Key points

• Engine surge and power loss occurred due to damage caused by replaceable screwdriver tip being left in the engine during maintenance;
• Tool control is an important part of aircraft maintenance, even for seemingly insignificant components;
• Incident is a reminder that engine failures can create unusual sounds and vibrations that can’t be easily replicated in simulator training.

An engine power loss and rejected take-off incident involving an Airbus A320 at Brisbane Airport occurred after a screwdriver tip was left inside the engine during maintenance, an Australian Transport Safety Bureau investigation notes.

On 23 October 2020, the Jetstar Airways operated A320 was departing on a scheduled passenger flight from Brisbane to Cairns.

As power was being applied for take-off, the crew felt a vibration and heard a popping noise, which rapidly grew faster and louder. At the same time, the aircraft diverged to the right of the runway centreline despite the first officer applying full left rudder pedal.

The captain immediately selected reverse thrust and brought the aircraft to a stop.

Some of the passengers onboard the aircraft, a Brisbane tower air traffic controller, and flight crew of a following aircraft reported momentarily seeing flames coming out of the right engine.

The aircraft was taxied back to the airport gate, and all passengers and crew disembarked safely.

Engineers then reported finding metallic debris in the tailpipe of the aircraft’s right engine. On disassembly, it was discovered the engine’s high-pressure compressor had sustained significant damage. A removable screwdriver tip was found in the engine’s combustion section.

The ATSB’s investigation determined the screwdriver tip had been in the engine for over 100 flights.

“The ATSB concluded the tool bit had been left in the engine after maintenance and when the engine was running, it entered the high-pressure compressor, leaving dents and nicks in numerous rotor blades and stator vanes,” said ATSB Director Transport Safety Stuart Macleod.

“At least two of these dents and nicks initiated fatigue cracks, which developed during the aircraft’s subsequent operation, and led to a blade failing during the incident flight’s take-off roll.”

The liberated blade then caused greater damage to the engine’s high pressure compressor, and the engine surged, resulting in the loss of power and the low-speed rejected take-off, said Mr Macleod.

“Tool control is an important part of maintenance processes. Small and seemingly insignificant tool components can, and have, caused significant incidents or accidents.”

Mr Macleod said the incident was also a good example of why flight crews need to be aware that the noise and vibration from an actual engine failure may be greater than, or different to, that experienced during simulator training.

“High-fidelity training devices like full motion flight simulators aim to maximise the realism of an artificial environment, but there is a limit to their ability to replicate extreme events.”

Read the final report: Engine power loss and low speed rejected take-off involving Airbus A320-232, VH-VFF, Brisbane Airport, Queensland, on 23 October 2020

Key points:

• A driver was fatally injured when their car collided with an express passenger train at the Kianawah Road level crossing;
• The design of the level crossing did not meet the Australian Standard. The boom barrier did not extend to the edge of the painted median traffic island, leaving a 3.1 metre gap;
• At the time of the accident there was no formal interface agreement to manage risk at the level crossing between the rail operator and the road manager.

Risk assessment and assurance processes are among the areas of focus of the Australian Transport Safety Bureau’s on-going investigation into a collision between a car and an express passenger train at a Brisbane level crossing earlier this year in which the car driver was fatally injured.

An ATSB preliminary report detailing factual information from the investigation’s early evidence collection phase notes that at around 1330 on Friday, 26 February 2021, the driver of a small four-door hatchback had left their friend’s address in Brisbane, to drive to Wynnum.

Approaching Lindum station in West Wynnum, the hatchback travelled in an easterly direction along Lindum Road, which runs roughly parallel with the Cleveland line railway before reaching a T-intersection with North Road, part of a large junction which incorporates the Kianawah Road level crossing.

The driver’s friend stated the driver, who was a resident of the Sunshine Coast, was unfamiliar with the area, and it was likely they were using a GPS navigation system.

Approaching the T-intersection, the driver’s intention was to turn right, pass through the level crossing, then turn left down Sibley Road, on the other side of the railway.

Two cars were already waiting at the stop line, also to turn right. The first turned and passed through the crossing during a pause in traffic.

At that time, around 1340, a Queensland Rail (QR) express train, travelling in an easterly direction towards Cleveland, automatically activated the level crossing protection on its approach.

The second car ahead of the hatchback turned right as the crossing’s lights were flashing, and crossed the railway as the boom gates were already lowering.

The driver of the hatchback then had to pause and give way to two other vehicles turning off North Road into Lindum Road.

The driver of the second of these vehicles observed the boom barrier was horizontal and saw a train approaching as they turned. After turning, they noticed in their rear-vision mirrors the hatchback had moved off and was approaching the crossing. They witnessed the car pass onto the level crossing and collide with the train.

CCTV footage from Lindum station showed the hatchback passed to the right of the boom barrier’s lowered arm, but to the left of the faded dotted turn guideline.

The hatchback was destroyed, and the driver, the sole occupant, was fatally injured. The train sustained minor damage and the only two occupants, the driver and guard, were not injured.

A Queensland Police Service post-accident assessment of the level crossing identified the boom barrier passed by the hatchback did not extend to the edge of the painted median island, the preliminary report notes.

The relevant Australian Standard for boom barrier design states that boom barriers shall extend to the dividing line or centre of a roadway. However, the gap between the edge of the median island and the tip of the boom barrier when lowered was 3.1 metres.

The CCTV footage showed that the boom was lowered for about 10 seconds before the hatchback passed on to the crossing.

“The ATSB is continuing to examine the risk assessments conducted for this level crossing, and the processes used for those risk assessments,” said ATSB Acting Chief Commissioner Colin McNamara.

“The investigation will also assess the assurance activities conducted by the rail infrastructure manager and the road manager relevant to risk at level crossings, including the development of an interface agreement.”

QR, the rail infrastructure manager, advised the ATSB that prior to the accident the last assessment of the Kianawah Road level crossing under the national Australian Level Crossing Assessment Model was conducted in 2002.

Separately, the preliminary report notes that Rail Safety National Law legislation requires an interface agreement between the rail infrastructure manager and the road manager be in place to outline the shared responsibility for safe railway operations at level crossings.

While this requirement had come into place in Queensland in 2012, no interface agreement had been formalised at the time of the accident.

QR has advised the ATSB that it has since formalised an interface agreement with Brisbane City Council encompassing all level crossings within the council area. Further, QR has commenced engineering activities to source and trial usage of a longer boom barrier for the northern side of the Kianawah Road level crossing. 

The rail operator and the council are also participating in the Lindum Station Precinct Study, which was initiated by the Department of Transport and Main Roads in 2019. The study is reviewing interim, short-term and long-term options for improving safety in the Lindum Station precinct.

The ATSB notes on 23 July Brisbane City Council confirmed it had already commenced work on immediate upgrades to the level cross intersection on Kianawah Road, including signalisation and reconfiguring the intersection.

Mr McNamara said the ATSB’s preliminary report does not include any safety findings or analysis, which will be detailed in the investigation’s final report.

“The ATSB’s investigation will further assess the recorded data and sequence of events leading up to the collision, along with the level crossing’s design of the and its similarity to other crossings,” he stated.

“The investigation will also further examine maintenance activity associated with the level crossing and approach roads, the history of inspections by the rail and road managers, and the history of incidents and accidents at the level crossing and connecting intersections.”

A final report will be published at the conclusion of the investigation.

Read the preliminary report: Level crossing collision between passenger train and road vehicle, Wynnum West, Queensland, on 26 February 2021

Operators and owners of piston-engine aircraft are again urged to use active warning CO detectors

An exemplar active CO detector. Passive spot detectors have known limitations

Key points: 

• Pilot began feeling unwell shortly after take-off, was likely exposed to elevated levels of CO; 
• CO is an odourless, colourless gas, and may not be detected until physical symptoms and cognitive effects develop; 
• Operators and owners of piston-engine aircraft are encouraged to use an active CO detector with active audio and visual alerts. 

The Australian Transport Safety Bureau (ATSB) is again urging operators and owners of piston-engine aircraft to use an active warning carbon monoxide detector, following the partial incapacitation of the pilot of a Piper PA-28 light aircraft near Moree last year. 

Shortly after take-off from Moree on 23 September 2020, the pilot began feeling unwell, experiencing a warm feeling in their chest, dizziness, breathlessness, some confusion and disorientation. 

The pilot then noticed a discolouration of the cabin’s disposable carbon monoxide (CO) spot detector, which rapidly darkened. They immediately returned to the airport, reduced engine power and opened all the fresh air vents and the side window. 

After a safe landing, the pilot was taken to hospital where their carboxyhaemoglobin level was recorded as being mildly elevated. The pilot was given supplemental oxygen, and began feeling better after about 2 hours. 

After the incident, engineers conducted ground runs on the aircraft, which confirmed CO was leaking into the cabin, with a new disposable CO spot detector also showing discolouration. Further inspection revealed 4-5 pinholes in the exhaust stack that were not covered properly, and unserviceable scat (air duct) hoses. Upon repairing the pinholes and replacing the scat hoses, ground runs found no indication of CO in the cabin. 

“The positive indications on two separate disposable CO spot detectors, both during the flight and during ground runs afterwards, indicated that the pilot was likely exposed to elevated levels of CO in the aircraft cabin,” said ATSB acting Director Transport Safety Kerri Hughes. 

“CO is a colourless and odourless gas, and its presence may not be detected until the physical symptoms and cognitive effects present themselves.” 

Ms Hughes noted that, while in this incident the disposable spot detector was effective in warning the pilot of the presence of CO, they do have known limitations. 

“Although commonly used in general aviation, a spot detector is a passive device that relies on the pilot regularly monitoring it for discolouration. 

“In addition, identifying a positive indication is also dependent on the detector being easily visible and accessible.” 

In 2020, the ATSB highlighted its concerns regarding exposure to CO when it issued two Safety Advisory Notices arising from its investigation into the collision with water of a DHC-2 Beaver aircraft in Jerusalem Bay, north of Sydney on 31 December 2017, in which the pilot and five passengers were fatally injured. Toxicological testing of blood samples found the pilot and two passengers had elevated levels of CO. The aircraft was fitted with a disposable CO spot detector. 

The first Safety Advisory Notice, to maintainers of piston-engine aircraft, highlighted the importance of the thorough inspection of exhaust systems and the timely repair or replacement of deteriorated components. 

The second Safety Advisory Notice, to piston-engine aircraft owners and pilots, reiterated the importance of the use of an active CO detector in the cabin.  

“The ATSB strongly encourages owners and operators of piston-engine aircraft to use a CO detector with an active warning,” said Ms Hughes. 

“These devices are inexpensive and widely available, and they provide pilots with the best opportunity to detect CO exposure before it adversely affects their ability to control the aircraft, or they become incapacitated.” 

Read the report: Partial pilot incapacitation involving Piper PA-28, VH-TBB, 19 km south-east of Moree, New South Wales, on 23 September 2020

The Australian Transport Safety Bureau today welcomes the Australian Government’s appointment of Angus Mitchell as the agency’s next Chief Commissioner and Chief Executive Officer.

Mr Mitchell will commence his five-year term on 2 September 2021, succeeding Greg Hood, who retired on 30 June. In the interim, ATSB Chief Operating Officer Colin McNamara will continue as the Acting Chief Commissioner.

“As the incoming Chief Commissioner I am excited to bring my 30 years’ of professional experience to help the ATSB continue to evolve as a global leader in transport safety investigation, research and analysis, and influence the implementation of positive safety action,” Mr Mitchell said.

“I have long admired and respected the quality and professionalism of the Bureau’s independent ‘no-blame’ investigation reports, and I am looking forward to helping ensure the ATSB continues as a world-leading best practice safety investigation agency which influences the national and international safety agenda.”

Mr Mitchell joins the ATSB from Maritime Safety Queensland, where as General Manager he oversaw the safe and efficient movement of vessels into and out of Queensland’s 21 ports, and was responsible for compliance activities and safety investigations for Australia’s largest recreational maritime fleet.

Maritime Safety Queensland recently was recognised with an Australian Industry and Shipping Award for its role in managing international shipping throughout the COVID pandemic and supporting the welfare and safety of international seafarers.

Prior to leading Maritime Safety Queensland, Mr Mitchell was the Executive Director of NSW Maritime, where he oversaw Australia’s largest state’s primary maritime regulatory, investigative and compliance agency. He has also served as Deputy Harbour Master – Operations for Sydney Ports, where he was responsible for managing day-to-day port operations for both Sydney Harbour and Port Botany.

Mr Mitchell also proudly served as an officer in the Royal Australian Navy for 14 years, undertaking a number of operational and policy roles.

“Angus Mitchell becomes the fourth Chief Commissioner of the ATSB, and the first with a maritime industry background,” said Acting Chief Commissioner Colin McNamara.

“We look forward to the extensive experience and expertise Angus will bring to the ATSB, and to our transport safety investigations.”

The unplanned activation of take-off/go-around mode during the landing of a Fokker F100 highlights that flight crews can be faced with non-normal situations that require good judgement and expertise to safely manage, according to an Australian Transport Safety Bureau investigation into the incident.

On 1 September 2020, Virgin Australia Regional Airlines Fokker F100 VH-FNR was landing at West Angelas aerodrome in Western Australia’s Pilbara region, on a scheduled passenger service from Perth.

Just prior to touching down, the aircraft’s take-off/go-around (TOGA) mode activated, preventing automatic deployment of the lift dumpers to slow the landing roll.

The flight crew reported that, after touching down right wheel first, they selected the engine thrust reverser levers to the idle position, however they did not deploy. The thrust reversers were selected a second time, but again they did not deploy.

The first officer then moved the levers beyond reverse idle and applied manual braking, at which point both thrust reversers and lift dumpers deployed. The landing then proceeded as normal.

After the landing, the captain observed on the primary flight display that the go-around (GA) flight mode was active. The multi-function display unit also indicated the TOGA thrust mode.

The ATSB’s investigation into the event concluded that the TOGA mode activated for an unexplained reason, preventing automatic activation of the lift dumpers.

In addition, the weight on wheels sensors gave an intermittent signal during landing. This was most likely due to a softer than typical landing, combined with the lift-dumpers not automatically deploying due to the TOGA mode being activated.

The intermittent weight on wheels signal delayed the manual activation of the lift dumpers and deployment of reverse thrust.

“Despite the high reliability of modern flight control systems, this event highlights that flight crews can still be faced with non-normal situations that require their combined judgement and expertise to safely manage,” said ATSB Director Transport Safety Dr Stuart Godley.

“Delayed deployment of reverse thrust, lift dumpers, or a combination of the two, has contributed to runway overruns in the past.”

Under normal operation, the F100’s TOGA mode is selected by pulling two triggers located on the thrust levers. The flight crew reported the motion to actuate the triggers would be an intentional one, and they did not believe it could happen accidentally.

After the incident, maintenance engineers tested the TOGA switches, weight on wheels sensors, lift dumpers, thrust reversers, flight computers and autothrottle systems. No anomaly or unserviceability was found.

The aircraft was then returned to service, and at the time of publication there had been no reoccurrences of inadvertent TOGA mode activations.

Read the final report: Avionics system event involving Fokker F100, VH-FNR, West Angelas Aerodrome, Western Australia, on 1 September 2020

Key points:

• Blockage in the left pitot tube prevented water escaping, obstructing air flow;
• Incorrect airspeed indications were displayed on the left PFD, triggering miscompare alerts;
• Spurious instrument readings can create a more complex scenario for pilots than a complete instrument failure

Differing airspeed indications on a PC-12 aircraft’s two primary flight displays due to a blocked pitot tube underscores the complexity of managing spurious instrument readings, an Australian Transport Safety Bureau (ATSB) investigation notes.

On the evening of 22 June 2020, a Royal Flying Doctor Service Pilatus PC-12/47E was conducting a positioning flight from Perth’s Jandakot Airport to Albany, on Western Australia’s southern coast, with a pilot, a doctor and a flight nurse on-board.

On descent to Albany while passing through flight level 180 and in icing conditions, the pilot observed an airspeed miscompare indication on the aircraft’s left primary flight display (PFD).

The pilot then compared the airspeeds displayed on the left and right PFDs with the airspeed indication on the aircraft’s standby instruments (the electronic secondary instrument system/ESIS), and determined that the left PFD was likely displaying incorrect information.

Assessing that a blocked pitot tube was likely causing erroneous data, the pilot requested clearance from air traffic control to climb to FL230 to get clear of cloud and avoid the worst of the icing conditions.

During the climb, the airspeed displayed on the left PFD exceeded the aircraft’s maximum operating speed, resulting in audible overspeed alerts, and the pilot elected to return to Jandakot rather than continue to Albany.

During the return to Jandakot, while descending the aircraft to exit icing conditions and cloud, the left PFD’s indicated airspeed reduced to zero, however, no stall warning activated. In addition, heading data on the left and right PFDs diverged, resulting in a heading miscompare indication on the left PFD, while the left PFD would also display an incorrect attitude.

Approaching Jandakot the pilot reported that all indications returned to normal until the aircraft was on short final to land when an altitude mismatch and low airspeed warning was identified on the PFDs

The aircraft landed without further incident.

Post flight, an initial aircraft examination revealed a small amount of foreign material was blocking the left pitot tube drain.

“During the flight, water entered the left pitot tube either as rain or an accumulation of moisture from flying through cloud,” said ATSB Director Transport Safety Stuart Macleod.

“The blockage meant the water was unable to escape, and this in turn obstructed the flow of air to the aircraft’s air data attitude heading reference system, resulting in an incorrect airspeed being displayed on the left PFD.”

In addition, the heading miscompare was likely caused by the aircraft’s movement through moderate to severe turbulence during the return to Jandakot, Mr Macleod noted.

About a month prior to the incident the pilot had undertaken an operational proficiency check flight under the guidance of a check and training captain, which included observing the aircraft’s performance at various engine power settings and attitude combinations.

“The pilot advised the ATSB that this check flight had given them more confidence in the assessment that it was likely a pitot tube blockage and that the right PFD and ESIS were showing the correct information,” Mr Macleod said.

“Spurious instrument readings can create a more complex scenario for pilots than a complete instrument failure.

“Unlike in this incident, erroneous overspeed readings have had serious consequences when not properly diagnosed.”

Read the final report: Unreliable Airspeed Indication involving Pilatus PC-12/47E, VH-OWI, near Albany, Western Australia, on 22 June 2020

The collision of a passenger train with the open hatch of an adjacent locomotive emphasises the need for appropriate risk controls to prevent hatches from opening during service, a safety investigation has concluded.

On the evening of 21 July 2020, a passenger train bound for Kiama collided with the air filter hatch of a stationary Pacific National NR locomotive near Loftus station, on Sydney Trains’ Illawarra line.

There were no injuries reported, but the guard’s windscreen and passenger doors on the lead carriage of the passenger train were damaged in the collision.

An investigation into the incident was undertaken by the Office of Transport Safety Investigations (OTSI), which conducts rail safety investigations in NSW on behalf of the ATSB.

It concluded the air filter hatch was likely not properly secured during recent maintenance. This was then missed during roll-by inspections, as the design of the hatch and locks meant that the hatch could appear visibly closed and locked without it being secured correctly.

Open, and able to swing perpendicular to the train, the hatch exceeded the rolling stock outline*, thus becoming out of gauge. This allowed the hatch to infringe on the outline of the oncoming passenger train on the adjacent track.

The Australian Standard for Rolling Stock Outlines (AS 7507:2017) specifies external hatches should be designed such that when open they do not protrude from the kinematic envelope (i.e. outline) of the rolling stock.

“If this cannot be achieved, the Australian Standard suggests a range of secondary measures that can prevent an incident like this one occurring,” said OTSI Chief Investigator and CEO Dr Natalie Pelham.

“While not mandatory, the Standard provides industry with guidance on recommended practices that can reduce the risk of an incident occurring and improve safety for everyone using the network.

“Rail transport operators should review their rolling stock to ensure that appropriate risk controls are in place to prevent hatches from opening while in service and becoming out of gauge.”

Following the incident, Pacific National and its maintenance provider United Group Limited (UGL) conducted an assessment of the NR locomotive fleet, which identified the locomotives’ CA10 communications cabinets featured a hatch which could also exceed the rolling stock outline if not properly secured.

As a result, Pacific National and UGL have released a modification to fit a secondary latch to the air filter and CA10 hatches on all NR locomotives.

The intent of the modification is to prevent a hatch from exceeding the rolling stock outline if it was not properly secured or the lock was to fail.

Pacific National and UGL also issued a bulletin to maintenance staff in November 2020, detailing the correct procedure for securing hatches, and conducted an inspection to check the integrity of locks and hinges on air filter hatches across the NR locomotive fleet.

* The maximum permissible dimension a train must remain within to maintain acceptable clearances between rolling stock, structures and passing trains.

Read the final report: Collision between out of gauge freight train 3WB3 and passenger train C181, Loftus, New South Wales, on 21 July 2020

Key points:

• Student pilot and Instructor did not detect forecast deteriorating weather during their pre-flight briefing;
• Pilots should maintain knowledge and skills required to avoid unintentional operations in IMC;
• If a VFR-rated pilot does find themselves in marginal weather, they should seek whatever assistance is available, including contacting air traffic services.

An incident that saw a student pilot and instructor in a Piper PA-28 encounter deteriorating weather and enter instrument meteorological conditions (IMC) while operating under visual flight rules (VFR) highlights the importance of thorough pre-flight planning, an Australian Transport Safety Bureau investigation notes.

The student pilot (in the left seat) and instructor (in the right hand seat), with a second student pilot (seated in the rear) observing, were conducting a navigation training flight in the PA-28 from Melbourne’s Moorabbin Airport to Warrnambool in western Victoria and return on 25 February 2021, as part of the student’s integrated commercial pilot licence training.

After refuelling at Warrnambool the aircraft departed to return to Moorabbin in visual flight conditions, with the plan that they would return to Warrnambool if the weather deteriorated.

As the flight progressed, and as had been forecast, the weather deteriorated, and the instructor decided to divert to Cobden Airport to land and wait until the weather cleared.

However, visibility significantly reduced in rain, and the instructor, who held an instrument rating but had not conducted any instrument flying since a March 2020 proficiency check (and therefore did not meet the currency requirements for single-pilot instrument flight rules flights), took control of the aircraft and the decision was taken to return to Warrnambool.

As the aircraft approached Warrnambool, visibility continued to reduce and the cloud base began to lower. The instructor then initiated a climb into cloud and contacted air traffic control, which provided navigation assistance to an area free from cloud, issuing a heading to Avalon Airport.

The aircraft, which was certified for day and night VFR operations only, subsequently exited cloud about 10 nm south-west of Avalon Airport, with the flight then continuing to Moorabbin for an uneventful landing.

“The ATSB found that although the pilots had conducted a pre-flight briefing, they did not detect the forecast deteriorating weather in the Warrnambool area,” said ATSB Director Transport Safety Stuart Macleod.

“In addition, prior to departure from Warrnambool they did not assess the aerodrome forecasts for both Moorabbin and Warrnambool to ensure they were suitable destination airports.

“This probably resulted in them selecting Warrnambool as an alternate airport, despite the forecast temporary deterioration, and the aircraft encountering poor weather during the return to Warrnambool.”

Mr Macleod said weather related incidents continue to be a significant concern in aviation safety.

“The ATSB encourages pilots of all experience levels to develop and maintain the knowledge and skills required to avoid unintentional operations in IMC,” he said.

“And if a VFR-rated pilot does find themselves in marginal weather, they should seek whatever assistance is available, including contacting air traffic services.”

Mr Macleod said the ATSB’s 'Don't push it, Don't go' safety education campaign provides further information on the risks of VFR into IMC flight.

“Don’t push it, Don’t go’ highlighted three key messages: the importance of thorough pre-flight planning and having alternate plans, that pressing on where there is the possibility of entering IMC carries a significant risk of spatial disorientation, and the value of using a ‘personal minimums’ checklist to help manage flight risks,” he said. 

“Pilots without a current instrument rating should always be prepared to amend and delay plans to fly due to poor or deteriorating weather conditions, and not to push on.

“Thorough pre-flight preparation is the best defence against flying into deteriorating weather."

Read the report: VFR into IMC involving a Piper PA-28, VH-FPS, near Warrnambool, Victoria, on 25 February 2021

A Robinson R22 helicopter which collided with terrain while mustering showed evidence of a wirestrike, the ATSB’s preliminary report from its on-going investigation into the 26 May 2021 accident details.

The pilot, the sole occupant on board, was mustering cattle along a fence line on a property 75 km west of Hay, NSW, and had landed to open a gate at the entrance to a yard. Shortly after, a witness heard the helicopter take-off and, very soon after, a loud bang.

Suspecting an accident, the witness drove to the site and found the helicopter on its side, substantially damaged. First aid was rendered to the pilot, however they had sustained fatal injuries.

Subsequent analysis of recorded flight data by ATSB transport safety investigators indicated that after taking off after the pilot had opened the gate, the helicopter flew south towards another gate, at between 20 and 30 feet (6 to 9 metres) above ground level, and at a speed of up to 27 knots. The track then turned slightly towards the second gate which was required to be opened to allow the cattle through.

This gate was adjacent to the accident site, which was about 27 metres from a single wire earth return (SWER) powerline which ran across the yards with a minimum height between spans of 24 feet (7 metres).

Examination of the helicopter’s flight controls, engine and structure did not identify any pre-existing defects. However, there was evidence of wirestrike marks on the front of the helicopter’s left skid.

Director Transport Safety Stuart Macleod noted that the ATSB’s preliminary report does not include any safety findings or analysis, which will be detailed in the investigation’s final report.

“As the investigation progresses, the ATSB will continue to analyse recorded data, the aircraft’s maintenance documentation and operational records, weather information, and assess visibility of the powerline, accident survivability and the pilot’s qualifications and experience,” he said.

A final report will be released at the conclusion of the investigation.

“However, should a critical safety issue be identified at any time during the investigation, the ATSB will immediately notify relevant parties so appropriate and timely safety action can be taken.”

Read the preliminary report: Wirestrike and collision with terrain involving Robinson R22, VH-KLY, 75 km west-north-west of Hay, New South Wales, on 26 May 2021