Over the 6-year study period between 2009 and 2014, 322 engine failures or malfunctions involving light aircraft were reported to the ATSB and/or Recreational Aviation Australia (RA-Aus).

Through routine trend monitoring of safety occurrence reporting, the ATSB became aware of a potential issue surrounding the frequency of light aircraft engine failures and malfunctions (both Australian VH and recreationally-registered). To formally and more fully examine the contributing factors behind these statistical observations, the ATSB initiated this Aviation Research investigation (under the provisions of the Transport Safety Investigation Act 2003).

Over the 6-year study period between 2009 and 2014, 322 engine failures or malfunctions involving light aircraft were reported to the Australian Transport Safety Bureau (ATSB) and/or Recreational Aviation Australia (RA-Aus). These reports involved single-engine piston aeroplanes up to 800 kg maximum take-off weight. Aircraft powered by Jabiru engines were involved in the most engine failures or malfunctions with 130 reported over the 6 years. This represents about one in ten aircraft powered by Jabiru engines in the study set having reported an engine failure or malfunction. Reports from Rotax powered aircraft were the next most common with 87 (one in 36), followed by aircraft with Lycoming (58 – one in 35) and Continental (28 – one in 35) engines. When factoring in the hours flown for each of these engine manufacturers, aircraft with Jabiru engines had more than double the rate of engine failure or malfunction than any other of the manufacturers in the study set with 3.21 failures per 10,000 hours flown.

Unlike the engines of other engine manufacturers in this study, nearly half of the Jabiru engine failures or malfunctions related to a fractured component. Engine through-bolt failures were the most commonly reported failure mechanism in Jabiru powered aircraft with 21 through-bolt fractures reported between 2009 and 2014. Taking into account the number of aircraft registered in the study period, through-bolt failures occurred in about one in 55 Jabiru powered aircraft. Although originally designed to be replaced after 1,000 hours, 19 through-bolts failed before the 1,000 hour mark, with seven failing before 500 hours. At least four failures involved engines with upgraded 3/8 inch diameter through-bolt nuts. There were no failures reported involving the newer 7/16 inch diameter through-bolts which are used in currently manufactured engines (present in about 20 per cent of Jabiru engines).

Jabiru Aircraft Pty Ltd have designed and tested a modified 3/8 inch diameter through-bolt which incorporates aspects to alleviate the effects of thermal expansion and damp resonant vibrations.

The ATSB has issued recommendations to Jabiru Aircraft Pty Ltd and the Civil Aviation Safety Authority to reduce the risk of engine failure or malfunction in aircraft fitted with Jabiru engines and to assure future reliability of these engines.

Safety message

Owners and operators of light aircraft with Jabiru engines that have 3/8 inch diameter through-bolt configurations need to be aware of the continued elevated risk of a through-bolt failure leading to an engine failure or malfunction in flight. It appears that Jabiru engine service bulletins, requiring upgraded through-bolts of the same thickness and upgraded nuts to the 12-side ARP nuts, may not have fully addressed this issue. Thicker 7/16 inch through-bolts (installed in newly manufactured engines and recommended as a retro-fit for aircraft conducting flight training), appear to have improved the reliability of Jabiru engines, although future monitoring will provide more definite evidence.

Read the ATSB research report AR-2013-107

Gastrointestinal illness, followed by laser strikes are the leading causes of pilot incapacitation, according to a new ATSB research report.

Gastrointestinal illness, followed by laser strikes are the leading causes of pilot incapacitation, according to a new ATSB research report.

This report provides insight into pilot incapacitation occurrences in both high and low-capacity air transport, and general aviation.

In the past five years there were 23 pilot incapacitation occurrences reported per year on average. Around 75 per cent of the incapacitation occurrences happened in high-capacity air transport operations (about 1 in every 34,000 flights), with the main cause being gastrointestinal illness, followed by laser strikes. (A high-capacity aircraft provides more than 38 passenger seats and a maximum payload greater than 4,200 kg.)

Low-capacity air transport and general aviation had fewer occurrences with a wider variation of causes of incapacitation. These ranged from environmental causes, such as hypoxia, to medical conditions, such as heart attack.

Pilot incapacitation can result in a restriction of flight duties in high-capacity operations but with multi - pilot crews these occurrences usually had minimal effect on the flight.

In single pilot operations there could be more serious consequences such as collision with terrain.

The report also recommends effective ways to manage pilot incapacitation, across all levels of aircraft operations.

Safety message

Pilot incapacitation can occur in any operation type, albeit rarely.

In high-capacity air transport operations, the practice of ensuring all pilots on the same flight eat different meals prior to and during the flight has been an effective defence preventing all pilots on the same flight becoming incapacitated at the same time.

Providing pilots with training in dealing with incapacitation events has been effective for when these events do occur. Pilots are also encouraged to report laser strikes to police and the Office of Transport Security.

In low-capacity air transport operations, providing emergency training to non-flight crew, such as aeromedical nurses, is an important defence in case of pilot incapacitation.

Finally, in general aviation, pilots are reminded to assess their fitness prior to flight. Assessment of fitness includes being aware of any illness or external pressures they may be experiencing.

Read the research report AR-2015-096 Pilot incapacitation occurrences 2010–2014

The ATSB has released its latest Bulletin of short investigations covering incidents involving jet, turboprob and piston aircraft and helicopters.

• Issue 46 of the Bulletin features 10 safety investigations.

The ATSB has released its latest Bulletin of short investigations covering incidents involving jet, turboprop and piston aircraft and helicopters.

The Bulletin also highlights important safety messages for the broader aviation community, drawing on earlier ATSB investigations and research.

Released periodically, the Bulletin provides a summary of the less-complex factual investigation reports conducted by the ATSB. The results, based on information supplied by organisations or individuals involved in the occurrence, detail the facts behind the event, as well as any safety actions undertaken. The Bulletin also highlights important Safety Messages for the broader aviation community, drawing on earlier ATSB investigations and research.

Issue 46 of the Bulletin features ten safety investigations:

Jet aircraft

• Pre-flight planning event involving a Boeing 737, VH-YIU

Turboprop aircraft

• Weather related event involving a Bombardier DHC-8, VH-XFQ

Piston aircraft

• Collision with terrain involving a Beech A36, VH-PAK
• Fuel exhaustion event involving a Cessna 182, VH-DNZ
• Fuel management issue, involving a PA-31-350, VH-HJH
• Wheels-up landing involving a Cessna 172RG, VH-HTP
• Flight path infringement involving a Cessna 172M, VH-EJM and a vehicle
• Partial engine failure involving a Gippsland Aeronautics GA-8, VH-FGN
• Aircraft control issue involving a Liberty XL-2, VH-CZS

Helicopters

• Collision with terrain involving a Robinson R22, VH-NCL

Follow this link to: Aviation Short Investigation Bulletin Issue 46

The ATSB has released its latest Bulletin of short investigations covering incidents involving jet, turboprob and piston aircraft, helicopters and remotely piloted aircraft systems.

• Issue 45 of the Bulletin features 10 safety investigations.

The ATSB has released its latest Bulletin of short investigations covering incidents involving jet, turboprob and piston aircraft, helicopters and remotely piloted aircraft systems.

The Bulletin also highlights important safety messages for the broader aviation community, drawing on earlier ATSB investigations and research.

Released periodically, the Bulletin provides a summary of the less-complex factual investigation reports conducted by the ATSB. The results, based on information supplied by organisations or individuals involved in the occurrence, detail the facts behind the event, as well as any safety actions undertaken or identified.

Issue 45 of the Bulletin features 10 safety investigations:

Jet aircraft

• Stickshaker activation involving a Boeing 717 200, VH-NXM
• Loading event involving an Airbus A330, VH-QPJ

Turboprop aircraft

• Collisions with kangaroos involving a Fairchild SA227 (Metroliner), VH- HPE, and a King Air B200, VH-FDB

Piston aircraft

• Near collision between an Extra 300L, VH-KCF and a Robinson 44, VH-OLG
• Near collision involving a Cessna 172, VH-EOT, and a Jabiru J120, 24 5340
• Collision with terrain involving a Cirrus SR22, VH-OPX
• Partial power loss and forced landing involving a Cessna 172, VH-FPZ

Helicopters

• Near collision involving a Schweizer 269, VH-JXO, and a Military Lockheed AP-3C
• Loss of control involving a Robinson R44 helicopter, VH-ZWA

Remotely piloted aircraft systems

• In-flight break-up involving a DJI S900 remotely piloted aircraft

Follow this link to: Aviation Short Investigation Bulletin - Issue 45

The Australian Defence Science and Technology (DST) Group conducted a comprehensive analysis of the available data.

Update: 10 December 2015

The ATSB has issued an update to clarify its recently released report MH370 - Definition of Underwater Search Area.

The update establishes that the ‘power loss’ mentioned on page 9 occurring between 17:07:48 and 18:03:41 was referring to the Satellite Data Unit (SDU) only.  The SDU did not respond to an automatic interrogation from the Ground Earth System (GES) at 18:03:41 UTC, although it resumed working at 18:25:27.

Report released: 3 December 2015

This report provides an update to the MH370 search area definition, described in previous ATSB reports. For background information, please see the ATSB publications MH370 - Definition of underwater search areas, 18 August 2014 and Flight Path Analysis Update, 8 October 2014 under the tabs on this web page.

Analysis of available data has been ongoing since the search for MH370 commenced. Initial results assisted the search and rescue mission, and later refinements have formed the basis for the underwater search areas.

The Australian Defence Science and Technology (DST) Group conducted a comprehensive analysis of the available data. The analysis used models of the Inmarsat satellite communications (SATCOM) data and a model of aircraft dynamics. Recorded meteorological data (wind and air temperature) were also modelled in the analysis. The SATCOM model was calibrated using SATCOM data and flight data from B777 flights including previous flights of the accident aircraft.

Validation experiments were conducted to ensure that predictions aligned with actual flight data. The output of the DST Group analysis was a probability density function (PDF) defining the probable location of the aircraft’s crossing of the 6th arc. These results were then extrapolated to the 7th arc. The analysis indicated that the majority of solutions only contained one significant turn after the last recorded radar data. DST Group have written a book called 

detailing the entire analysis.

Performance analysis by Boeing produced a series of achievable ranges, with time intervals, for different cruise altitudes. It was noted that maintaining a constant altitude of FL350 or higher gave range values that closely matched the region on the arc corresponding to the DST Group analysis results. The DST Group and Boeing results were obtained independently and it is significant that they were in general agreement.

In contrast to the series of data points that were recorded from the SATCOM system, only the following indirect information was available to assist the ATSB in determining the end-of-flight scenario and therefore determine a search area width:

• probable aircraft systems status
• simulator results
• review of previous accidents
• glide distance.

The original ATSB underwater search area definition report published in August 2014 identified a width of 20 NM behind the arc and 30 NM forward of the arc as the priority search area width. This primary priority width has been adjusted to make it symmetrical about the arc (20 NM on both sides). The ATSB has also defined and prioritised additional search area widths.

The probability distribution of the location of the aircraft is shown in Figure 1.

Figure 1: Probability distribution of the location of MH370

Ongoing work:

Any further evidence that becomes available, and may be relevant to refining the search area,will be considered.

• MH370 - Definition of Underwater Search Area
• Bayesian methods in the search for MH370 (8.76 MB)

  by Defence Science and Technology Group, Australia. This analysis has informed the ATSB’s latest report, MH370 – Definition of Underwater Search Area.

• Read more about MH370

The Zig Zag railway has faced a number of hurdles over the past 4 years, with regulatory issues, bush fires and floods.

On 2 December the ATSB held a workshop at this well-known tourist attraction in the Blue Mountains of NSW, at the request of the ZZR board.

This workshop, presented by two senior rail investigators covered how the ATSB conducts investigations and how Australian Standard AS4292.7 would apply to ZZR. The aim being to give the ZZR investigation team a broad understanding of what a typical investigation would look like, and how they could improve safety through the investigative process.

The Zig Zag railway was built in the 1860s, to transport people and produce from the western plains of NSW to Sydney. It was replaced in 1910 by a 10 tunnel deviation. During the 1970s the line was rebuilt as a fully operational tourist railway using narrow gauge track and rolling stock from Queensland, South Australia and Western Australia. The trains, track and rolling stock are maintained and operated by the Zig Zag Railway Co-op Ltd, a voluntary, “not for profit’ co-operative.

The ATSB would like to thank the board of Zig Zag Railway for giving us the opportunity to visit and play a part in helping to return the Zig Zag Railway to operational status.

From 2 November 2015, the ATSB will start investigating accidents and incidents on Western Australia’s metropolitan and regional passenger, and freight rail networks. 

This new focus in Western Australia will see more investigations conducted across a greater range of safety matters. It will also mean that the ATSB will be the mandatory notification point for all Category-A occurrences within Western Australia.  

The changes are a result of Western Australia joining the national rail safety scheme. The Office of the National Rail Safety Regulator (ONRSR) will also assume regulatory oversight in the state.

Western Australia now joins South Australia, Tasmania, Northern Territory, New South Wales, Victoria and the Australian Capital Territory in the national scheme.

Reporting rail safety occurrences

• ATSB is the national independent, no-blame safety investigator for rail incidents and accidents.
• Report all Category-A rail occurrences to the ATSB on 1800 011 034.

More information on rail accident or incident notifications.

The ATSB has released its latest Bulletin of short investigations covering incidents involving light aircraft and helicopters.

• Issue 44 of the Bulletin features 10 safety investigations.

The ATSB has released its latest Bulletin of short investigations covering incidents involving light aircraft and helicopters.

The Bulletin also highlights important safety messages for the broader aviation community, drawing on earlier ATSB investigations and research.

Released periodically, the Bulletin provides a summary of the less-complex factual investigation reports conducted by the ATSB. The results, based on information supplied by organisations or individuals involved in the occurrence, detail the facts behind the event, as well as any safety actions undertaken or identified.

Issue 44 of the Bulletin features 10 safety investigations:

Piston aircraft

• Landing gear malfunction involving a Cessna 210, VH-SMP
• Collision with terrain involving a Victa 115 Airtourer, VH‑MUV
• Separation issue involving a Pacific Aerospace CT/4B, VH-YCU, and a Diamond DA 40, VH-UNV
• Collision with terrain during landing, involving a PA32 aircraft, VH-BDG
• Engine failure and collision with terrain involving a Cessna 210, VH‑ERU
• Collision with terrain involving a Grumman G164, VH-LKN
• Separation issue involving a Cessna 404, VH-ANM, and a Cessna 172, VH MJK

Helicopters

• Engine failure involving an Enstrom 280, VH-YHD
• Windscreen fogging and collision with terrain involving a Robinson R22, VH-RBT
• Loss of control involving a Bell 206L3, VH-BLV

Follow this link to: Aviation Short Investigation Bulletin - Issue 44

• Managing fatigue is everyone’s responsibility. Together, employees and employers have clear responsibilities to manage fatigue.

Fatigue is a safety risk that needs to be managed. When working airside it is important to recognize the signs of fatigue and be aware of how it could affect your performance on the job.

Fatigue can significantly delay your response and reaction times, impair reasoning, reduce vigilance and affect hand- eye coordination.

But the greatest single threat is being unaware that it is happening.

Fatigue is brought on by the amount of time you’ve spent on the job and the type of work you have been doing. It is also attributable to what you are doing when not at work. If you have another job, especially one that requires long hours and involves strenuous activity or long periods of concentration, you’re more prone to fatigue when at work.

Managing fatigue is everyone’s responsibility.

What are the effects of fatigue?

Fatigue reduces your ability to concentrate. Specifically, the effects include:

• slowed reaction times
• reduced vigilance
• slower mental abilities
• memory problems
• poor communication
• reduced alertness
• poor decision-making
• fixation on a single task
• actually falling asleep while working.

Tips for countering fatigue

Be conscious of the quality of your sleep – if your sleep quality has been poor, it may not be safe to keep working.

When assessing your potential fatigue levels, take into account all activities you do throughout your day.

Proper nutrition and plenty of water helps keep you alert:

• minimize fatty and high-sugar foods
• don’t rely on caffeine (coffee, energy drinks) as it only provides short-term relief from the effects of fatigue.

Remember, getting enough quality sleep is essential to avoiding fatigue.

What’s your fatigue risk?

Use the following checklist to give yourself an objective assessment of your fatigue risk:

• Did you have less than eight hours sleep last night?
• Have you missed out on adequate sleep over the previous nights?
• Has your sleep been disrupted?
• Have you been awake and/or at work for an extended period?
• Have you had less than six hours sleep in the last 24 hours (or less than 14 hours sleep in the last two days)?
• Have you had a recent illness or injury?
• Are you affected by medication, other drugs or alcohol?

If your answer to one or more of these questions is yes or even maybe, you’re at a higher risk of fatigue.

Share this information with your co-workers and family. Ask them to keep an eye on your performance. Do the same for others you work with.

Managing fatigue is everyone’s responsibility. Together, employees and employers have clear responsibilities to manage fatigue.

Employers have a duty of care to provide safe work schedules that permit adequate time for an employee to sleep, rest and recover as well as fulfil their social and domestic responsibilities.

Employees also have a duty of care to use their time away from work to get enough sleep and recovery time so they can complete their work duties safely and responsibly.