At approximately 1405 Eastern Standard Time on 15 August 2007, an Airbus Industrie A330-300 aircraft, registered PK-GPF, was about 926 km north-west of Sydney, NSW enroute to Denpasar, Indonesia when the right (No-2) engine low oil pressure warning activated. The flight crew shut down the engine and commenced a descent to flight level 240 while they advised air traffic control (ATC) of the event and requested a clearance to return to Sydney. Air traffic control cleared the crew to descend and to track directly to Sydney.

After landing, the operator's contracted maintenance staff inspected the No-2 engine, a Rolls-Royce RB211-Trent 700 series. They found that oil was leaking from the braided section of the flexible oil pressure tube that supplied oil to the oil pressure transmitter for that engine.

The Australian Transport Safety Bureau (ATSB) inspected the oil pressure tube in conjunction with the UK Air Accidents Investigation Branch and the engine manufacturer. That inspection revealed that the tube had fractured, probably due to high cycle fatigue in a stress concentration area.

The aircraft operator has since commenced a modification program on all of its Airbus A330 aircraft to fit an additional retainer bracket and associated hardware to the flexible oil pressure transmitter tube in an effort to prevent similar occurrences.

On 13 August 2007, a Boeing 737-700 aircraft, registered VH-VBR, was operating on a scheduled flight from Brisbane to Hamilton Island, Qld. On reaching cruise altitude, the flight crew became aware of a fuel imbalance situation due to fuel loss from the number 2 (right) engine. At 1311 Eastern Standard Time and approximately 148 km SE of Rockhampton, Qld, the crew conducted an in-flight shut down of the right engine. The aircraft was subsequently diverted to Rockhampton where a single-engine approach and landing was completed without further incident.

Examination identified the leak as being from the main fuel return pipe where it connected into the oil/fuel heat exchanger. The pipe connection was of flanged plate design, held in position by four bolts tightened into threaded inserts on the oil/fuel heat exchanger body. The threaded inserts had failed, pulling free of the heat exchanger body.

The investigation found that the failure of the inserts was the result of over tightening that had occurred during previous maintenance. The oil/fuel heat exchanger was subject to two different modification states, each requiring different fuel return pipe bolt torque values.

As a result of this occurrence, the aircraft operator notified the subsequent maintenance provider of the incident and received assurance that their process, procedures and oversight were adequate to prevent a recurrence.

On 5 August 2007 at 1407 Eastern Standard Time, a Saab Aircraft AB 340B, registered VH-RXX, was being operated on a scheduled passenger service from Sydney to Albury, NSW. It was the aircraft's first flight of the day and the first flight after a routine compressor wash carried out on the engines.

An odour, which had been apparent inside the aircraft during the preflight procedure and taxi, and which was described as 'similar to curry', became much stronger from just before rotation until about two minutes after take-off. Believing the fumes were caused by compressor wash fluid and would dissipate, the flight crew elected to continue the flight.

The manufacturer of the compressor wash fluid confirmed that, when heated, it would produce an odour similar to curry.

The operator reported that their compressor wash procedure had been followed and was unable to explain the subsequent ingress of fumes to the cockpit and cabin of the aircraft.

On 7 August 2007, a British Aerospace (BAe) 146 aircraft, registered VH-NJT, was holding at the Instrument Flight Reporting point, ROTAP, 95 NM (176 km) north-east of Perth, WA. At 0950 Western Standard Time, the left side inner 'Feed Tank Low Level' warning light illuminated, followed almost immediately by the right side inner 'Feed Tank Low Level' warning light.

A PAN PAN radio broadcast was made to Air Traffic Services (ATS) and the aircraft landed at Perth 26 minutes later without further incident. The crew reported that, after landing, a total of 1,920 kgs of fuel remained on board.

Maintenance inspections carried out by the operator found no faults with the aircraft fuel system. The operator advised that 2 days later, a fault was reported in the left side inner boost fuel pump. The pump was replaced, and no further faults have been reported with the aircraft fuel system.

Preliminary report released 12 October 2007

On 31 July 2007, a Rockwell Commander 500S, with a pilot and passenger on board, was making a night, instrument flight rules, business flight from Essendon Airport, Vic. to Shepparton. While cruising at 7,000 ft and approximately 25 NM (46 km) north-north-east of Essendon, the aircraft disappeared from radar. Attempts by the controller to contact the pilot were unsuccessful. Later that night the aircraft wreckage was found in timbered ranges near the last radar position. There were no survivors.

Wreckage was distributed over a considerable area and the outer wing sections and the tail had separated in flight. Subsequent wreckage reconstruction and examination of the fracture surfaces found no evidence of contributory fatigue cracking, pre-existing defects or structural corrosion.

At the time of the occurrence there was a north to north-westerly wind of 40 kts or greater in the area. The Bureau of Meteorology had issued two concurrent SIGMET warnings for the period of the flight. The first warned of severe mechanical turbulence over and south of the ranges, and the second warned of occasional severe mountain wave turbulence.

The Preliminary report contains factual information that has been obtained for the investigation to date and describes the focus of further investigations.

On 22 July 2007, the crew of a Bell 412 helicopter was conducting a night approach as part of a search for the source of transmissions from an emergency locator beacon. During the approach to a landing site, the pilot of the helicopter lost situational awareness and allowed the forward speed of the helicopter to decrease to zero. The helicopter developed a high rate of descent and, during an attempt to arrest the rate of descent, the helicopter was subjected to an over-torque condition. The Australian Transport Safety Bureau did not conduct an onsite investigation into the occurrence. However, the operator's internal investigation identified a number of safety issues. Following the investigation, the operator took safety actions to address the identified issues.

Preliminary report released 11 September 2007

On 24 July 2007 at 1500 Central Standard Time, a Robinson R22 Beta helicopter, registered VH VHQ, with the pilot the sole occupant, departed from a helipad at Maryfield Station, NT, in order to recommence cattle mustering activities. Visitors to the station, who had recently been given scenic rides in the helicopter, were still in the general area of the helipad at that time.

During the initial climb after take-off, and at a height of about the tops of the surrounding trees, the helicopter's 'low RPM' warning horn activated. During the recovery manoeuvre by the pilot, one of the visitors was struck in the head by the helicopter's main rotor and was fatally injured. The pilot immediately landed the helicopter.

At approximately 1944 Coordinated Universal Time on 23 July 2007, an Airbus Industrie A330- 202 aircraft, registered VH-EBE, was about 4 hours into its flight from Bangkok, Thailand to Melbourne, Australia, when the left (No-1) engine had an uncommanded shutdown.

The flight crew attempted unsuccessfully to restart the engine and subsequently diverted to Denpasar Airport, Indonesia. The operator's maintenance staff inspected the aircraft and performed a series of tests and examinations, which revealed that the engine electronic control unit (ECU) for the No-1 engine had malfunctioned.

The defective ECU was sent to the component manufacturer for a detailed inspection. That inspection found a short circuit in the input output module (IOM) circuit board that developed from a microscopic air void in the insulation compound of the circuit board layers.

As a result of this incident, the aircraft operator replaced the ECUs in a number of aircraft, and the board manufacturer amended its production standards and procedures.

On 29 August 2007, a SAAB Aircraft Company 340B-229 (SAAB) aircraft was being operated on a scheduled passenger service from Adelaide, SA to Mount Gambier. The aircraft departed from runway 05 soon after an Airbus A320-232 (Airbus) aircraft departed from the same runway. When the SAAB reached a height of 250 to 350 ft above ground level (AGL), the flight crew experienced abrupt, severe buffeting and an uncommanded roll to the left, followed by another roll to the right.

As a result of this occurrence, the aircraft operator advised that they reviewed their operating procedures relating to departures behind jet aircraft and will use the ATSB report as part of a safety promotion strategy directed at all company pilots. In addition, The Civil Aviation Safety Authority is reviewing the safety implications of this incident and is considering the development of a safety education program for flight crew and air traffic controllers.

On 25 July 2007, a twin-engine Cessna 441 (Conquest II) aircraft carrying three passengers was being operated on a scheduled passenger flight from Port Augusta to Adelaide, SA. At 1035 Central Standard Time, while cruising at flight level 210, the aircraft's right engine failed suddenly approximately 23 km north of Ardrossan, SA.

When the failed right Garrett TPE331-8 turboprop engine was removed from the aircraft and subsequently disassembled, it was revealed that the compressor bearing at the front end of the engine had catastrophically failed. That bearing provided both axial and lateral support for the turbine section. Once that support was lost, the engine's rotating turbine section shifted forward under the influence of thrust loads, resulting in rotor-to-case contact and rapid engine failure.

The aircraft had been inspected two months prior to the engine failure for a suspected lightning strike, however the inspection did not reveal any obvious electrical damage at that time. Considerable levels of residual magnetism were found within the compressor bearing and other engine components during the ATSB examination. Such levels indicated that direct electrical current (DC) from an aircraft lightning strike had passed through the engine during service. The passage of such currents resulted in undetected electrical damage and led to the eventual failure of the compressor bearing.