Communication within the air traffic system relies heavily on the verbal interaction between pilots and air traffic controllers (controllers) to ensure the safe and efficient operation of air traffic. The use of standard phraseology and radio telephony procedures, such as readbacks, minimises the opportunity for misinterpretation between pilot and controller.

Some sectors of the industry have raised concerns regarding the use of excess or non-standard phraseology in readbacks on the surface movement control (SMC) frequency, resulting in radio congestion. The purpose of this report was to explore the relationship between excess or nonstandard words in readbacks and its effect on frequency congestion.

A review of the Sydney SMC frequency tapes concluded that most users complied with the readback requirements stipulated in the Aeronautical Information Publication (AIP), with only the occasional radio transmission containing excess or non-standard verbiage. Overall, the tapes identified a high level of compliance with the AIP readback requirements; however, it was noted that the use of pleasantries was commonplace. While these did not appear to affect frequency congestion adversely, in times of high traffic density it seems inappropriate.

This study provides a systematic analysis of the types of human error occurring in Australian civil aviation accidents. It also compares these results against a larger sample of accidents occurring in the United States. Inevitably, all humans make errors. But safety can be enhanced when the number and consequences of these errors are reduced. This paper aims to enhance aviation safety through extending our knowledge of aircrew errors.

While the types of accidents and flying operations varied slightly between Australia and the US, the pattern of aircrew errors were remarkably similar. Skill-based errors were the most prevalent type of aircrew unsafe act, followed by decision errors, violations and perceptual errors in both Australian and US accidents. Skill-based errors were also the most common error type irrespective of the severity of the accident. In Australia, decision errors and violations were more common in fatal accidents.

The trend data indicated that the proportion of accidents associated with skill-based errors did not change over the period studied, but decision errors decreased.

The distribution of unsafe acts across flying operation type indicated that skill-based errors were disproportionately higher in both general aviation and agricultural operations. Charter operations (called on-demand in the US) had a high proportion of violations and decision errors. The pattern of unsafe acts within each type of flying operation was broadly similar for Australian and US accidents.

The study demonstrated that the greatest gains in reducing aviation accidents could be achieved by reducing skill-based errors. Moreover, improvements in aeronautical decision making and the modification of risk-taking behaviour could reduce aviation fatalities. Further study is needed to both identify which particular skills need improving, and to investigate the importance of interactions between the error categories.

Following three breakdown of separation occurrences in the airspace of the Sydney Terminal Area (TMA), the Bureau of Air Safety Investigation (BASI) initiated a systemic investigation into the common factors underlying those occurrences. The investigation commenced on 22 June 1998 and was completed by 31 July 1998. Three further occurrences were identified during the course of the investigation.

The systemic investigation has identified safety deficiencies primarily related to the management of change, and the rate and complexity of change faced by air traffic controllers operating in the Sydney Terminal Control Unit over the last four years. Resolving these management issues will further enhance the safe operation of aircraft in the airspace of the Sydney Terminal area. This report contains nine safety recommendations that have been developed to address identified safety deficiencies.

The Robinson R22 helicopter is the most common model of rotary-wing aircraft on the Australian register and has been a popular choice for private operations, flying training and various types of aerial work activity. The R22 has a relatively good safety record compared with other light piston-engine helicopters in Australia based on activity levels.

The R22 is also the favoured type for aerial stock mustering operations - a uniquely Australian application that supports the local beef cattle industry. Despite its popularity in this type of work, little was known about the helicopter's suitability for the task. Like other helicopters on the Australian register, the R22 received its initial airworthiness certification in its country of manufacture (United States). The spectrum of manoeuvres conducted in aerial stock mustering did not form part of the flight profile used when the helicopter type received its certification.

In 2004 the ATSB commissioned AeroStructures, an Australian engineering company, to undertake a study of forces acting on an R22 engaged in aerial mustering operations. AeroStructures Report:

Their study offers some useful data on R22 flight profiles in aerial mustering operations, and compares these with the flight profiles used by Robinson Helicopter Company when the helicopter was initially certified.

The AeroStructures testing showed that mustering operations can involve large and sudden power changes that apply very high loads on the helicopter's drive system, and these may exceed the limits set during the certification process. Their report highlights the importance of handling technique, and especially good engine management.

This aim of the study was to provide objective data to inform fatigue risk-management processes by determining the quantity and quality of sleep obtained by airline pilots during transcontinental back of clock operations, and any changes to subjective fatigue and neurobehavioral performance during these sectors. Typical transcontinental back of clock route pairings involve a departure close to midnight Perth local time, with a dawn arrival into an East-coast city such as Melbourne, Sydney or Brisbane. In many instances this first sector is followed by a second sector to another east-coast destination, with sign-off at approximately 0900 Eastern Standard Time. Data were collected by participants during a two-week period of a normal rostered flying for an airline. During each of the 14 days of data collection, participants were required to undertake the following:

1. Wear an activity monitor wristwatch 7 days prior to, and 6 days after, a transcontinental back of clock flight;
2. complete sleep and duty diaries, which record time of sleep, subjective alertness, and time of duty; and
3. complete a simple 5-minute Psychomotor Vigilance Task (reaction time task) during the cruise of each sector, and three times on non-flying days.

The results of this study suggest that Australian transcontinental back of clock operations, as operated by the airline involved in this study, differed significantly from a baseline sample of daytime duty periods in a number of important areas with respect to prior sleep, neurobehavioral performance, and subjective fatigue. While there were some significant differences in sleep and subjective fatigue as a function of a single transcontinental sector of back of clock flying, these differences were, on average, of a magnitude that was unlikely to impact on flight crew performance and overall safety. However, when a primary transcontinental sector is followed by an additional east-coast sector, there is evidence of reduced prior sleep, impaired neurobehavioral performance, and high levels of subjective fatigue.

Each year the United States' Aircraft Owner's and Pilots Association (AOPA) Air Safety Foundation releases a report summarising the accident trends and factors for general aviation (GA) for the previous calendar year. The Nall Report has established itself as one of the aviation community's benchmark reports and its release is anticipated across the industry. The report provides essential data in an easy-to-read format, giving a broad overview of the state of general aviation and safety trends in the US.

As part of the Australian Transport Safety Bureau's (ATSB) mission to enhance public awareness of aviation safety, the Australian Aviation Safety in Review - 2007 has been developed to provide a readily accessible analysis of the Australian aviation sector, with a strong focus on safety trends. Unlike the Nall Report, this publication covers all major categories of aircraft operations, from Regular Public Transport (RPT) to general aviation, and even some information about sports aviation.

Additionally, some demographic data on Australian aviation is provided in order to measure the levels of aviation activity in Australia, and provide a context within which to examine the accident trends. Accident rates are presented both in terms of the number of accidents and as rates per 100,000 hours, to enable comparison between operational categories. The latest year for which flying hours are available is 2005. Accordingly, this inaugural edition of the Australian Aviation Safety in Review - 2007 covers the calendar years 2001 to 2005, offering insights and information about key trends and emerging issues.

The ATSB intends to release this report on a regular basis as a means of informing both the aviation community and the wider public about Australian aviation accident and activity trends.

Regional airline operations globally have expanded over the past decade for various reasons, including filling gaps left by legacy carriers who have reduced services on unprofitable routes, opportunities provided through other cost based market rationalisations, and the introduction of new and more capable regional type aircraft. Very little formal research has been done in Australia or overseas to assist with the development of safety models and tools for regional airline operations. Regional Express (REX) is a relatively new airline that was created by merging two separate and culturally different airline entities. After a post start-up initial settling in period, REX needed a new tool to further develop safety-based auditing for its newly combined flight operations department. The Line Operations Safety Audit (LOSA) offered through the University of Texas LOSA Collaborative, provided an effective tool for this purpose. Around the time REX was reviewing its need in this area, the LOSA Collaborative was confirming an interest in conducting research with regional airlines. The LOSA Collaborative wished to obtain data from regional airlines to add to its LOSA Archive database in order to move toward making the database more representative and the LOSA tools more relevant for use in the regional airline environment. The LOSA Collaborative set out to attract three regional airline participants to add their data through the LOSA process. Regional Express was successful in attracting funding under the Australian Transport Safety Bureaus Aviation Safety Research Grants Program to undertake the LOSA process. Completion of this project has added to the expansion of the LOSA database to include regional airline data. This report describes the LOSA process as it applies within the regional airline context of REX and the reported outcome types specific to the LOSA methodology, process, and tools. Regional Express is one of the first regional airlines globally to participate in a LOSA program.

Maintenance incidents contribute to a significant proportion of worldwide commercial jet accidents, yet until recently, little was known of the nature of maintenance incidents and the factors which promote them.

In face-to-face interviews, maintenance technicians were asked to report examples of maintenance incidents which they had experienced first-hand. Eighty-six incident reports were recorded.

Human factors were involved in most of the reported incidents, with workers on duty between the hours of 0200 and 0400 having a greater chance of having an incident than workers on duty at other times of the 24-hour clock. The frequency of incidents increased as the shift progressed up to the second-last hour, after which the frequency of incidents diminished.

For those incidents which had the potential to affect the airworthiness of an aircraft, difficulties with procedures emerged as the most significant factor. This included misunderstandings and ignorance of procedures.

For those incidents which had the potential to affect the health and safety of workers, difficulties with tools and equipment emerged as the most frequent factor.

The majority of the human errors involved in incidents were rule-based mistakes, many related to mistaken assumptions. Absent-minded slips and lapses were involved in approximately one-third of the incidents.

The final section of the report contains suggested safety actions, intended firstly to reduce the frequency of human error and maintenance incidents and secondly, to reduce the consequences of any such errors which do occur.

Human error is recognised as an important issue in fields as diverse as medicine, mining and shipping, and to some extent aviation.

Although the human element has long been recognised as important in the cockpit, its role in aircraft maintenance has been largely overlooked.

According to Boeing figures 12% of major aircraft accidents involve maintenance, and 50% of flight delays in the US are caused by maintenance errors.

In response to a worldwide lack of information on the issue, in late 1998 the Bureau distributed a safety survey to all licensed aircraft maintenance engineers in Australia.

This survey was the first such study undertaken anywhere in the world.

In addition to collecting incident reports, part of the survey used a technique pioneered by road safety researchers in the UK, where recipients were asked to report minor errors and shortcuts.

The focus was on learning how common these events are relative to one another, rather than obtaining precise event frequency information. In that regard there was no specific time frame specified in the survey form in which the event could have occurred.

Most of the errors reported by the respondents constitute 'near misses'. However, it is possible to anticipate how more serious events could occur by gathering this information.

The ATSB considers that the issues identified in the survey are not specific to Australia but will be of use to safety agencies around the world.

Based on early information from the survey the Bureau previously published in Asia-Pacific Air Safety articles that identified a number of recommendations:

1. the need for refresher training for aircraft maintenance engineers
2. the need to remove barriers which discourage aircraft maintenance engineers from reporting incidents
3. the need for fatigue management programs
4. human factors training for management and engineers, and
5. minimisation of the simultaneous disturbance of multiple or parallel systems, such as both engines on twin-engine aircraft.

The recent article on the survey on the ATSB Supplement to Flight Safety Australia March-April 2000 also included advice directed to aircraft maintenance engineers concerning memory lapses, pressure, fatigue and coordination difficulties.

The survey is part of a broader study of aircraft maintenance operations, which is anticipated, will lead to identification of targeted safety measures.

The ATSB has come a long way since its creation on 1 July 1999. Legislation, training and IT systems have all been upgraded. The ATSB has an increasingly national and international reputation for independent safety material. This is reflected in the almost 800,000 new visitors to the ATSB website which also had more than 30 million 'hits' in 200607, and in multiple articles in such publications as the prestigious US-based Flight Safety Foundations AeroSafety World.

During 2006 - 07, the ATSB finalised its complex investigation into Australian civil aviation's worst accident since 1968, the 15-fatality aircraft accident near Lockhart River, Queensland on 7 May 2005. The 500-page final report released on 4 April 2007 identifies important safety issues to enhance future aviation safety relating to the crew, the operator, regulatory oversight and instrument approach chart design. Three ATSB factual reports, a research report and ten safety recommendations were released during the course of the almost two-year investigation. A further ten safety recommendations were issued with the final report, which also utilised an enhanced ATSB investigation and analysis methodology. Among other coronial inquests, the ATSB assisted with the inquest into the Lockhart River accident by the Queensland State Coroner which included a month of hearings on Thursday Island and in Brisbane. The Coroner reported on 17 August 2007.

During the year the Bureau released 80 final aviation investigation reports, 19 aviation safety recommendations, 10 aviation safety research reports and five research grant reports. The ATSB also cooperated with the Indonesian National Transportation Safety Committee (NTSC) in the investigation of the Garuda Airlines Boeing 737-400 accident at Yogyakarta Airport on 7 March 2007 in which 21 died, including five Australians, and 12 were seriously injured. ATSB assistance included an on-site team comprising a Deputy Director and two senior investigators, flight recorder analysis in Canberra, and the drafting of preliminary and final reports.

In April 2007 the Bureau introduced a new Safety Investigation Information Management System (SIIMS) aviation database which will be extended to rail and marine in 2007-08. SIIMS was developed using the $6.1 million committed by the Australian Government in the May 2004 Budget, and was within time and budget.

In marine, the ATSB released 14 investigation reports, issued 38 safety recommendations and continued an education campaign on commercial fishing vessel safety. International success included ATSB coordination and facilitation of recent amendments to the Code for Investigation of Marine Casualties and Incidents as a member of the IMO Flag State Implementation Subcommittee. The ATSB also assisted with the inquest into the loss of the Immigration vessel Malu Sara with five fatalities in the Torres Strait.

The ATSBs rail safety investigation team released nine final reports and 39 safety recommendations under the Transport Safety Investigation Act 2003 (TSI) which included a number of level crossing accidents. In June 2007, the ATSB published jurisdiction regulators rail safety occurrence data in eight key categories covering the period January 2001 to December 2006. Further improvements in rail safety data are being sought through a process coordinated by the National Transport Commission.

The ATSB is continuing its commitment to training its investigators through accredited Diploma of Transport Safety Investigation. In 200607, 12 staff completed the TSI Diploma with 13 progressing through the required coursework and mentoring.

In March 2007 I completed my term as Chairman of the International Transportation Safety Association (ITSA), which includes major independent transport safety investigation bodies from around the world. ITSA has been revitalised and has grown to include the UK, Japan and Norway. France and South Korea are potential new members.

The ATSB continued to support Ministers with road safety advice and coordinated with other jurisdictions to develop the National Road Safety Action Plan for 2007 and 2008, which was approved by Ministers of the Australian Transport Council. While the challenges in road safety are immense, progress is being made in jurisdictions and through other stakeholders. It has been my privilege to chair the National Road Safety Strategy Panel since 1999 and work with such dedicated officers as ATSB General Manager Joe Motha and Team Leader John Goldsworthy and senior staff including Chris Brooks.

In 2006-07 the ATSB released 25 road safety research and statistical publications including a report on transport injuries amongst Indigenous people. The Bureau also helped organise an Indigenous road safety forum in October 2006. Work continued in preparation for the major novice driver research trial in New South Wales and Victoria which the Australian Government is supporting. Partners are scheduled to finalise the curriculum and conduct pilot testing before the end of 2007.

All of the achievements made in 2006-07 and on an ongoing basis are the result of the dedication of ATSB professional officers. For this untiring service, I salute them all. Most have made major personal sacrifices to make a difference for future transport safety. I particularly recognise my direct report colleagues: Peter Foley, Kerryn Macaulay, Joe Motha, Alan Stray and Julian Walsh. The investigator-in-charge of the Lockhart River investigation, Greg Madden and his team also deserve special praise.