Mountain wave and associated turbulence In Australia, mountain waves are commonly experienced over and to the lee of mountain ranges in the south-east of the continent. They often appear in the strong westerly wind flows on the east coast in late winter and early spring. Mountain waves are a different phenomena to the mechanical turbulence found in the lee of mountain ranges, and can exist as a smooth undulating airflow or may contain clear air turbulence in the form of breaking waves and 'rotors'. Mountain waves are defined as 'severe' when the associated downdrafts exceed 600 ft/min and/or…

The determination of blood ethanol concentration in a deceased pilot is an important part of the accident investigation. The finding of an elevated blood alcohol level in such a case may have significant implications, both medico-legal and social. It is therefore important to ensure that the finding of an elevated blood alcohol concentration is valid. It is known that micro-organisms involved in the process of putrefaction after death can produce alcohol, usually a mixture of ethanol and other volatile substances. This process occurs when a body is not refrigerated soon after death and is…

Diabetes mellitus is a disease with a wide spectrum of severity and many potential complications if inadequately treated. Historically, diabetic pilots have been permanently disqualified from flying duties. This policy was based on the increased risk of sudden incapacitation in-flight due to hypoglycaemia and cardiovascular disease in diabetics. In recent decades, a shift in worldwide aeromedical policy has occurred. This has resulted in diabetic pilots in several countries, including the United States and Australia, being granted limited flying certification. These pilots are required to…

An examination of the Australian Transport Safety Bureau's aviation occurrence database indicates that distraction has contributed to a number of aviation safety accidents and incidents. The purpose of this study was to: (i) examine the characteristics of pilot distraction(ii) explore the range of distraction sources that have contributed to aviation safety occurrences, and(iii) develop a taxonomy of pilot distraction. In total, 325 occurrences were identified using the database. The results showed that the majority of occurrences were incidents rather than accidents or serious incidents.…

Boeing 747-438, VH-OJU EXECUTIVE SUMMARY An Australian registered Boeing 747-438 aircraft operating a regular passenger transport flight sustained the failure of an engine shortly after take-off from Los Angeles, USA. The engine was subsequently shutdown and the aircraft returned for an uneventful landing. The failed engine was a Rolls Royce RB211-524G2-T model. Preliminary inspection by the operator's maintenance personnel found evidence of extensive internal mechanical damage within the high-pressure compressor section of the engine and as a result, returned the engine to Australia for…

In 2004, there were two wirestrike accidents in New South Wales involving helicopters undertaking locust control operations. The first accident occurred in October 2004 near Forbes and resulted in minor injuries to one occupant and extensive damage to the helicopter. The second accident occurred in November 2004 near Dunedoo and resulted in the death of two occupants. A third occupant was seriously injured and there was extensive damage to the helicopter. A third accident, near Mudgee in November 2004, involved a helicopter that was being used for locust control, although the helicopter was…

There has been a long standing interest among various transport safety organisations, researchers, other stakeholders and the public concerning the relative safety of various transport modes. Questions are often posed along the lines: on average, is travel in a light aircraft safer than a typical journey in a private car? or - what is the safety difference between motorcycle riding and driving a car? Consideration of relative transport safety risks also has potentially important policy implications, particularly where contingent resource allocation or risk management decisions are involved.…

The ATSB Annual Review documents ATSB's achievements and safety activities from 1 July 2004 to 30 June 2005 and outlines its business planning for 2005-2006. Executive Directors message In 2004-05 the ATSB benefited considerably from the funding boost for aviation investigations and aviation database replacement that was provided in the May 2004 Federal Budget. During the year, the Bureau recruited and commenced training 12 extra aviation safety investigators, instigated 109 aviation occurrence investigations and released 98 aviation investigation reports, up from around 60 in recent years.…

Recorded voice data, such as from cockpit voice recorders (CVRs) or air traffic control tapes, can be an important source of evidence for accident investigation, as well as for human factors research. However, most of the analysis has been based on subjective interpretation rather than the use of systematic methods, particularly when dealing with the analysis of crew interactions. Conversation analysis uses highly detailed and revealing transcriptions of recorded voice (or video) data that can allow deeper analyses of how people interact. When analysing recorded voice data, and especially for…

Boeing Commercial Aircraft Group, 747-436, G-BNLK 1. FACTUAL INFORMATION 1.1. Examination brief The disassembled components of an electric air-cooling fan (figure 1) were received by the ATSB Technical Analysis unit for examination and analysis of the damaged fan impeller. The fan unit had been fitted to a Boeing 747 aircraft (registration G-BNLK) to provide forced air circulation for a forward galley chiller unit. During the early stages of a flight on 10 August 2002, a small fire developed in the forward cargo compartment adjacent to this unit (figure 2). Physical and recorded evidence…