investigated, involving an Airbus A330-202 aircraft, there was a brief period of disagreement between the aircraft's three sources of airspeed information. The autopilot, autothrust and flight directors disconnected and the flight control system reverted to alternate law, which meant that some flight envelope protections were no longer available. There was no effect on the aircraft's flight path, and the flight crew followed the operator's documented procedures. The airspeed disagreement was due to a temporary obstruction of the captain's and standby pitot probes, probably due to ice crystals. A similar event occurred on the same aircraft on 15 March 2009.

Both of the events occurred in environmental conditions outside those specified in the certification requirements for the pitot probes. That is, the certification requirements were not sufficient to prevent the probes from being obstructed with ice during some types of environmental conditions. As a result of its own investigations of similar occurrences, the French Bureau d'Enquêtes et d'Analyses pour la sécurité de l'aviation civile (BEA) has recommended the European Aviation Safety Agency (EASA) to review the certification criteria for pitot probes in icing environments. The ATSB is satisfied that this work, when complete, will address this significant safety issue.

Other investigations also identified significant safety issues relating to the safety of air transport.

These related to the supervision of agricultural pilots, training and supervision of charter pilots, potentially hazardous helicopter winching procedures, turbulence caused by buildings at airports, airspace design and management and problems with the management by air traffic control of compromised separation of aircraft. In each case, the ATSB was satisfied that action had been taken or was in train to address the identified safety issues.

I referred earlier to the increased number of short investigations that complement larger investigations by providing more detailed data on a significant number of safety occurrences for future research and analysis. We produced three bulletins containing a total of 52 short summary reports in the course of last year. Examining these in conjunction with our research reports and our larger investigations draws out some potentially significant safety trends in Australian aviation.

The first is the continuing prevalence of incidents and some accidents involving inadequate execution by pilots of 'see-and-avoid' procedures in the vicinity of smaller airports. The ATSB has consistently drawn attention to the limitations of see-and-avoid, but work remains to be done in making sure pilots understand and respond to this.

The second is a range of occurrences which involve issues with the training, checking and supervision of pilots. This trend is independent of the total hours of flight experience pilots have and often involves the execution of normal but rarely used procedures. The ATSB will continue to monitor this area to see if the underlying issue can be drawn out more clearly.

Third is the number of occurrences involving the breakdown of air traffic control separation of aircraft or problems in recovery of a compromised separation. Airservices Australia has taken safety action to deal with recovery from compromised separation (see investigation report AO-2009-080), but several investigations currently under way are likely to clarify whether a series of separation breakdowns point to any systemic safety issue.

Finally, there are a number of safety occurrences in general aviation which point to a continuing exposure to known risks: a sequence of collisions with previously identified powerlines; poor management of fuel leading to fuel exhaustion; and pilots flying visually into instrument conditions. As I indicated earlier, the ATSB has dealt with the continuing prevalence of these types of occurrence by the production of focussed educational material for pilots and by conducting safety education programs based on this material.

Some parting thoughts. A number of our investigations have shown that Australian pilots have responded effectively and with safe outcomes to circumstances where automated aircraft systems acted anomalously. Without wishing to sound complacent or to draw comparisons, these safe outcomes from potentially catastrophic events provide a number of positive lessons for the future.

There has been much discussion about over-reliance on aircraft automation and the de-skilling of pilots. There is a great need for us to change the terms of that debate.

Large, complex and highly automated aircraft are here to stay. We need to turn our focus to ensuring that flight crews are prepared for that environment - and for the circumstances where automation fails or reacts unpredictably. We are not just talking about flying skills. We need to understand how best to prepare for the rare, unpredictable, stressful and complex event.

A key focus of the ATSB's work is and remains the learning and promulgation of positive lessons. Things often go very well - and it is crucial to understand why. We look forward to working with you not only to discover why things go wrong, but also to recognise why they didn't and make sure that others share in the benefits of that learning.

The Australian Transport Safety Bureau will conduct an independent systemic investigation into operations on the interstate rail line between Sydney and Melbourne in response to a request from the Minister for Infrastructure and Transport, the Hon Anthony Albanese MP.

The systemic investigation follows a number of specific incidents on the rail line, which is leased and operated by the Australian Rail Track Corporation (ARTC).

As part of the systemic investigation, the ATSB will look at all relevant matters including:

• The operational condition of the interstate rail track and measures being put in place to maintain the safety of rail operations where track quality is below acceptable operational standards;
• Actions undertaken by the ARTC to remediate the track and address the safety of operations;
• Safeworking practices in relation to the track; and,
• A systemic review of safety systems, including signalling and the quality assurance of work undertaken on the track.

The lessons from tragic accidents following flight into cloud or poor visibility are often ignored or forgotten, according to the ATSB. Some pilots who are only qualified to fly when visibility is good (visual flight) remain exposed to significant risk of a fatal accident.

To fly in cloudy or foggy conditions, pilots need an instrument flight rules rating. A booklet released by the ATSB today highlights the dangers of pilots without an instrument rating flying into bad weather.

With 14 fatalities in the past five years, general aviation accidents involving visual flights entering cloud remain a significant concern in aviation safety.

ATSB General Manager Strategic Capability, Mr Julian Walsh, said these accidents were all the more tragic because they were avoidable.

'We want to encourage pilots, no matter what their experience level, to develop the knowledge and skills to avoid unintentionally flying into bad weather.'

'Weather does not always act as the forecast predicts. If the weather starts to deteriorate, unqualified pilots should make an early decision to turn back or divert before they are caught in cloud,' Mr Walsh said.

'Before they take-off pilots need to carefully plan their flights and get up-to-date weather forecasts. If there's any doubt, don't fly.'

The report, the latest in the ATSB's 'Avoidable Accidents' series, presents case studies on the dangers of flying visual flight rules in deteriorating weather. It focuses on the key safety lessons learnt from each of these cases.

The booklet describes strategies for pilots to avoid the dangers of flying into adverse weather conditions, including:

• pre-flight planning
• considering alternate plans in case of an unexpected change in the weather
• making timely decisions to turn back or divert
• using a 'personal minimums' checklist to help control and manage flight risks, including marginal weather conditions.

Accidents involving Visual Flight Rules pilots in Instrument Meteorological Conditions

The latest news on transport safety investigations is now available from the Australian Transport Safety Bureau's Twitter account: @ATSBinfo(Opens in a new tab/window)

ATSB will use Twitter to provide information on transport safety activities and initiatives such as:

• new safety investigations
• investigation updates
• investigation and research report releases
• new safety awareness products.

Follow the ATSB on Twitter at @ATSBinfo(Opens in a new tab/window)

More information is available from the ATSB website www.atsb.gov.au

Pilots of single-engine aircraft are at greater risk of having an accident following a partial engine power loss than they are of a full engine failure, according to the ATSB.

A partial engine power-loss occurs when the engine provides less power than that commanded by the pilot.

ATSB General Manager Strategic Capability, Mr Julian Walsh, says partial power loss is actually a more complex situation than a complete failure, and it can be much harder to manage.

"The pilot is in a situation where the engine is still providing some power, but it may be unreliable, and the available power level might be difficult to assess," Mr Walsh says.

"As a result, pilots are uncertain about their aircraft's capabilities, and what their options are - a situation that can turn into disaster very easily."

"The good news is that through a range of strategies, presented in the ATSB's latest publication, pilots can avoid these accidents."

These are:

• Form a plan before flight of what you will do if faced with a partial power loss
• Conduct thorough pre-flight checks
• Following any power loss, take positive action and maintain control of the aircraft.
  Up until now, partial power losses have been a largely unexplored topic in aviation. This is despite partial power loss events occurring three times more frequently than complete engine failures during take-off and initial climb.

From 2000 to 2010, there were 242 accidents reported to the ATSB involving single-engine aircraft sustaining a partial engine power loss after take-off. Nine of these were fatal, mostly involving pilots losing control of the aircraft after an aerodynamic stall. This is in contrast to only 75 accidents (none of which were fatal) occurring after a full engine failure after take-off.

The ATSB booklet Managing partial power loss after take-off in single-engine aircraft, is the latest publication in the ATSB's 'Avoidable Accidents' series.

Robinson R22 helicopter pilots are being cautioned of a drive belt risk following a fatal accident in north-west Queensland.

On 9 May 2011, a Robinson R22 Beta II helicopter crashed after its drive belts failed during mustering operations near Julia Creek (the drive belts transmit engine power to the helicopter's main and tail rotor blades). The pilot, who died in the accident, was the only person on board.

The ATSB preliminary investigation report, released today, highlights a number of factors that can cause drive belt failure. These include excessive wear due to the misalignment of the belt drive sheaves, and operating the helicopter beyond the manufacturer's recommended limits.

ATSB Chief Commissioner, Mr Martin Dolan, said the accident is a grim reminder of the dangers facing pilots who conduct mustering-type flights.

'Pushing these helicopters to and beyond their normal limits can lead to excessive wear and potentially disastrous consequences,' Mr Dolan said.

'The ATSB is urging Robinson R22 helicopter operators and maintainers to regularly and carefully check their R22 helicopter drive system for misalignment, abnormal wear or other indications of drive belt damage.

'Operators who find anything unusual with their R22 drive systems are asked to contact the ATSB on 1800 020 616.'

The investigation is continuing. The ATSB will release a final investigation report within 12 months.

More information on this investigation AO-2011-060 is available at the ATSB website.

The Civil Aviation Safety Authority has also previously released an Airworthiness bulletin(Opens in a new tab/window) on the Robinson R22 main rotor drive system, which can be found on the (Opens in a new tab/window)CASA website, www.casa.gov.au(Opens in a new tab/window).

The ATSB's successful retrieval of flight data from a badly damaged aircraft has been described as a 'breakthrough' by Royal New Zealand Air Force authorities.

On 14 January 2010, the Royal New Zealand Air Force Red Checkers CT-4 Airtrainer aircraft crashed at Ohakea Air Force Base in New Zealand while practising for an upcoming aerobatics display. The pilot died in the accident and the aircraft was destroyed by fire.

The ATSB transport safety report, released today, details the efforts taken to retrieve a large amount of data from the aircraft's badly damaged flight data recorder following a request of assistance from the Royal New Zealand Air Force. The data recorder was fitted to the aircraft to gather performance data as part of a fatigue monitoring program.

ATSB Chief Commissioner, Mr Martin Dolan, said the report reflects the ATSB's strong spirit of international cooperation to improve safety.

'While the flight data recorder was severely damaged by fire, ATSB investigators succeeded in retrieving important flight data through meticulous, painstaking and imaginative work,' Mr Dolan said.

'We then passed this data onto Royal New Zealand Air Force investigators who found it invaluable to their investigation.'

'This investigation highlights the ATSB's world-class technical expertise in transport safety investigations.'

A copy of the ATSB transport safety report AE-2010-024 is available via the ATSB website.

An ATSB investigation into a fatal helicopter accident has highlighted the continuing risks facing pilots when flying around powerlines.

On 20 May 2010, a helicopter struck a powerline during forestry spraying operations near the Latrobe Valley Airport in Victoria. The helicopter crashed and the pilot, the only person on board, died.

The ATSB's investigation report, released today, describes how the pilot struck the wire on the final spray run despite being aware of the wire's location.

ATSB Chief Commissioner, Mr Martin Dolan, said this accident is part of a worrying trend in aviation accidents.

"Tragically, pilots continue to die in wirestrike accidents," Mr Dolan said.

"More than 180 wirestrike accidents have been reported to the ATSB over the past 10 years.

"Pilots must always be alert to the risks of flying near wires. Using basic strategies to manage these risks, such as using temporary powerline markers as advised in this report can save pilots' lives."

The ATSB and the Aerial Agriculture Association of Australia recently released an educational booklet on avoiding wirestrikes. The booklet describes recent wirestrike accidents that occurred during spraying activities. More importantly, it provides ways for pilots to minimise the risk of striking a powerline while conducting aerial operations.

Avoidable Accidents booklet: Wirestrikes involving known wires: A manageable aerial agriculture hazard is available on the ATSB website.

Investigation Report: AO-2010-033

Agricultural pilots are being reminded of the dangers associated with flying near wires following the release of an ATSB booklet today.

The booklet, released in association with the Aerial Agriculture Association of Australia, highlights recent wirestrike accidents that occurred while pilots were conducting spraying activities.

Importantly, the report provides ways for pilots to minimise the risk of striking a powerline while conducting aerial operations.

ATSB Manager of Research Investigations, Dr Stuart Godley, said that in the majority of wirestrike accidents the pilots had known of the powerlines before they struck them.

'Typically, pilots have been working around the same wires in the hours before a wirestrike accident,' Dr Godley says.

'Due to a change of spraying plans or a clean-up run once a paddock has been sprayed, the pilot's focus is temporarily shifted away from the task of identifying the location of wires.'

The booklet provides methods for pilots to minimise the risk of striking wires while conducting aerial operations. These are:

• setting client expectations so that they are clear that safety comes first
• conducting an aerial reconnaissance before spraying and extra aerial reconnaissance before the cleanup run
• reassessing the risks when plans change
• avoiding unnecessary distractions and refocussing when distracted
• keeping vigilance limitations in mind
• actively looking for wire
• managing operational pressures including not accepting tasks that are beyond your personal minimums
• having a systematic approach to safely managing wires.

The report also highlights the role of landholders and utility owners in contributing to safety. This includes installing markers on wires, particularly where regular low-level flying takes place.

The booklet Wirestrikes involving known wires: A manageable aerial agriculture hazard is available on the ATSB website.

An interim ATSB investigation report has confirmed the sequence of events that led to the 4 November 2010 uncontained engine failure on board a Qantas A380 aircraft over Batam Island, Indonesia.

The report also sets out how, as a result of the investigation to date, Rolls-Royce, affected airlines and safety regulators have taken action to ensure the continued safe operation of A380 aircraft.

Released today, the report highlights how the intermediate pressure turbine disc in the aircraft's No. 2 engine had been weakened by an oil fire. As a result, the disc separated from its shaft, increased its rotation speed and broke into several parts. Sections of the fractured disc and other engine components penetrated the aircraft's left wing and a number of other areas on the aircraft, resulting in significant structural and systems damage.

The oil fire that weakened the disc was due to a manufacturing defect in an oil feed pipe. That defect resulted in fatigue cracking in the pipe, so that oil sprayed into an engine cavity where it ignited because of the high air temperature.

The report also shows how some of the extensive flight data recovered in the first stage of the investigation has been used to program a simulation of how the aircraft handled following the accident. This has helped investigators to understand better the aircraft's handling and performance.

The simulation was part of a broader exercise to understand the extent and consequences of the airframe and systems damage to the aircraft and the consequences for flight crew workload. The findings from this continuing work will provide valuable safety lessons for future operations.

The ATSB will continue to work with international safety agencies and other organisations to gather and compile the large amount of complex factual information required to complete the investigation. Included in this work will be:

• testing and analysing the black-coloured soot residue found in the left wing fuel tank
• analysing the flight simulation test data
• continuing to review the quality control and quality assurance system affecting the engine design and manufacturing process
• reviewing the aircraft's maintenance, including engine workshop visits.

The aircraft is currently in Singapore awaiting repair.

Given the highly complex nature of this investigation, the final ATSB report is expected to be released in May 2012.

A copy of the interim factual report is available at AO-2010-089