An aerial application-specific flight risk assessment would likely have identified the elevated risks that a high workload, fatigue, task complexity and weather presented to the pilot of an Air Tractor AT-400 aircraft that aerodynamically stalled and collided with the ground, an ATSB investigation report details.

The accident occurred at the end of the pilot’s fifth spray run, during their eleventh spray load of the day, while spraying at a property about 75 km from Moree, NSW on 4 December 2021.

“The ATSB found that the aircraft was too close to the start of the spray run during the turn, which probably resulted in the pilot tightening the turn,” said ATSB Director Transport Safety Dr Stuart Godley.

“This almost certainly resulted in an aerodynamic stall at a height too low to recover before colliding with the ground.”

After being reloaded with chemical and refuelled, the AT-400 had returned to the western side of the target block, where the pilot had been spraying in a racetrack pattern on the previous load, the report details.

After descending to recommence spraying towards the south, the aircraft climbed and turned away to track north and overfly a flood-affected area. The pilot radioed the company operations manager expressing concern about the weather conditions and the potential for chemical to drift onto a neighbouring property. About 5 minutes later, the aircraft returned to the target block, this time on the eastern boundary. 

The pilot then conducted 2 ‘smoker’ runs to assess the drift, followed by 5 back-to-back (parallel) spray runs. At the end of the fifth spray run, the aircraft was observed to climb then enter a right procedure turn.

During the turn, the aircraft descended rapidly, collided with terrain, and was subsequently destroyed by fire. The pilot sustained fatal injuries.

“Mishandling the turn was probably a result of the combined effects of the pilot experiencing high workload and fatigue due to long flight and duty times, inexperience, the complexity of the task and the weather conditions,” said Dr Godley.

“The combination of these factors would likely have identified an elevated flight risk, had an aerial application-specific flight risk assessment been conducted. However, there was no requirement for the operator or pilot to conduct a flight risk assessment or to have a flight risk assessment tool.”

As a result of this accident, the operator has implemented additional fatigue management measures, which include an assessment of other factors that may contribute to fatigue and flight risk, within the regulatory fatigue requirements.

The investigation also considered aspects of pilot survivability of the accident, and notes that the pilot was almost certainly wearing a helmet and 4-point restraint, which increased their chances of survival in an accident. However, the aircraft’s fuel tanks ruptured during the accident sequence resulting in a fire and fatal thermal injuries to the pilot.

“The aircraft was not fitted with a crash-resistant fuel system, nor was it required to be,” noted Dr Godley.

The ATSB found that on average, post-impact fire in VH-registered certified aeroplanes has resulted in one fatality every 2 years in Australia.

“As such, post-impact fire presents a significant risk of fire-related injuries and fatalities to occupants of general aviation aeroplanes.”

Crash-resistant fuel systems have been proven effective in helicopters and in automotive applications, Dr Godley noted.

“As such, the ATSB has issued a formal Safety Recommendation to the US Federal Aviation Administration to take action to address certification requirements for crash-resistant fuel systems for fixed wing aircraft to reduce the risk of post-impact fire.”

Read the final report: Collision with terrain involving Air Tractor AT-400, VH-ACQ 75 km west-south-west of Moree, New South Wales, on 4 December 2021

A Dynaero aircraft’s partial power loss soon after take-off from Serpentine Airfield, WA created a demanding, time-critical situation prior to a fatal collision with terrain, an ATSB investigation report outlines.

On the afternoon of 28 December 2020, the single-engine Dynaero MCR-01 light aircraft took off from Serpentine Airfield, south of Perth, to conduct a post-maintenance check flight.

About 300 ft above ground level, the aircraft’s engine began to run rough, but continued to operate. The pilot commenced a turn to the left, and the aircraft appeared to decelerate in a nose-high attitude without gaining height.

Shortly after, the aircraft was observed to aerodynamically stall, pitch nose-down, and impact terrain. The pilot, who was the sole occupant, was fatally injured, and the aircraft was destroyed.

The ATSB investigation’s final report notes this accident is another reminder of the challenges pilots face in the event of a partial power loss after take-off, as detailed in the ATSB’s Avoidable Accidents handbook.

“Partial engine power loss is a more frequent, and a more complex occurrence than complete engine power loss,” ATSB Director Transport Safety Dr Stuart Godley said.

“The ATSB encourages pilots to review the recommended partial power loss procedure in their aircraft’s pilot operating handbook, and cautions against attempting to turn back towards the runway under reduced power unless in controlled situations where sufficient altitude exists."

The ATSB found multiple maintenance tasks in the aircraft’s return to service after a significant period of inactivity were not adequately carried out, and that the left carburettor of the aircraft’s engine was missing a component, and contained a significant amount of contamination.

“This likely resulted in over-fuelling of the carburettor at a low power setting, and likely produced subsequent engine rough running at higher power settings,” Dr Godley explained.

Additionally, the ATSB found the pilot was unfamiliar with the aircraft and engine type, which increased the risk of not being able to adequately manage an inflight emergency.

The ATSB also found the pilot had probably consumed a significant amount of alcohol the night before the accident, which increased the risk of post-alcohol impairment.

“Blood-alcohol can persist the day after significant alcohol consumption, and the residual effects of alcohol may impair performance, especially in demanding and time critical situations,” Dr Godley concluded.

Read the final report: Partial power loss and collision with terrain involving Dynaero MCR-01 VLA, VH-SIP, near Serpentine Airfield, Western Australia, on 28 December 2020

The Australian Transport Safety Bureau has released a preliminary report detailing factual information as part of its on-going investigation into the 2 January 2023 mid-air collision of two sightseeing helicopters at the Gold Coast.

The two Eurocopter EC130 helicopters were being operated by Sea World Helicopters (a separate corporate entity to the theme park) on 5-minute scenic flights. One helicopter with a pilot and 5 passengers on board was on approach to land at a helipad adjacent to the Sea World theme park and the second, with a pilot and 6 passengers, had just departed a separate but nearby helipad within the theme park when they collided above the Broadwater.

“The ATSB has released this preliminary report to detail the circumstances of this tragic accident as we currently understand them, but it is important to stress that we are yet to make findings,” said ATSB Chief Commissioner Angus Mitchell.

“Our findings as to the contributing factors to this accident, and the analysis to support those findings, will be detailed in a final report to be released at the conclusion of our investigation.”

Mr Mitchell said the preliminary report details factual information, including the accident’s sequence of events.

“The factual information detailed in this report is derived from interviews with survivors of the accident, including the surviving pilot and passengers, and witnesses; analysis of video footage and images taken by passengers on board both helicopters, onlookers on the ground, and CCTV from nearby buildings; examination of the wreckage of both helicopters; and a review of recorded radio calls and aircraft tracking and radar data.”

The preliminary report details that the helicopters were operating from two separate helipad facilities about 220 metres apart, a pad within the theme park, and a pad to the south at the operator’s own heliport, adjacent to the park. The 5-minute scenic flights were to follow the same counter-clockwise orbit, with the inbound helicopter, registration VH-XH9 (XH9) on approach to land at the heliport to the south and the outbound helicopter, registration VH-XKQ (XKQ) having departed the pad to the north from within the theme park.

The two helicopters collided at an altitude of about 130 feet, 23 seconds into the departing XKQ’s flight.

The main rotor blades of helicopter XKQ entered the forward cabin of XH9. XKQ broke apart in mid-air and impacted shallow water next to a sandbar. The pilot and 3 passengers were fatally injured, and 3 passengers were seriously injured. The helicopter was destroyed.

Helicopter XH9 sustained significant damage to the forward cabin, instrument console, and main rotor blades. The impact turned XH9 to the left, and the pilot continued with the momentum of that movement, completing a 270° descending turn to land on the sandbar below them near to XKQ. The pilot and 2 passengers were seriously injured, and 3 other passengers had minor injuries.

The helicopters were operating in non-controlled airspace where pilots use a common traffic advisory frequency (CTAF) to make radio calls to announce their position and intentions, and, as required, to arrange separation with other aircraft.

The report details the radio calls made by the pilot of the returning helicopter XH9, and that as they tracked south over the Broadwater, that the pilot saw passengers boarding XKQ as it was preparing to depart.

The pilot of XH9 recalled that their assessment was that XKQ would pass behind them, and that they did not recall the pilot of XKQ making a standard “taxiing” call announcing their intention to depart.

“This does not necessarily mean that a taxi call was not made, and the ATSB investigation will undertake a detailed analysis of the nature of the radio calls made,” Mr Mitchell noted.

The report also details that the pilot of XH9 did not see XKQ depart from the park helipad.

While video footage taken by passengers in both helicopters on mobile phones contained images of the other helicopter, this does not mean that the other helicopter was visible to either pilot.

“The investigation will look closely at the issues both pilots faced in seeing the other helicopter,” Mr Mitchell said.

“We have already generated a 3D model of the view from the pilot’s seat from an exemplar EC130 helicopter which we will use as part of a detailed visibility study to help the investigation determine the impediments both pilots faced in sighting the other helicopter.”

Mr Mitchell said the investigation will also look more broadly beyond the issues of radio calls and visibility.

“The ATSB will also consider the operator’s procedures and practices for operating scenic flights in the Sea World area and the process for implementing the recently-acquired EC130 helicopters into operation, and will review the regulatory surveillance of the operator and similar operators.”

The investigation would also look at the use of traffic collision avoidance systems (TCAS). There was no requirement for the helicopters to be equipped with a collision avoidance system, and while both accident helicopters were fitted with TCAS, those systems had not been fully integrated in the accident helicopters (as they had with the operator’s other helicopters), and according to the operator’s pilots were of limited benefit when operating near and on the helipads.

“This will be a complex and comprehensive investigation.

“However, if at any time during the course of the investigation the ATSB identifies a critical safety issue, we will immediately share that information with relevant parties so they can take appropriate safety action.”

Read the preliminary report: AO-2023-001: Mid-air collision involving Eurocopter EC130B4, VH-XH9, and Eurocopter EC130B4, VH XKQ Main Beach, Gold Coast, Queensland on 2 January 2023

The ATSB will monitor the planned introduction of a revised Sydney Airport standard instrument departure (SID), after a loss of separation occurrence involving two widebody airliners shortly after take-off last year.

On the afternoon of 28 September 2022, a Boeing 787-9, operated by British Airways, took off from Sydney’s runway 16R for a scheduled passenger service to Singapore.

Approximately three minutes later, an Airbus A330-200, operated by Qantas, departed the same runway for a scheduled passenger service to Cairns.

Both aircraft were directed to follow the same standard instrument departure (SID) routing, the DEENA 7 SID, for their respective climbs to 28,000 ft.

This SID required the aircraft to meet two separate conditions after take-off before turning to the north-west: they had to pass the DEENA waypoint, and they had to climb to at least 6,000 ft.

“Because aircraft have to satisfy two separate conditions prior to turning, there is no way to ensure aircraft will turn at the same location when conducting the DEENA 7 SID,” ATSB Director Transport Safety Stuart Macleod explained.

In the September incident, the trailing A330 was being used on a domestic flight, with a correspondingly lower fuel load and higher climb performance than it would have had for an international flight.

“The departure controller did not expect this, and instead expected the A330 to have a similar climb performance to the 787 it was following, thus remain behind it and turn at about the same location,” Mr Macleod said.

Instead, the A330 reached 6,000 ft as it passed DEENA, and began its turn about 20 km from the airport. Meanwhile, the heavier 787 reached 6,000 ft some time after passing DEENA, and began its own turn about 25 km from the airport.

This meant the trailing A330 was turning inside the path of the 787, as they both climbed to the same flight level.

During the event, separation between the aircraft reduced to 2.4 NM laterally, and 600 ft vertically – below the required separation standards of either 4 NM laterally (for ‘heavy’ aircraft) or 1,000 ft vertically – before the controller advised the aircraft and separation was re-established.

The British Airways flight crew later advised they had received a traffic collision avoidance system (TCAS) traffic advisory during the event, and the first officer had subsequently visually identified the A330.

“Maintaining separation in high traffic terminal areas, such as Sydney, requires that both controllers and flight crews remain vigilant, maintain open communications, and use the available systems and tools to minimise the risk of errors,” Mr Macleod said.

“When sequencing departures, controllers should consider a number of factors, including how the flight duration (and the associated fuel load) will likely affect aircraft climb performance.”

The ATSB final report notes that, in the last decade in Australia, there have been eight loss of separation occurrences involving aircraft cleared on a SID, where a following aircraft has climbed faster than the preceding aircraft.

Of these, six were at Sydney, and five involved the DEENA 7 SID.

“Airservices Australia has advised the DEENA 7 SID has been redesigned to remove the two conditional requirements of the procedure,” Mr Macleod said.

“The changes are planned to be part of the first implementation package for Western Sydney International Airport, but as the timeframe for this implementation is unknown, the ATSB will continue to actively monitor this open safety issue,” Mr Macleod concluded.

Read the final report: Loss of separation involving Airbus A330, VH-EBK and Boeing 787, G-ZBKF, near Sydney Airport, New South Wales, on 28 September 2022

An Australian Transport Safety Bureau interim report details a pair of occurrences involving Boeing 737-800 passenger aircraft which descended below minimum altitude constraints on approach into Cairns Airport, in North Queensland, in October 2022.

The interim report aims to provide timely information, gathered in the early evidence collection phase of the investigation, which is on-going. It contains no analysis or findings, which will be detailed in the final report.

In each occurrence, flight crews (one Virgin Australia, the other Qantas) entered the same standard arrival (HENDO 8Y) and approach (RNP Y runway 33) into their flight management computers, ahead of a planned landing on runway 33 at Cairns. However, neither flight crew selected the required approach transition.

In both cases, when presented with the discrepancy by the flight management computer, flight crews resolved it by manually connecting the arrival waypoint HENDO to the intermediate approach fix waypoint noted on the approach chart.

“As an unintended consequence, this removed the 6,800 ft descent altitude constraint associated with the initial approach fix waypoint in each aircraft’s programmed flight path,” ATSB Director Transport Safety Stuart Macleod explained.

“In both occurrences, the aircraft therefore descended below that constraint, as well as the 6,500 ft minimum sector altitude in that segment of airspace.”

In both cases, air traffic control alerted flight crews of their low altitude. No terrain warnings were triggered in either occurrence.

“The first flight, on October 24, took place on a dark night, so the Virgin Australia flight crew conducted a go-around, and then landed without further incident,” Mr Macleod said.

“The second flight, on October 26, occurred in daylight under visual conditions, so the Qantas flight crew was approved for a visual approach by air traffic control, and landed without further incident.”

To date, the ATSB has interviewed the flight crews, examined recorded flight data, reviewed air traffic control audio and surveillance data, and reviewed operator and air traffic control procedures.

The interim report notes both operators have already taken steps to provide flight crews with further guidance, relating in particular to approaches where the selection of an approach transition is required.

“Going forward, the ATSB’s investigation will include further review and examination of the evidence gathered, as well as instrument procedure and waypoint naming processes and standards, and arrival and approach chart information and presentation,” Mr Macleod said.

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

“However, should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify relevant parties so that appropriate and timely safety action can be taken,” Mr Macleod concluded.

Read the interim report AO-2022-051: Flight below minimum altitude occurrences, 40 km south of Cairns Airport, Queensland on 24 and 26 October 2022

A preliminary report has detailed factual information established in the early evidence collection phase of the ongoing investigation into the derailment of a freight train near Geelong, Victoria on the morning of 14 November 2022.

The transport safety investigation is being conducted by the Chief Investigator, Transport Safety, who conducts rail investigations in Victoria on behalf of the Australian Transport Safety Bureau.

The report notes that the freight train was travelling at about 80 km/h over a culvert near Inverleigh, west of Geelong, when 16 of its 55 wagons derailed.

Significant rainfall was recorded at Inverleigh in the 12-hour period prior to the derailment, and the embankment supporting the track at the location of the culvert collapsed.

The incident resulted in substantial track damage, and 16 destroyed wagons. There were no injuries.

“Since attending the derailment site and completing a site and train inspection, investigators have examined drainage in the waterway catchment area and commenced hydrology studies,” Chief Investigator, Transport Safety Mark Smallwood said.

“Investigators have also examined operational information, conducted interviews, and commenced collecting other relevant information.”

Mr Smallwood said investigation will further review the waterway catchment, weather warnings in the area, the effect of prior rainfall on soil moisture and catchment flow and culvert design, including capacity.

Investigators will also review maintenance of track infrastructure and train operation.

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

“However, should a critical safety issue be identified during the course of the investigation, relevant parties will be notified immediately, so appropriate and timely safety action can be taken,” Mr Smallwood said.

Read the preliminary report: Derailment of freight train 4PM9 Inverleigh, Victoria, on 14 November 2022