Research and Analysis Report

In 2007 the Australian Transport Safety Bureau (ATSB) produced the inaugural edition of Australian Aviation Safety in Review as part of the ATSB's role to enhance public awareness of aviation safety. The Review has been developed to provide a readily accessible analysis of the Australian aviation sector, with a strong focus on safety trends. This publication covers all major categories of aircraft operations, from regular public transport (RPT) to general aviation (GA), and includes some information about sports aviation.

Demographic and activity data on Australian aviation is provided in order to provide a context within which to examine accident trends. Accidents are presented both in terms of the raw number of accidents and as rates per 100,000 hours flown, to enable a comparison between operational categories. The latest year for which flying hours are available is 2006. Accordingly, this edition of the Australian Aviation Safety in Review covers the five calendar years 2002 to 2006, offering insights and information about key trends and emerging issues.

This is the second edition of Australian Aviation Safety in Review and the ATSB intends to update this report in the future as a means of informing both the aviation community and the wider public about Australian aviation accident and activity trends.

The ATSB released this report in June 2008. Since that time, the ATSB has received comments regarding the technical accuracy of the removal of particles from high efficiency particulate air filters (page 6 of the report). This report has been amended accordingly and contains an additional reference for readers on page 10.

Every year, an increasing number of people undertake air travel. Whether for business or pleasure, these journeys should be safe and enjoyable. However, there is continuing public concern about whether, or to what extent, aircraft cabins represent an increased risk of transmission of infectious disease. The purpose of this report was to review the current literature on the potential risk of disease transmission within an aircraft cabin.

The evidence suggests that passengers' health is not greatly at risk through air travel and widespread infections are unlikely. Although there have been cases of infectious disease transmission in aircraft cabins, there is evidence that such transmission was primarily due to the crowding together of a large variety of people in a confined space, not specifically due to aircraft cabin conditions. This suggests that the risk of transmission within an aircraft cabin is no greater than in other crowded and confined spaces, provided circulation and filtration systems are working properly. Perhaps of greater concern is the opportunity for infection to spread in airport terminals, where passengers who are travelling to or from many destinations are gathered together.

The increase in international travel has also heightened the risk for the global spread of infectious diseases. It is not possible to predict when the next pandemic will occur or how long it will last but many health officials think that it's only a matter of time. Although the increase in international air travel could assist with the spread of a future influenza pandemic, the aviation industry will also play a critical role in mitigating the consequences.

For many decades, fibre composites have been replacing traditional aluminium structures in a wide variety of aircraft types. From the first all-composite kit plane released in 1957, composites are widespread today in commercial aircraft and many other aircraft types. This is due to the cost and weight savings that materials such as glass/phenolic and carbon/epoxy offer aircraft manufacturers over aluminium, while maintaining or surpassing its strength and durability.

This study provides an overview of fibre composite use in aircraft and the issues associated with its use, with a focus on aircraft operating in Australia that contain these materials. There are almost 2,000 aircraft on the Australian civil register made of, or containing, fibre composite materials. This includes most of the mainline jet fleet, effectively all sailplanes and gliders, many popular general aviation aircraft, and a third of the growing amateur-built aircraft category.

There is a lot of conflicting or incorrect information in the aviation community about the safety and capability of fibre composite materials. Composite structures behave very differently under normal loads than equivalent metal structures. Fatigue and corrosion have been proven through trials of composite repair patches to be much less prevalent in composites compared with metals. Subsurface damage such as delamination however can go undetected for long periods and result in sudden catastrophic failure. It is important that operators of fibre composite aircraft be aware of correct detection and repair procedures for the unique types of damage that occur to composites.

First responders involved in post-crash cleanup operations have expressed concerns about the long-term effects from exposure to carbon fibres released from burning composites. Fibre dust can pose an inhalation risk similar to asbestos. Released fibres or splinters are needle-sharp, and can cause skin and eye irritation. In the event of a post-crash fire, smoke and toxic gases are also released from decomposing composites, presenting further health risks.

The objective of the project is to analyse GPWS warnings in Australia with a view to addressing ICAO steps (e) Investigation of GPWS warnings and (f) Reduction of unwanted warnings, of the circular AN11/1.1.1993/61.

CFIT accidents are the most severe aircraft accidents. These kinds of accidents occur when an otherwise airworthy airplane is inadvertently flown into the ground or water. The number of fatalities per accident is extremely high as compared to any other type of accident. They also generally result in complete destruction of the airplane. If CFIT accidents were to be completely prevented, approximately half of the worldwide fatalities in aircraft accidents would also be prevented. CFIT accidents have a high leverage for safety improvement.

This study reviewed safety trends in the Australian aviation charter industry for the period 1 January 2001 to 31 December 2006. It builds on a previous descriptive study that reviewed immediately reportable matters (IRMs) for regular public transport (RPT) aviation operations. Together, charter and RPT operations make up the air transport sector in Australia. Similar to the previous report, a subset of generally more serious IRMs were reviewed including: accidents; violations of controlled airspace (VCA); breakdowns of separation (BOS) and airproxes; fire, smoke, explosions or fumes; crew injury or incapacitation; fuel exhaustion; and uncontained engine failures. Charter flying activity, measured as flying hours and number of charter operators, was also reviewed.

Hours flown in charter operations initially declined over the study period with an increase across 2004 to 2006. However, the number of hours flown in 2006, the latest year reviewed, was not as high as the historical peak in charter hours observed in 1999. The number of charter operators decreased in 2005 and 2006, so fewer operators conducted more of the hours flown in those years.

Total IRMs reported and the IRM categories examined, were generally stable with the exception of accidents. The rate of accidents decreased significantly between 2001 and 2006. Occurrences involving fire, smoke or fumes, and airspace-related occurrences such as VCA and BOS/airprox, remained stable with no statistically significant increase in the rate across 2001 to 2006. The rate of fuel exhaustion occurrences for the period was 0.4 occurrences per 100,000 hours flown. The other IRM categories; crew injury/incapacitation and uncontained engine failures, were rare.

This review provided encouraging data on the charter accident rate, emphasised the stability of the rate of airspace related occurrences, and the rarity of uncontained engine failures and crew incapacitation in charter operations.

Safety summary

Update

This statistical report shows aviation occurrence and activity data over the 10-year period from 2010–2019 to provide an insight into current and possible future trends in aviation safety. The previous edition (AR‑2020‑014) published in April 2020 presented 10 years of occurrence data, but aviation activity data was only available for 2014–2018 as 2019 activity data was not available at the time of publishing. This report is an update of the previous edition with the addition 2019 aviation activity data which also allows all occurrence rates to be presented for the period 2014–2019. This was done to present safety information to industry in a timely manner.

The purpose of this report

Each year, thousands of safety occurrences involving Australian aircraft and foreign‑registered aircraft operating in Australia are reported to the Australian Transport Safety Bureau (ATSB).

This report is part of a series that aims to provide information and statistical data to the aviation industry, manufacturers and policy makers, as well as to the travelling and general public, about these aviation safety occurrences. In particular, the data can be used to determine what can be learned to improve transport safety in the aviation sector.

Aviation activity data used in this report was all sourced from the Bureau of Infrastructure, Transport and Regional Economics (BITRE) which collects and compiles this data from reports submitted by airlines, and from other aircraft operators through its General Aviation Activity Survey.

This statistical report presents interactive web versions of all tables and graphs to allow the user to display aviation occurrence data in the format of their choice.

What the ATSB found

2019

In 2019, 222 aircraft were involved in accidents in Australia, with a further 155 aircraft involved in serious incidents (an incident with a high probability of becoming an accident). There were 35 fatalities from 22 fatal accidents. The number of fatalities was consistent with the average of the previous nine years (32.3 fatalities per year), and the number of fatal accidents was also consistent with its average (23.1 fatal accidents per year).

There have been no fatalities in scheduled commercial air transport in Australia since 2005.

2010 to 2019 accidents and incidents

Between 2010 and 2019, over 90 per cent of accidents and fatal accidents, and over 80 per cent of serious incidents, involved aircraft operating within the general aviation and recreational aviation sectors. In contrast, due to the more stringent reporting requirements for air transport operations, three‑quarters of reported incidents involved aircraft operating within commercial air transport.^[1]

Considering all years in the period, the number of general aviation (GA) fatalities and fatal accidents decreased. The number of fatalities and fatal accidents within commercial air transport and recreation aviation remained relatively constant.

Since 2016, remotely piloted aircraft (RPA) have surpassed helicopters to become the second most common aircraft type involved in an accident. However, over this period (2016–2019) there were no injuries involving an RPA, whereas there were 16 fatal, 30 serious, and 44 minor injuries resulting from an occurrence involving a helicopter.

Further, the number of manned aircraft experiencing near encounters with an RPA also increased significantly over the study period.

2014 to 2019 accident rates

Statistics in this report have been organised around the type of aircraft activity being conducted, rather than the operational regulation. Due to the availability of activity data (departures and hours flown data), it was only possible to calculate accident and fatal accident rates over the six‑year period 2014–2019.

Over this period, test and ferry flights, recreational flights involving an aircraft registered with Recreational Aviation Australia (RAAus), followed by pleasure and personal transport, had the highest accident rates. Community services flights, followed closely by test and ferry flights, had the highest fatal accident rates. (However, as there was only one fatal accident involving an aircraft conducting community service flights between 2014 and 2019 there is a high level of statistical uncertainty associated with this rate). For aircraft types, recreational aeroplanes, followed by commercial balloons had the highest accident rates. Also, recreational aeroplanes had the highest fatal accident rate.

Commercial air transport

There were no fatalities within commercial air transport in 2019.

Over the full study period (2010–2019), more than half of all serious incidents and the majority of accidents and fatal accidents for commercial air transport operators involved aircraft conducting non‑scheduled activities, predominantly passenger transport charters. There were no identified increases or decreases in the number of accidents or serious incidents, however, the number of reported incidents for aircraft conducting scheduled international flights and commercial freight increased over the 10 years.

Between 2014 and 2019, around three‑quarters of the hours flown, and approximately one‑half of all departures, within commercial air transport, were operated by scheduled domestic or international operations.

Concerning activities within commercial air transport, passenger transport charters had the highest accident and fatal accident rates (per hour flown). However, commercial freight had the higher number fatal accidents per departure.

For specific aircraft types, within commercial air transport, balloons had an accident rate (between 2014 and 2019) more than 10 times higher than for aeroplanes or helicopters. However, there was only one fatal accident involving a commercial balloon in the 2010 and 2019 timeframe.

Most commercial accidents and serious incidents were operational in nature (typically aircraft control and terrain collisions). The majority of incidents were environmental (mainly birdstrikes).

General aviation

In 2019, there were 17 fatalities in GA.

Over the 10 years, around one‑third of GA accidents and 45 per cent of fatal accidents involved aircraft conducting sport and pleasure flying. Aerial work accounted for a further 37 per cent of GA accidents and 33 per cent of fatal accidents. The number of GA accidents per year increased over the period, with aerial work identified as the primary contributor. Conversely, there was a decrease in the number of fatal accidents, resulting in a decrease of around one fatal accident, or 1.4 fewer fatalities, per year.

There was also an increase in the number of reported incidents for GA aircraft conducting instructional flying.

Between 2014 and 2019, around 40 per cent of GA hours flown were conducted within aerial work, with instructional flying accounting for a further 30 per cent. Sport and pleasure flying made up around 14 per cent.

The rate of GA accidents decreased over the six years 2014–2019. The main contributors to this decline were sport and pleasure flying, and own business travel.

Between 2010 and 2019, there was an increase in the number of GA RPA accidents per year; this primarily resulted from a significant increase in the overall number of survey and photographic accidents.

Overall, there was a decrease in the accident rate for aeroplanes conducting GA flying. The main contributors to this decrease were identified as aeroplanes conducting sport and pleasure flying, and own business travel.

Over the 10 years, the majority of GA accidents, incidents and serious incidents were related to operational or technical issues. Additionally, the majority of fatal accidents were also attributable to operational issues.

Further, the number of GA operational-related accidents and serious incidents, per year, increased over the period. Instructional flying was the main contributor to this operational-related increase. Additionally, there was an increase in the number of accidents and serious incidents of a technical nature; largely attributable to aerial work operations (especially those conducted using an RPA).

Recreational aviation

In 2019, there were 18 fatalities involving an aircraft conducting recreational flying.

The accident rate for recreational flying decreased between 2014 and 2019, with Recreational Aviation Australia (RAAus) registered aircraft having the greatest contribution to this reduction.

Aeroplanes had the highest accident and fatal accident rates of any recreational aircraft type.

Similar to GA, over the full study period (10 years), the majority of recreational accidents and serious incidents were operational (mainly terrain collisions) or technical (primarily engine failure or malfunction) in nature.

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1. Includes scheduled airline flying as well as non-scheduled passenger-carrying activities such as charter, medical transport, and joyflight/sightseeing charters, as well as freight

Safety Summary

Why the ATSB undertook this research

On 6 April 2020, the Royal Commission into National Natural Disaster Arrangements (RCNDA) issued a notice to give information to the ATSB. Within this notice, was the requirement to ‘describe any key operational and safety challenges encountered in coordinating and responding to fires associated with the use of aircraft and aerial fire fighting techniques’. This statistical report forms part of the ATSB’s response to the Royal Commission’s notice to give information.

In addition, since 2018 the ATSB has commenced six investigations involving aerial firefighting aircraft, this includes the high profile investigation (AO-2020-007) into the collision with terrain involving a Lockheed C‑130 near Cooma, New South Wales, on 23 January 2020.

What the ATSB found

Aviation activity relating to aerial firefighting has increased over recent bushfire seasons. However, official exposure data (hours flown and flights for Australian-registered aircraft) before 2014 and beyond 2018 were not available to the ATSB for this report. Estimates of aerial firefighting activity for the most recent bushfire season (2019–20) have been around four times higher than other recent bushfire seasons.

There were more reported occurrences^[1] involving aerial firefighting aircraft in Australia in the financial year covering the last bushfire season (between July 2019 and March 2020) than any financial year since July 2000. In addition, there were two fatal accidents since August 2018, whereas the previous 17 years only had three fatal accidents. Further, the number of occurrences per financial year increased steadily since 2016–17. Given the increased activity, these results could be expected and probably do not indicate a significant increase in the risk per flight. (A more extensive analysis would incorporate exposure data for the full 20-year study period if the data was available.)

Over the full 20-year study period, all fatal accidents and around 40 per cent of other occurrences happened in New South Wales.

Around three quarters of aerial firefighting occurrences involved Australian VH‑registered aircraft. Foreign‑registered aircraft accounted for the bulk of the remaining occurrences. Probably reflective of increased activity, the proportion of occurrences involving foreign‑registered aircraft increased significantly over the study period. Between July 2019 and March 2020, foreign‑registered aircraft were involved in two thirds of more severe occurrences (serious incidents, accidents and fatal accidents).

The average maximum take‑off weight (MTOW) of aerial firefighting aircraft involved in a reported occurrence increased significantly over the study period. Foreign‑registered aircraft, which had an average MTOW around 10 times that of VH‑registered aircraft, contributed most to this increase.

Between 2014 and 2018 (the period with available exposure data – departures and hours flown), the rate of reported occurrences involving VH‑registered aircraft was consistent between aeroplanes and helicopters. VH‑registered piston‑powered helicopters had around double the rate of more severe occurrences than turboshaft helicopters.

Half of all reported aerial firefighting occurrences and four fifths of more severe aerial firefighting occurrences were operational in nature, typically terrain collisions, with around one quarter of the more severe occurrences associated with aircraft control. Further, around one quarter of more severe occurrences involved a technical issue, most commonly engine failure or malfunction.

Additional risks to those inherent to low‑level flying can be seen in higher occurrence rates compared to other low‑level flying activities. Between 2014 and 2018, VH‑registered aerial firefighting aircraft had higher rates of communication‑related occurrences, flight preparation/navigation operational occurrences, aircraft separation occurrences, operational non‑compliance occurrences, airframe‑related technical issues, and encounters with remotely piloted aircraft. Aerial firefighting had lower rates for terrain collision and aircraft control related occurrences.

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1. Occurrences are incidents, serious incidents, accidents and fatal accidents that have been reported to the ATSB. This report includes all occurrences involving aerial firefighting aircraft. This is to highlight potential safety risks to aircraft conducting aerial firefighting, and includes events where actions of the aerial firefighting crew did not lead to the occurrence.

Why we have done this report

Occurrences involving aircraft striking wildlife, particularly birds, continue to be the most common aviation occurrence reported to the ATSB. Strikes with birds are a potential safety risk and present a significant economic risk for aerodrome and aircraft operators. The aim of the ATSB’s statistical report series is to provide information back to pilots, aerodrome and aircraft operators, regulators, and other aviation industry participants to assist them with managing the risks associated with bird and animal strikes. This report updates the last edition (published in 2016) with data from 2016 – 2017.

What the ATSB found

Between 2008 and 2017, there were 16,626 confirmed birdstrikes reported to the ATSB. The number of reported birdstrikes has increased in recent years, with 2017 having the highest on record with 1,921. Despite being a high frequency occurrence, birdstrikes rarely result in aircraft damage or injuries. Of the 16,626 birdstrikes in this reporting period, 99.8 per cent were classified as incidents, while 19 (~0.1 per cent) were classified as accidents and another five (~0.03 per cent) as serious incidents. Nine birdstrikes, or approximately 0.05 per cent of the birdstrikes in the ten years, resulted in minor injuries to pilots or passengers. There were no reported serious injuries or fatalities associated with a birdstrike occurrence in the ten-year period.

Domestic high-capacity aircraft were those most often involved in birdstrikes, and the birdstrike rate per aircraft movement for these aircraft was significantly higher than all other categories. Both the number and rate of birdstrikes per 10,000 movements in high-capacity operations have increased in the past two years 2016 – 2017. In contrast, the number of birdstrikes in low-capacity operations and general aviation has remained relatively consistent in the most recent two years.

The number of birdstrikes involving a bird ingested into an engine in high-capacity air transport operations has risen in recent years with about one in ten birdstrikes for turbofan aircraft involving a bird ingested into an engine. Additionally, over the ten-year reporting period, there have been 11 occurrences involving one or more birds ingested into two engines of turbofan-powered aircraft.

The five most commonly struck flying animals in the 2016 to 2017 period were flying foxes, galahs, magpies, and ‘bats’ (many of which were likely to be flying foxes) and plovers.

Compared to birdstrikes, non-flying animal strikes are relatively rare, with 396 animal strikes reported to the ATSB between 2008 and 2017. The most common animals involved were hares, rabbits, kangaroos, wallabies, and foxes. Damaging animal strikes mostly involved kangaroos and wallabies.

Safety message

Australian aviation wildlife strike statistics provide a reminder to everyone involved in the operation of aircraft and aerodromes to be aware of the hazards posed to aircraft by birds and non-flying animals. The growth of reporting to the ATSB over the last 10 years has helped to understand better the nature of birdstrikes, and what and where the major safety risks lie. As such, timely and thorough reporting of birdstrikes is paramount. This assists the aviation industry to manage better their safety risk. Over the ten years from 2008 to 2017, about 40 per cent of all birdstrikes reported to the ATSB contained no species information. The more detailed the information is provided to the ATSB, the more accurate and useful reports like this one will be.

Why the ATSB did the research

Fatigue is an inevitable risk in aviation. As it cannot be completely eliminated, it must be managed. Data on fatigue and its impact on air transport safety is generally only obtained if there is an incident or accident. As a result, there is generally a lack of understanding of the baseline level of fatigue in day-to-day Australian air transport across operators.

To provide the air transport industry, regulators and policy makers with further insights into industry perceptions of fatigue, the ATSB conducted a survey of commercial pilots engaged in passenger, freight, and aeromedical operations in the second half of 2016. To understand the reported level of fatigue during normal operations, the survey aimed to discover the amount of sleep and rest obtained by pilots, as well as their perceptions on the length of rests and duty times. The survey also aimed to capture data on the organisational aspects of fatigue, including how pilots feel about removing themselves from duty because of fatigue experienced and how they think management perceive this behaviour.

What the ATSB found

The majority of survey respondents reported they were sufficiently well rested by the end of their last duty. Over half of pilots reported having 7 hours of sleep or more in the previous 24 hours, and over 60 per cent reported having more than 14 hours in the previous 48 hours, at the end of the last flight. The survey also found a small but significant number of pilots, 10 per cent and 17 per cent, who reported obtaining less than 5 hours of sleep in the previous 24 hours, or less than 12 hours in the previous 48 hours, respectively, at the end of their last flight. These sleep thresholds have been shown to be associated with impaired performance.

Less sleep on duty was more prevalent for international and domestic jet airline pilots than other air transport pilots (regional, charter and aeromedical). While around one third of the respondents reported obtaining the same amount of sleep at home as they did while on duty, around half of international and domestic pilots reported obtaining less hours of sleep on duty than at home. About 15 per cent of international pilots responded they had no rest during their last international flight.

Domestic pilots completed duties on a stand-by day more often than other pilots. Some believed the rest period between duties was too short, duty periods were too long, and access to food during duties was more difficult compared with other pilots, indicating some pilots within this group have negative perceptions of rest opportunities provided by their employers.

Over 90 per cent of pilots indicated their employer offered a formal process for removing themselves from duty due to fatigue. About one third of respondents indicated they removed themselves from duty at least once in the past year, mostly between one and three days. The pilots who removed themselves from duty generally perceived their actions left a negative impression with management (with the exception of aeromedical pilots) and did not feel comfortable doing so.

Safety message

Responsibility to manage the risk of fatigue lies with both the individual pilot and organisation. It is the individual pilot’s responsibility to use rest periods to obtain adequate sleep and to remove themselves from duty if they feel fatigued. It is important for operators to implement policies to reduce the likelihood of fatigue-related issues through rostering practices and by providing an organisational culture where crew can report fatigue in a supportive environment. The results of this research suggest that operating in circumstances conducive to fatigue is an ongoing challenge for a proportion of Australian air transport pilots.

Why the ATSB did this research

Stall warning events have always been an area of interest for airlines and aviation safety investigators as they indicate that an aircraft is operating at the margins of safe flight. As these occurrences are reportable to the ATSB, the ATSB can analyse trends across airlines and Australia. By publishing such analysis, it is hoped that the wider aviation industry will be able to learn from the experience of others.

What the ATSB found

A review of 245 stall warnings and stall warning system events reported to the ATSB over a 5–year period showed that almost all were low risk events which were momentary in duration, and were responded to promptly and effectively by the flight crew to ensure positive control of the aircraft was maintained. No occurrences resulted in a stall or an irrecoverable loss of aircraft control, and only a few were associated with minor injuries to passengers or crew (generally those that occurred in severe turbulence) or a temporary control issue.

About 70 per cent of stall warnings reported to the ATSB were genuine warnings of an approaching stall, with the remainder being stall warning system problems. In only a minority of cases were system problems reported that resulted in false or spurious stall warnings such as a stick shaker activation.

Stall warnings (and in particular stick shaker activations) were well reported by Australian air transport operators, and occurred in a range of flight phases and aircraft configurations, not exclusively those related to low speed, high pitch attitude flight, or flight in poor meteorological conditions. Fifty-five per cent occurred in visual (VMC) conditions, and those in instrument (IMC) conditions mostly occurred in cruise. In typical stall warning events during cruise, the aircraft was operating at an altitude where there was a narrow band (about 20 knots) between the maximum operating speed and the stall warning speed (VSW). Common precursors to these events were rapid changes of pitch angle or airspeed. In about one-fifth of these occurrences, the stall warning system was activated when the autopilot tried to correct the aircraft’s speed or flight path due to a disturbance. Stall warnings during VMC flight were most common on approach, often involving aircraft being affected by turbulence while manoeuvring around weather.

The ATSB identified 33 serious and higher risk incidents in which a stall warning occurred. The majority of these involved brief stick shaker activations, and were associated with moderate or severe turbulence. Most happened on approach to land, when aircraft were in a low speed, high angle of attack configuration, and in several cases the stall warning speed was higher than normal (due to a higher wing loading (g) factor in a turn, or an incorrect reference speed switch setting). In these cases, the risk of a stall developing was increased by a lack of awareness of decreasing airspeed and increasing angle of attack prior to the stall warning, and/or an approach to land where the flight crew were focused on trying to correct the approach prior to the stabilised approach height instead of conducting a go-around.

Safety message

Stall warnings occur in normal operations, and are normally low risk events. In Australia, even the most serious events have not resulted in a loss of control, and have been effectively managed by flight crew to prevent a stall from occurring. To avoid higher risk stall warning events, pilots are reminded that they need to be vigilant with their awareness of angle of attack and airspeed, especially during an approach on the limits of being stable.