The derailment of a freight train wagon following a ruptured wheel in the wagon’s ‘B’ end wheelset highlights potential limitations of field inspections for the detection and monitoring of fatigue cracks, a new ATSB investigation says.

SCT Logistics freight train 6MP9 was travelling from Melbourne to Perth early on the morning of 4 January 2019. While on the Fisher-Thomair section of track near Cook, South Australia, a single wagon derailed due to a ruptured wheel. While no other wagons derailed, damage to sleepers and clips was found in the area of the derailment

Prior to the derailment, the train had passed over two wayside detectors designed to alert the operator of abnormalities that might indicate wheel or bearing damage. However, there was no record of any alerts received from these detectors.

While vigilant field inspections are a useful tool for the detection and monitoring of fatigue cracks, they are not infallible and should be used with an understanding of their limitations.

ATSB Director Transport Safety, Stuart MacLeod said the derailment was due to fatigue cracking in the ruptured wheel.

“Metallurgical examination found a fatigue crack had initiated in the wheel flange and then propagated into and around the wheel plate and rim, causing the wheel to fail and break into multiple pieces,” Mr Macleod said.

“The fatigue crack was found to have initiated in an area of the wheel that showed signs of sliding contact with the rails. Sliding contact can cause thermal damage to the wheel leaving a white etching layer that is brittle and more susceptible to cracking.” 

Mr Macleod noted that at the last inspection, the flange fatigue crack was likely observable but was either not detected, or was deemed acceptable under the work instruction provided. This work instruction provided guidance that was less conservative than the Australian Standard, but it was not possible to establish whether compliance with the standard would have prevented the occurrence.

 “This incident demonstrates that while vigilant field inspections are a useful tool for the detection and monitoring of fatigue cracks, they are not infallible and should be used with an understanding of their limitations,” Mr Macleod said.

“Further, selection of the appropriate materials for wheels can also assist in reducing the occurrence of fatigue cracks and subsequent failures.”

Since the incident the operator has worked with its maintenance provider to develop an improved inspection process for wheels exhibiting brakes issues, particularly sticking brakes, an issue known to lead to the development of thermal cracking.

The operator is also phasing out the ruptured wheel class type from its fleet.

Read the final report: Derailment of SCT Logistics freight train 6MP9, near Cook, South Australia, on 6 January 2019

The Australian Transport Safety Bureau has issued a Safety Advisory Notice to commercial hot air balloon operators recommending they review their operational practices to reduce the risk of passenger injury when using vehicles to assist with balloon deflations. 

The Safety Advisory Notice arises from an ATSB investigation into a 16 March 2019 incident near Coldstream, Victoria where two passengers sustained injuries when the basket of a Kavanagh B-400 balloon operated by Picture this Ballooning tipped over when a vehicle was being used to assist the deflation of the balloon envelope.

Due to the lack of wind and the large size of the envelope, after the completion of a scenic flight the crew elected to use the recovery vehicle to assist in pulling the envelope over during deflation by attaching the crown line—a rope attached to the top or crown of the balloon—to the vehicle then slowly driving forward.

During this process, with 16 passengers and the pilot on board, the vehicle inadvertently pulled the basket over, resulting in one passenger sustaining broken ribs and another being knocked unconscious.

The ATSB’s investigation into the accident found that the operator had not conducted a risk assessment concerning the use of vehicle-assisted deflations.  

The ATSB advises all commercial balloon operators utilising vehicle‑assisted deflation to review their current operational practices with the aim of mitigating the safety risks associated with the procedure. 

ATSB Director Transport Safety Dr Stuart Godley said while not required by regulation, the lack of a risk assessment for vehicle-assisted deflation likely left the operator and crew unaware of the risks associated with the process and without appropriate procedures to control those risks.

“As a result, when communication broke down between the pilot and vehicle driver leading to the basket tipping over, the passengers were unprepared and not in the landing position, increasing their likelihood of injury.”

This accident was the third time in Australia since 2016 where occupants of a commercial balloon have been injured during a vehicle‑assisted deflation, prompting the ATSB to issue a Safety Advisory Notice regarding the practice.

“The ATSB advises all commercial balloon operators utilising vehicle‑assisted deflation to review their current operational practices with the aim of mitigating the safety risks associated with the procedure,” Dr Godley said.

The number of large hot air balloons with envelopes of 350,000 cubic feet or greater registered in Australia has increased by around eight to nine balloons each year since mid-2015, the ATSB notes (the B-400 has a 400,000 cubic foot envelope and is certified to carry up to 22 passengers and crew).

“The average size of these larger balloons has also increased resulting in a corresponding increase in the number of passengers per balloon flight, making it likely that the number of passengers at risk of injury will also increase,” said Dr Godley.

“Regulatory guidance on the mitigation of the potential risk from vehicle-assisted deflations will be important to help educate commercial balloon operators and assist them to mitigate risk as the number of passengers in these larger balloons continues to increase.”  

The Civil Aviation Safety Authority has advised the ATSB of their intention to produce an advisory circular on deflation of hot air balloon envelopes using vehicle assistance.

Meanwhile, the operator has developed and implemented a new vehicle-assisted deflation procedure with improved communication instructions for pilots and ground crew.

Read the final report: Ground handling event involving Kavanagh B-400 Balloon, VH-LNB, near Coldstream, Victoria, on 16 March 2019

Read the ATSB's safety advisory notice: Potential for injury during vehicle-assisted deflation.

High workload likely delayed a Boeing 787 flight crew’s response to an abnormally high rate of descent while conducting an instrument landing system (ILS) approach to land at Perth Airport, prompting a ‘glideslope’ alert from the aircraft’s enhanced ground proximity warning system (EGPWS).

During the approach, the Scoot Airlines Boeing 787-9’s autopilot flight director system (AFDS) entered a degraded mode and presented the crew with information that they erroneously believed represented the glideslope. The crew followed the displayed information, which resulted in a descent below the designed approach path and the subsequent activation of the EGPWS ‘glideslope’ alert. The crew conducted a go-around, and completed an uneventful approach and landing.

An ATSB investigation into the incident found that during the approach, a disturbance of the ILS glideslope signal occurred, likely due to an aircraft taxiing for take-off in front of the glide path antenna, resulting in the 787 capturing the ILS glideslope prematurely. Because of this, the AFDS entered a degraded mode, presenting the crew with information extrapolated from a previous position, rather than updated glideslope information.

While taking actions to reset the AFDS, the crew continued descending as per the presented information, without identifying cues that indicated the information was unreliable.

The report notes the flight crew were likely experiencing higher than normal workload, due to a combination of the high speed approach and troubleshooting the unexpected glideslope indications.

This reduced the effectiveness of cockpit communication and delayed correction of the aircraft’s low altitude. This resulted in the abnormally high rate of descent, leading to descent below the designed approach path, and activation of the EGPWS glideslope alert.

The ATSB reminds flight crews that when conducting an ILS approach in visual conditions, ILS signal paths are not protected by air traffic control, and may be subject to interference. Constantly monitor the aircraft’s flight path to ensure that guidance presented to the flight crew is valid. This will also ensure that early action can be taken to correct any deviation from the approach path.

Read the final report: Flight below minimum altitude involving Boeing 787, 9V-OJC, near Perth Airport, Western Australia, on 4 December 2015

An incident where a tourism operator’s airboat struck a tree during a ‘hot lap’ as part of a wetlands tour, resulting in minor injuries to passengers and the driver, emphasises the importance of risk assessments and safety management systems, a new ATSB reports says.

The airboat Gale Force, with a driver and four passengers onboard, was operating a ‘hot lap’ as part of a wetlands tour of Sweets Lagoon, about 55 km south-west of Darwin, on 22 June 2019.

A few minutes into the tour, the airboat was at speed when the track into a turn to starboard was slightly misjudged and control was lost. The airboat’s stern swung to port and left the channel. The starboard aft corner of the airboat swung round and struck a tree a few metres from the water’s edge.

The impact threw the occupants backwards and then, as momentum swung the bow round, they were propelled forward, out of their seats. The skipper was injured and dazed from being thrown against the airboat side cage. The passengers sustained varying degrees of injury, including cuts and bruising, depending on where they were seated.

The ATSB investigation into the incident identified that operational limitations, such as speed, which would have reduced the likelihood of the collision and resultant injuries, were not fully identified by the operator’s risk assessments and therefore unable to be implemented through their safety management system following a shift in the operator’s focus away from ‘adrenaline‑based’ activity such as ‘hot laps’. 

“Tourism operators who undertake activities such as airboating that involve fare-paying passengers should carefully and regularly assess their operations for risk,” said ATSB Director Transport Safety Stuart Macleod.

“In this instance, operational limitations which would have reduced the likelihood of the collision and reduced the injury consequences had not been fully identified and implemented.”

Since the incident the airboat operator has updated its safety management system’s procedures and requirements. Specific airboat training, guidance and competency requirements have been implemented, and emergency procedures have been updated.

Read the final report: Collision with a tree involving the airboat Gale Force, Sweets Lagoon, Northern Territory, on 22 June 2019

A Cessna Caravan floatplane operating a scenic charter flight over the Great Barrier Reef clipped trees and impacted dense scrubland while attempting to go-around after an aborted water landing, a new ATSB investigation report details.

The aircraft, with a pilot and 10 passengers on board, was attempting a landing at Whitsunday Island’s Chance Bay on 28 January 2016 when it bounced three times on the water’s surface, after the pilot reported holding off the landing in order to fly through an observed wind gust. After the second bounce, with the aircraft nearing the beach, the pilot increased engine power and initiated a go-around. A more pronounced third bounce, which occurred almost immediately after the second, resulted in the aircraft rebounding about 30 to 50 feet above the water.

While increasing power, the pilot perceived that the engine torque was indicating red, suggesting an engine over-torque for the selected propeller configuration. Noticing that the climb performance was less than expected with the flaps at the 30-degree setting, the pilot stopped increasing power and reduced the flap to 20 degrees.

As it climbed straight ahead towards a saddle, the aircraft’s climb performance was still below the pilot’s expectations. Assessing that the aircraft would not clear the surrounding rising terrain, the pilot turned right. However, during the turn the aircraft clipped trees before coming to rest in dense scrub about 150 metres from the eastern end of the main beach, near the top of a ridge.

Variable water conditions and the possibility of sharing the landing area with marine vessels means that every water landing has the potential to be markedly different.

The pilot promptly advised the passengers to exit and move away from the aircraft. Some of the passengers suffered minor injuries in the accident, but all were able to leave the aircraft quickly. There was no post-impact fire, but the aircraft was substantially damaged.

The ATSB’s investigation found that the aircraft’s initial contacts with the water were past the pilot’s nominated decision point and beyond the northern boundary of the water landing area. This, combined with the delay in initiating the go-around, reduced the options and margins available for a safe outcome.

“Variable water conditions and the possibility of sharing the landing area with marine vessels means that every water landing has the potential to be markedly different,” ATSB Director Transport Safety Stuart Macleod said.

“In this case, despite the perceptions of over-torque, the pilot initiated a go-around without using all available power and the optimal speed, turned towards higher terrain, and placed the aircraft in a down-wind situation, which ultimately resulted in the collision with terrain.”

Mr Macleod said a go-around is standard practice and is typically a safe option whenever landing conditions are not satisfactory.

“However, it is important that pilots consider aircraft performance and local conditions when planning an exit route, including conducting mental rehearsals of standard procedures.”

The investigation also found that the engine operating limitations detailed in the float manufacturer’s pilot operating handbook supplement were not consistent with other guidance and may have influenced the power level applied by the pilot during the go-around.

The investigation also noted that the aircraft was equipped with lap-sash seatbelts, which have been demonstrated to reduce injury, while the use of emergency beacons and satellite phone facilitated a timely response to the accident.

Read the final report: Collision with terrain involving Cessna 208 Caravan, VH-WTY, 11 km north-east of Hamilton Island Airport, Queensland, on 28 January 2016

A catamaran ferry crew’s response to a suspected engine room fire reinforces the importance of vessel operators having robust procedures and training, a new ATSB investigation has stressed.

On 29 March 2019, the catamaran ferry Fitzroy Flyer was on a scheduled transfer between Cairns and Fitzroy Island, with four crewmembers and 37 passengers on board. About halfway into the 50-minute journey, at about 2:10pm, the port main engine overheated, activating a fire alarm on the bridge.

A crewmember and a passenger (who was a former firefighter) investigated and reported sighting smoke and fire. Initial attempts were made to extinguish the fire using portable extinguishers, but the crew could not confirm if those attempts were successful in extinguishing any fire. The presence of a fire was unable to be confirmed and, after taking advice from shore management, the master subsequently activated the port engine room fire suppression system.

Meanwhile, all passengers were mustered to the bow of the vessel, and were subsequently evacuated onto two nearby vessels. The master then started the starboard engine and the Fitzroy Flyer slowly returned to Cairns, where it safely berthed without further incident.

Inspections carried out after the incident found no evidence of a fire or any fire damage in the engine room. Instead, the smoke and fire seen by the crew were likely from a loose and slipping fan drive belt and steam from the overheated cooling system.

The ATSB found that the crew’s response to the fire alarm did not follow company procedures as they had practised during emergency drills. This included not promptly activating the vessel’s fire suppression system or applying boundary cooling, and making several entries to the port main engine room without suitable risk controls in place.

In addition, the passengers were transferred in open waters and without lifejackets to two other vessels with varying freeboards, at which point the engine room situation appeared to be under control, while the crew did not issue a ‘PAN PAN’ urgency message to emergency services and other vessels, informing of the Fitzroy Flyer’s status and requesting assistance.

“This occurrence highlights the importance of vessel operators having robust procedures and training for responding to fires and other emergencies on board, and for crewmembers to follow procedures and training in such situations,” said ATSB Director Transport Safety Dr Mike Walker.

“In particular, if a fire is suspected in an engine room, and further assessment is not possible, then crews should deploy the available suppression systems and transmit an urgency message.”

Since the incident, the Fitzroy Flyer’s owner-operator has updated the vessel’s safety management system, improved crewmember training, and installed a closed-circuit television camera surveillance system throughout the vessel.

Read the final report: Suspected engine room fire and passenger evacuation involving domestic commercial vessel Fitzroy Flyer, 13km east-north-east of Cairns, Queensland, on 29 March 2019

Checklists are essential for overcoming memory limitations and ensuring actions items are completed, an ATSB investigation into an incident where a tail strut was not detached from a BAe 146 freighter aircraft prior to take-off highlights.

The Cobham Aviation Services British Aerospace 146-300 had landed in Sydney in the early morning of 22 January 2019 while en route from Melbourne to Brisbane, conducting a scheduled night freight operation. The tail strut, which prevents the aircraft from tipping onto its rear fuselage during loading operations, was attached to the rear of the aircraft before cargo unloading and loading commenced.

Although confirmation of the tail strut’s removal prior to departure was a checklist item prior to engine start, the aircraft taxied for departure to Brisbane with the tail strut still attached. As it taxied, a ground crew member saw that the tail strut was still attached, however, a number of attempts to contact the flight crew were unsuccessful and the aircraft turned onto the runway and departed.

As a consequence the tail strut detached from the aircraft during the take-off roll and fell onto the runway. A subsequent runway inspection recovered the tail strut, and the aircraft continued to Brisbane and landed without further incident.

The ATSB’s investigation into the incident found that pre-departure checklist items, required to be performed by the aircraft captain and the ground engineer in a challenge-and-response manner, were not completed. This negated the value of the checklist as a risk control, and resulted in a missed opportunity to detect the tail strut’s presence prior to departure.

The ATSB also found that the engineer performing the aircraft turn-around had no effective means or procedure to contact the aircraft while it was taxiing.

In response to the incident, the operator undertook a number of actions including issuing a safety alert to relevant staff highlighting the despatch procedure, including the challenge-and-response requirement for the relevant cockpit to ground checklist.  

This investigation’s safety message highlights checklists are an essential tool for overcoming memory limitations, and ensuring that action items are completed in sequence and without omission.

The ATSB notes that while, the value of checklists may not be obvious for routinely-performed tasks, the incomplete use of checklists has often been cited as a factor in previous aircraft accidents.

Read the final report: Aircraft preparation occurrence involving BAe 146 300, VH-NJZ, Sydney Airport, New South Wales, on 22 January 2019

An Airbus A330 departed Sydney with the aircraft’s maximum take-off weight exceeded by 494 kg following a loading irregularity, an ATSB investigation details.

On 17 December 2017, a Qantas A330-300 was being loaded with freight in preparation for an international passenger flight from Sydney to Beijing, China. After landing in Beijing, the airline’s freight agent identified that the aircraft had been loaded incorrectly. As a result, the aircraft had departed Sydney 875 kg above the weight listed in the revised load sheet, and 494 kg above the aircraft's maximum take-off weight.

The ATSB found that an operational requirement for additional holding fuel resulted in the operating flight crew issuing a revised load instruction to carry less cargo. However, this instruction was not actioned and led to a 2,005 kg pallet of freight remaining on board the aircraft, instead of being replaced with a lighter unit weighing 1,130 kg.

The required cargo variation was not actioned by the load supervisor, as electronic messages associated with the revised loading instruction were acknowledged without being correctly interpreted. That action was probably influenced by the supervisor’s experience that load changes were accompanied by verbal advice, which did not occur on this occasion.

The ATSB’s investigation into the incident highlights the importance of communication between all parties responsible for aircraft loading. Planning and loading of freight in the high-capacity passenger sector is often conducted under significant time pressure, where delays can lead to scheduling issues.

Effective communication between all parties responsible for aircraft loading can assist in reducing errors, the investigation notes.

As a result of this, and other freight loading occurrences, Qantas have introduced handheld scanning devices that automate much of the freight confirmation and mobile communication process using printed barcode and scanning technology. The scanners were implemented at most domestic and international Qantas ports by June 2019.

Read the final report: Aircraft loading-related occurrence involving Airbus A330-303, VH-QPD, Sydney Airport, New South Wales, on 17 December 2017

The pilot of a Yakovlev YAK 9 warbird which entered a low altitude spin before impacting the ground had not previously conducted aerobatics in the aircraft and so was unlikely to be aware of its unique handling characteristics, an ATSB investigation into the accident has found.

The investigation report details that the pilot, prior to undertaking a planned instructional flight with an instructor in the YAK 9* later that afternoon, took off from Latrobe Regional Airport, Victoria shortly after 2:20pm on 7 September 2018 for a local private flight.

Data from the nearby East Sale RAAF Base air traffic control radar showed the aircraft tracked first to the south-west, maintaining runway heading, before turning north-west. North of the town of Moe, at an altitude of about 2,800 feet above sea level, the pilot began to conduct what witnesses on the ground described as aerobatic manoeuvers.

The pilot was endorsed for aerobatic manoeuvres completed by 3,000 feet above ground level but had not previously conducted aerobatics in the YAK 9.

With limited experience and recency in flying the YAK 9, the pilot was likely unaware of the aircraft’s unique handling characteristics during aerobatic manoeuvres or spin recovery.

One witness described observing the aircraft perform what appeared to be a roll followed by a loop. The aircraft came out of the bottom of the loop and made an abrupt left turn before spiralling towards the ground. Video taken by another witness showed the aircraft in a spinning, steep nose‑down attitude prior to disappearing from view.

The aircraft was found to have impacted the ground in a paddock about 3 km north of Moe, in a flat, slightly right‑wing and nose-low attitude consistent with an aircraft established in, or recovering from, a spin. The pilot was fatally injured and the aircraft destroyed.

ATSB Transport Safety Director Stuart Macleod said the accident highlights the risks inherent with performing low-level aerobatics in high performance aircraft.

“High‑performance aircraft like the YAK 9 transition into a fully developed spin quicker and more forcefully than a typical light training aircraft. It is essential to have sufficient altitude to effectively recover from a spin,” he said.

“Experienced YAK 9 pilots stated that, depending on pilot experience, 5,000 to 7,000 feet is required to safely recover the aircraft from a developed spin.

The report notes, unlike in most other warbird aircraft, as the airspeed increases during a high-speed dive recovery, in the YAK 9 the effort required to pull back on the control stick reduces. 

“This investigation reinforces to pilots performing low-level aerobatics the importance of observing minimum approved operating heights, commensurate with their ability and qualifications, and to engage in regular flight reviews and instruction.”  

The investigation report notes the pilot had conducted aerobatics in a number of warbird aircraft but only had between five and six hours of flying experience in the YAK 9, and that the accident flight was the pilot’s first in the aircraft in three months.

“With limited experience and recency in flying the YAK 9, the pilot was likely unaware of the aircraft’s unique handling characteristics during aerobatic manoeuvres or spin recovery,” Mr Macleod said.  

The ATSB investigation also identified a number of safety issues that while they did not directly contribute to the accident flight, increased risk.

For example, the aircraft’s canopy had been opened intentionally in flight the previous day, resulting in the loss of documentation from the aircraft including the aircraft checklist, flight manual and maintenance release.

“Pilots need to ensure that careful preparation and planning is undertaken prior to each flight and that all documentation, checklists and required manuals are appropriately stored and accessible within the aircraft,” Mr Macleod said.

In addition, post-accident examination of the aircraft identified incomplete maintenance practices, including inadequate airframe anti‑corrosion measures and insecure primary flight controls and seat fasteners.

* The YAK-9 was a Russian-designed single-seat fighter aircraft used during the Second World War, similar in performance to the Spitfire and P-51 Mustang. The accident aircraft, a YAK-9 UM, was a replica of the original design, built in the 1990s and fitted with two seats and an American-built, rather than Russian, engine.
 

Read the final report: Loss of control and collision with terrain involving YAK-9UM, VH-YIX, 19 km west-north-west of Latrobe Regional Airport, Victoria, on 7 September 2018

The derailment of two freight wagons and the subsequent disruption to freight and passenger services has highlighted the importance of inspection techniques that effectively monitor and report on asset condition.

On 7 June 2019, Pacific National freight train 6CM3 was operating between Griffith, in New South Wales’ Riverina region and Melbourne’s Appleton Dock. A roll-by inspection from the Down platform at Junee station detected that the 40th and 41st wagons of the train had derailed.

The investigation, conducted on behalf of the ATSB by NSW’s Office of Transport Safety Investigation (OTSI), found that the wagons had derailed at a broken rail about 300 metres before the platform. The rail had broken in two places, allowing the wagons’ wheels to derail, damaging the wagons and infrastructure.

The investigation found that, following a change in maintenance practices, rails forming turnouts between main lines were not being ultrasonically tested. As a consequence, a likely detectable rail defect went undetected, with the two rail breaks occurring at different times.

The crew’s detection of the derailed wagons prevented an escalation of the occurrence.

As a result of the incident, the Australian Rail Track Corporation identified rails forming turnouts that were not previously subjected to ultrasonic testing. Those rails were included in the asset management register, and testing was scheduled.

The investigation’s safety message highlights that managers of rail infrastructure should ensure that inspection techniques effectively monitor and report on asset condition.

Further, risk controls should be continuously assessed through the life cycle of the asset, in particular when changes are made to inspection regimes.

Read the final report: Derailment of freight train 6CM3, Junee, New South Wales, on 7 June 2019