Research and Analysis Report

October Audit Report of the Australian Transport Safety Bureau (ATSB) of Australia (Field work conducted in Canberra, 31 May to 4 June 2004).

Executive Summary

The ICAO audit team commended the positive and professional approach of the ATSB in proactively seeking the audit. The team was highly satisfied with the legislative and organizational framework established by Australia and the ATSB enabling the conduct of aircraft accident and incident investigations. Nevertheless, the audit focussed on all areas related to accident and incident investigation and found possible areas of improvement.

The Transport Safety Investigation Act 2003 (TSI Act) is the legislative framework for transport safety investigations in aviation, marine and the interstate rail system. The TSI Regulations 2003, giving effect to the TSI Act, came into force at the same time as the TSI Act on 1 July 2003. Together, the TSI Act and the TSI Regulations comply with Annex 13 requirements and have the necessary provisions to enable the ATSB to effectively conduct or participate in aircraft accident and incident investigations. The ATSB has notified its differences to ICAO in respect of Annex 13. While section 17 of the TSI Act automatically endorses any amendments to ICAO SARPs and gives them the force of Australian law, the ATSB has not yet formalized its process for reviewing the SARPs and identifying its differences.

The ATSB has its headquarters in Canberra and two regional offices (in Brisbane and Perth). The ATSB is adequately organized and supported by appropriate technical and non-technical staff. However, the ATSB has not established a process for determining staff requirements needed to adequately complete all tasks in its area of responsibility. When establishing its Business Plan, the ATSB took into consideration the Departments Portfolio Budget Statements; however, the ATSB developed the performance indicators of its business plan based on the budget allotted to it. As a result, the number of smaller investigations and the scope of more complex investigations change depending on the availability of financial resources. Ideally, the number of accidents, serious incidents and associated safety issues should be used as a basis for the determination of the budget. Finally, the ATSB has not put in place a system for the control and integration of the regional offices into the functionality and organizational structure of the Canberra office. The ASTB has signed several Memorandums of Understanding (MOUs) with other organizations and authorities but some important MOUs have yet to be finalized.

The ATSB is commended for having developed a very comprehensive training policy and programme, which includes a diploma course entitled Transport Safety Investigation (TSI) Diploma Course. The ATSB training policy requires all personnel who joined the ATSB after 1 January 2000 to complete the TSI Diploma Course. Investigators who have taken or are currently taking this course maintain structured training files in accordance to the training programme followed. However, not all investigators have undergone the TSI Diploma Course. As a result, some investigators are not part of the formal diploma programme and do not maintain a documented record of all the types of training and briefings that they have been provided with.

The ATSB provides its staff with all the necessary facilities and equipment. However, the review of some of the equipment to be used by investigators revealed shortcomings in serviceability and record keeping. The ATSB has developed a new Safety Investigation Policy and Procedures Manual but has not yet formally approved it. The procedures established by the ATSB for the notification, investigation and reporting of aircraft accidents and incidents, found in several manuals, are comprehensive and in conformity with Annex 13 requirements. The ATSB focuses primarily on fare-paying passengers and on fatal accidents (unless they involve sport aviation), therefore some accidents that are considered to have little potential benefit for the prevention of re-occurrences may not be investigated in detail. In such cases, the ATSB does not necessarily attend the scene, conduct an in-depth investigation or produce an extensive report. Autopsy reports are obtained by the ATSB but are not always complete. By Australian legislation, medical examination and toxicological testing of surviving flight crew and aviation personnel cannot be performed after an accident.

Safety recommendations are issued by the ATSB in conformity with Annex 13 requirements. ADREP Preliminary Reports and Data Reports sent by the ATSB to ICAO were incomplete, partly due to the differences in the taxonomy format. Since the ATSB is in the process of acquiring a new accident and incident data reporting system, it is recommended that the new database system be ADREP-ECCAIRS compatible in order to facilitate reporting and international exchange of data. Between 1988 and February 2004, the ATSB managed a voluntary incident reporting system named Confidential Aviation Incident Reporting (CAIR). A new voluntary non-punitive incident reporting scheme, entitled Aviation Self-Reporting Scheme (ASRS), replaced the CAIR on 21 February 2004 but has not yet been broadened to receive CAIR reports, pending further legislative measures. In addition to accident and incident investigation, the ATSB undertakes safety data analysis and research. All the ATSB reports, safety recommendations and key safety information are available on the ATSB website.

Updated January 2008

Executive summary

Australian aviation is, by world standards, extremely safe. Fatal accidents in regular public transport (RPT) operations are low and, since the late 1960s, have been confined to low capacity operations. Australia has not had a high capacity RPT fatal accident since 1968 and has not had a RPT jet fatal accident. 

The vast majority of Australian civil fatal aircraft accidents occur in general aviation (GA) operations. This study examined Australian ‘VH-registered’ civil aircraft involved in GA fatal accidents for the period 1991 to 2000, and covers fatal accident numbers and rates by aircraft type and operational grouping, timing of accidents, injury levels, pilot demographics and fatal accident types. 

Between 1991 and 2000 inclusive, there were 215 fatal accidents and 413 associated fatalities. Over the ten-year period there were 1.2 GA fatal accidents per 100,000 hours flown. The annual fatal accident rate decreased from 1.6 fatal accidents per 100,000 hours flown in 1991 to 0.9 in 2000. While this decrease was not statistically significant, subsequent data to the end of 2002 do indicate a statistically significant decrease. Statistically significant variations were identified at certain times of the day and week, indicating that occurrences were more likely to be fatal accidents at certain times. The rate of general aviation fatal accidents was found to be significantly higher during the evening between 1700 and 2059 than the rest of the day and the private/business fatal accident rate was found to be significantly higher over the weekend than during the week. Reasons for these findings could not be clearly identified. 

The population of pilots involved in fatal accidents was compared with the present population of active general aviation pilots against certain demographic criteria. 

The risk of a fatal accident per hour flown was greater for pilots who had between 50 and 1,000 hours aeronautical experience than pilots who had more than 1,000 hours experience. However, with the low number of pilots involved in fatal accidents, small changes in the demographics of pilots involved in fatal accidents can lead to large changes in the risk associated with different age and experience groupings. 

The fatal accidents were grouped using a classification scheme developed within the ATSB so that a consistent and useful description of the accident types could be achieved. The re-classification and re-coding of the accidents enabled a more accurate description of the larger groupings of fatal accidents, which could provide a greater opportunity to accurately target specific risk areas in general aviation operations. 

The majority of fatal accidents (82 per cent) fell into three main groups: 

• controlled flight into terrain
• managed flight into terrain
• uncontrolled flight into terrain. 

For the purpose of this report these accident types were defined as: 

• Controlled flight into terrain (CFIT) - an event where an aircraft collided with obstacles, objects or terrain during powered, controlled flight with little or no awareness on the part of the pilot of the impending impact. 
• Managed flight into terrain (MFIT) – an event where an aircraft collided with obstacles, objects or terrain while being flown under limited control or reduced performance, with insufficient height/performance to reach a designated landing area. 
• Uncontrolled flight into terrain (UFIT) - an event where an aircraft collided with obstacles, objects or terrain after control of the aircraft was lost in-flight (includes cases where the pilot became incapacitated) but the aircraft structure did not change prior to impact. 

UFIT fatal accidents were the most prevalent of the fatal accident types (46 per cent), followed by CFITs (30 per cent) and MFITs (6 per cent). Accidents that did not fall into one of these three main groupings were categorised separately, but were not sub-categorised to the same extent. 

The vast majority of low-level UFIT fatal accidents (approximately 90 per cent) could be described as accidents where the pilot’s control inputs (or lack of inputs) initiated a loss of control. In almost a quarter of these cases, turbulence or windshear may have also contributed to the loss of control. In contrast, UFIT fatal accidents during ‘normal’ operations were more likely to have had an initiating factor such as a loss of engine power, loss of reference to the external environment, aircraft system or airframe problem, pilot incapacitation etc., with around 20 per cent being primarily the result of pilot action or inaction. This disparity suggests that many of the loss of control events during low-level operations could have been recovered had the aircraft been at a greater height. For fixed wing operations, a higher proportion of UFIT accidents were private/business operations (2/3), compared with MFIT or CFIT accidents (1/2). 

The next largest fatal accident grouping was controlled flight into terrain accidents (CFITs). The majority of CFIT fatal accidents occurred during low-level operations, when the pilot could see the environment. Most of these accidents were wirestrikes. Pilots involved in CFIT fatal accidents who were flying aircraft unnecessarily low, accounted for a quarter of all the fatal CFITs and 42 per cent of fatal CFITs during low-level flying. The large majority of CFIT fatal accidents from ‘normal’ operations occurred when the pilot was not able to see the outside environment, whether operating under VFR or IFR. 

The accident classifications used in this report promote greater understanding of the types of fatal accidents that have occurred by focusing on the state of the aircraft at the time it sustained damage or a person was fatally injured. The events or circumstances that precipitated the accident types highlight areas where it is possible to intervene in the sequence of events to avoid a fatal accident or reduce the severity of an accident. 

The characteristics of each accident group were markedly different, and the sub-categorisation of accidents within each group was therefore also different. The majority of CFIT fatal accidents were initiated by an impact with an obstacle or terrain. In UFIT accidents the event that led to the situation becoming a fatal accident generally happened while the aircraft was still flying. MFIT accidents were generally fatal because of the nature of terrain encountered at the time of impact, rather than because of the nature of the event that precipitated the accident.

Cannabis is a commonly used recreational drug, which has widespread effects within the body. Smoking is the most common form of administration. The adverse effects of cannabis on behaviour, cognitive function and psychomotor performance are dose-dependent and related to task difficulty. Complex tasks such as driving or flying are particularly sensitive to the performance impairing effects of cannabis. Chronic cannabis use is associated with a number of adverse health effects, and there is evidence suggesting the development of tolerance to chronic use as well as a well-defined withdrawal syndrome. There is also evidence that the residual effects of cannabis can last up to 24 hours. Significantly, the modern dose of cannabis is much more potent than in the past, when the majority of the research was conducted. As such, the reported adverse health effects may well be conservative. Although only a limited number of studies have examined the effects of cannabis on pilot performance, the results overall have been consistent.

Error Management Training - Defining best practice

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Error Management Training- Interview study to identify error management practices in experienced training captains

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Error Management Training - Simulator study to identify error management training in current practice

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This project investigated the use of weather radar displays in commercial aviation. Three studies are described.

The first study used an expertise model of the use of weather radar displays to classify aircraft accident and incident reports. The three data sources used were the Federal Aviation Administration Accident/Incident Data System, the National Transportation Safety Board Accident and Incident Database, and the Aviation Safety Reporting System. Although generalisation of the outcomes is limited, the results provide some evidence to suggest that where the use of weather radar was implicated in an aircraft accident or incident, the error was most likely to be associated with a failure to recognise and/or interpret the information on the display.

Study Two involved a cognitive interview of experienced commercial pilots and their use of weather radar displays to assist in the management of flight. The results revealed a relatively consistent response which emphasised the timely and accurate interpretation of radar 'paints' as the basis for successful performance. It was apparent that, for some pilots, the process involved the development and application of 'rules-of-thumb' and that these rules had been acquired through experience.

The results of Studies One and Two provided the basis for the development of a survey that was distributed to pilots both in hard-copy and on-line via the internet. Respondents were asked to provide information about their use of weather radar displays, describe an incident involving the use or misuse of weather radar displays, and give their interpretations of a series of 12 simulated weather radar 'paints'. In the case of the incidents described by the respondents, the results indicated that the majority of cases were related to the recognition and interpretation of the information on displays, consistent with the outcomes of Study One.

In relation to the simulated weather radar 'paints', the results indicated that while the interpretation of some of the displays was relatively consistent, the responses to other displays were less consistent between respondents. These differences were not due to demographic features such as age or experience but appeared due to the level of ambiguity associated with the displays. Specifically, for some displays, it appeared that the key cues necessary for the successful interpretation of the information were either difficult to interpret or were absent. This outcome forms the basis for a number of recommendations concerning improvements in training, education and the design of weather radar displays.

This report presents data concerning Australian aviation activity, the aviation industry, aviation accidents and incidents and highlights broad trends and developments in aviation safety. The data are presented graphically in time series figures. Data on aviation accidents and incidents were collected from the ATSB's aviation database. Data concerning aviation activity, the aviation industry, accidents and specific incident types were collected from three main sources: the Bureau of Transport and Regional Economics, part of the Department of Transport and Regional Services, the Civil Aviation Safety Authority and Airservices Australia.

The aim of this study was to provide information to the flying community about issues that have the potential to affect safety in the hope that increased knowledge and insight could lead to improved safety. The ATSB distributed the 'Aviation Industry Safety Survey' in November 2003 to 5,000 commercial pilots throughout Australia. Pilots were asked to respond to a series of questions regarding their flying experiences in the 12 months prior to receiving the survey. The survey consisted of two sections: Part A and Part B. Information about Part A has been reported in the ATSB Aviation Safety Survey - Safety Climate Factors (2004) publication. The analysis of one question (relating to common flying errors by respondents) in Part B was reported in the ATSB Aviation Safety Survey - Common Flying Errors (2004) publication. This report addressed six questions (39 to 44) in Part B of the survey (reproduced in Attachment A). Information concerning pilot age, highest licence held, hours flown, type of operation and aircraft details were obtained from the survey responses.

The twin-engine power loss accidents were analysed to identify the types of accidents that occurred. Ten of the 11 fatal accidents subsequent to a power loss in twin-engine aircraft were the result of an in-flight loss of control. In contrast, the majority of non-fatal accidents subsequent to a power loss were primarily the result of degraded aircraft performance and resulted in aircraft being forced landed. When a twin-engine aircraft sustains a loss of power, the resulting power output can produce a power condition that is either asymmetric or non-asymmetric. The twin-engine power loss accidents were grouped based on whether the aircraft was being powered asymmetrically or non-asymmetrically when the accident occurred.

Weather-related general aviation accidents remain one of the most significant causes for concern in aviation safety. Previous studies into the factors associated with weather-related general aviation occurrences have typically compared accident and non-accident cases. In contrast, this study does not concentrate on occurrence outcome. Instead, the emphasis is on the different behaviours that pilots exhibit in the face of adverse weather and, by inference, on the decision-making processes that underlie those behaviours. The work of this study is based on a set of 491 aviation accident and incident reports drawn from the Australian Transport Safety Bureau (ATSB) occurrence database. The study compares three groups of pilots who differed in their response to adverse weather conditions encountered during their flight.

Night Vision Goggles (NVGs) are binocular devices that enhance unaided night vision for pilots. Typically, NVGs are mounted on a pilot's helmet. This position enables pilots to look through the goggles outside the cockpit or under the goggles at flight instruments. By enabling the pilot to see in the dark, NVGs have the potential to improve the safety of visual flight at night. In most conditions, night vision goggles provide pilots with a significant increase in the quality of visual information compared with unaided night vision. They allow the pilot to see the horizon, objects, terrain and weather more easily. Furthermore, they assist the pilot to maintain spatial orientation, to avoid hazards such as inadvertent Instrument Meteorological Conditions (IMC) entry, and to visually navigate.