The status of commercial passenger operations in turbine powered single engine aeroplanes is presently under review by the civil aviation regulatory authorities of several nations. In this information paper BASI offers no argument for or against the introduction of such operations.

Present regulations on commercial passenger carriage were developed prior to the availability of the turboprop engines which are now in operation.

The Bureau of Air Safety Investigation recently conducted research into the rates of G onset and G levels experienced by a light aircraft pilot during normal aerobatics. The objective was to relate data obtained from the research to other data available from military authorities, in order to evaluate the possibility or otherwise of a light aircraft pilot sustaining G-induced loss of consciousness (G-LOC) during aerobatics.

MTAF procedures were introduced in Australia with the AMATS changes of 12 December 1991. The MTAF procedure applies at specified aerodromes. It depends on pilots making mandatory radio calls, hearing calls from other aircraft, assessing this traffic information for potential conflict, and responding appropriately with radio communication and avoiding action if necessary.

The MTAF procedure is designed to alert aircraft to all other air traffic in a designated area surrounding a particular aerodrome. The procedure mandates certain radio broadcasts and responses in these areas, and the pilots are then responsible for arranging their own separation.

In March 1993 BASI was informed that airline pilots had considerable concerns over the safety of RPT operations in MTAF areas. Reports stated that "Since the inception of MTAFs, [pilots] are experiencing conflict situations with unannounced, unalerted traffic, on a daily basis. This is resulting in numerous instances of immediate evasive action having to be initiated by aircraft operated within MTAFs".

This report was commissioned by the Bureau of Air Safety Investigation (BASI) to investigate the system of Notices to Airmen (NOTAM) following statements from some airline flight crews that current NOTAM presentation is not optimised to meet their needs. Pilots had stated that:

• Some NOTAM are not clearly written,
• The NOTAM format can be difficult to decipher,
• There is too much irrelevant information provided.

This information paper reviews the Bureau's policy on testing for drugs and alcohol, attempts to assess the prevalence of drugs and alcohol in aviation accidents and incidents, and discusses the adequacy of the present policy. The policies of Canada, the United Kingdom, and the United States are also outlined.

The carriage of traffic collision avoidance system (TCAS) equipment is not mandatory in Australian aircraft. However, many Australian and foreign registered aircraft operating in Australian controlled airspace are equipped with TCAS because of their compliance with a US requirement when operating in American airspace.

A total of 157 TCAS-related air safety occurrences were reported in Australian airspace during 1993 and 1994. The circumstances of these events, and the views of the pilots and air traffic controllers involved in the occurrences, were examined in detail.

Early versions of TCAS produced nuisance or unnecessary warnings, but later software has almost eliminated these problems. TCAS has had a positive safety benefit in Australia and is considered to be a valuable additional safety net in the Air Traffic Services system.

In June 1995, following a serious breakdown of separation between two passenger jets, BASI made a wide-ranging recommendation to the Civil Aviation Authority (CAA), calling for the fitment of airborne collision avoidance systems to all aircraft engaged in regular public transport (RPT) operations. In November 1996, the Civil Aviation Safety Authority (CASA) released a legislative instrument proposal dealing with the introduction of TCAS equipment to certain commercial transport aeroplanes.

On 24 December 1995 an Australian ibis was ingested into the engine of an Airbus A300 on take-off from Coolangatta Airport. The damage to the engine was extensive.

Bird strikes are a continual hazard for aircraft operations, particularly during the take-off and landing phases. The Bureau's database contains the birdstrike reports shown in appendix 1, tables IA, 1 B and 1 C for the years 1993, 1994 and 1995. It should be noted that the requirement for reporting birdstrike occurrences which did not involve aircraft damage was terminated in 1991. Prior to 1991 all bird-strike occurrences were reported to the Bureau and forwarded to the Civil Aviation Authority's Bird Hazard Investigation Unit.

The regional airline industry is an integral part of the Australian air transport system, and is particularly important in rural and remote areas. The industry has a major role in supplementing the high capacity airlines and providing feeder services into the capital cities.

The accident rate for regional airlines has remained relatively stable since 1990, although it is higher than the rate for high capacity air transport.

Partly as a result of a small number of highly publicised fatal accidents involving regional airlines, there has been considerable debate about safety standards within this sector of the industry both in Australia and overseas. BASI believes that there are opportunities for improving the safety levels of regional airlines through the identification of safety issues before they result in serious incidents or accidents.

Discussions with industry personnel have highlighted a range of issues which they believe need attention. This preliminary report outlines the issues raised.

During 1992 and 1993 there was an increase in the frequency of reported occurrences involving co-ordination between Australian and Indonesian ATS. Although some involved aircraft travelling from Australia to Indonesia, the majority (92%) involved aircraft travelling from Indonesian airspace into the Australian FIR.

The CAA Australia and the Indonesia Directorate General of Air Communications are signatories on a LOA between the two countries. This LOA supplements ICAO documents in respect to separation standards and co-ordination procedures and is - updated periodically. The latest update was on 18 December 1993 (see Appendix 1).

The CAA have sent a series of delegations to Indonesia to liaise with their ATS authorities. These visits have included several briefing sessions to all levels of Indonesian ATS from the Director Aviation Safety to operational controllers. Specific attention has been paid to boundary conflict situations and the importance of correct and timely co-ordination, all of which are covered in the LOA. In August 1992, a major visit to the Indonesia was undertaken by CAA staff which resulted in 16 recommendations and 10 observations (see Appendix 2). These were accepted by the Indonesian authorities. In December 1993 another visit took place involving CAA supervisory field staff, managers and representatives of the CAA Quality Assurance section.

Maintenance constitutes a significant and rising cost to the airline industry. In the USA, maintenance costs are increasing as a proportion of airline operating costs. In 1989 maintenance constituted 11-8% of US airline operating costs or greater than US$8 billion per year (Shepherd 1991). The annual cost to the Australian airline industry is likely to be in the order of A$500 million per year.