Safety summary

What happened

On 10 February 2015, a Public Transport Authority (PTA) maintenance crew commenced work at Meadow Street, Guildford, Western Australia. The crew’s assigned tasks included maintaining the pedestrian gates adjacent to the level crossing.

At about 1035 one of the track workers was struck by a Perth-bound suburban passenger train. The track worker sustained fatal injuries.

What the ATSB found

The ATSB investigation found that the PTA maintenance workers had not implemented any form of track worker protection at the work site. This was partially due to the PTA not having documented instructions specifying the level of protection required, preferring that track workers make their own assessment based on their knowledge of the Network Rules. The ATSB found that, under these arrangements, track workers could make an incorrect assessment, placing themselves at a greater risk of being struck by a train.

A review of the safeworking training provided to the track workers found that the training material did provide a suitable level of safe-working knowledge.

Following the occurrence, the toxicology report on the deceased track worker identified the presence of amphetamine and methamphetamine; methamphetamine being a prescribed drug under the Rail Safety Regulations 2011. The use of stimulants such as methamphetamine is associated with a range of neurocognitive effects in humans that may affect performance.

The ATSB found that in this instance, the presence of a prescribed drug within the worker’s system appeared to be a relatively isolated case. An examination of the company’s drug and alcohol policy / procedures found them to be generally effective in managing drugs and alcohol in the workplace.

What's been done as a result

The PTA issued a safety alert following the incident to highlight the importance of implementing the correct level of track worker protection. The subsequent introduction of new safeworking rules, track access accreditation levels and training further supported this.

Further, the PTA has created the role of Workplace trainer and assessor with the task of ensuring track workers comply with the network rules by way of competency-based assessments. Implementation of a new track access accreditation system, with improved training and job mentoring, has also commenced.

Safety message

This incident strongly emphasises the need for rail transport operators to provide clear and concise work instructions to employees working within the railway corridor. It also highlights the potential for recreational and other drug use to impair performance and affect workplace safety.

Meadow Street pedestrian gate

Source: ATSB

The occurrence

On the morning of 10 February 2015, Public Transport Authority of Western Australia (PTA) signal maintenance crews commenced duty at Claisebrook depot. The crews were arranged into teams according to their qualification and skill sets. One of these teams consisted of a PTA employee and two contractors. The PTA employee was a maintainer, but on this day, he was undertaking the role of the protection officer^[1] to provide safe working protection to the contractors. One of the contractors, who had more experience on the PTA network, was assigned the role of signal technician while the other was allocated maintenance duties.

At about 0830, the team departed Claisebrook depot and drove to the Meadow Street level crossing in Guildford, WA. On arrival, the protection officer contacted train control and booked on-track^[2]. The team then commenced work, where the protection officer cleaned and maintained the pedestrian gates while the signal technician and maintainer carried out electrical testing.

At about 1019, down^[3] suburban passenger service 9571 approached the Meadow Street level crossing from the west. When the level crossing protection equipment (gates, lights and bells) activated, the maintainer noticed the north-west pedestrian gate was not closing completely. He advised the signal technician who, as train 9571 passed through the crossing, called the protection officer over to help assess whether the pedestrian gate needed adjusting.

Figure 1: Location map – Meadow Street level crossing, Guildford

At about 1032, train 9573 approached the Meadow Street level crossing from the west (Figure 1). The team, after again observing the operation of the pedestrian gate, decided to compare the control arm settings with the south-west pedestrian gate control arm. After train 9573 had passed through the crossing, the protection officer and the maintainer crossed the railway to the south-west pedestrian gate while the signal technician returned to the electrical location case. The level crossing protection equipment continued to operate because another train (9572) was approaching the crossing from the east, although it could not yet be seen. The maintainer mentioned to the protection officer that there was another train coming, which the protection officer acknowledged.

The protection officer and maintainer examined the south-west pedestrian gate control arm and agreed its adjustment was different to the north-west pedestrian gate. Meanwhile, up suburban passenger service 9572 continued to approach from the east. The driver of 9572 sounded the horn on approach to Meadow Street and noticed two people working on the track side of the pedestrian gates.

Moments later, the protection officer turned to his right, facing away from train 9572, and started to walk towards the track. The maintainer, who saw the train approaching the level crossing, called out a warning and attempted to stop the protection officer. The driver of 9572 saw the protection officer step towards the track and immediately made an emergency brake application.

At approximately 1035, as it passed through the crossing, train 9572 struck and fatally injured the protection officer – coming to a stop a short distance further along the track. The signal technician (at the location case) heard the collision and called out to the maintainer, who replied that the protection officer had been hit by the train.

Post-occurrence

The signal technician and maintainer immediately returned to their vehicle and contacted their supervisor. At the same time, the driver of 9572 contacted train control and advised he had struck a person at the Meadow Street level crossing.

All train services between Bassendean and Midland were suspended and the level crossing closed to traffic. The PTA, emergency services, WA Office of Rail Safety (ORS) and Worksafe WA attended the site.

At about 1200, the signal technician and maintainer were taken back to Claisebrook depot. Drug and alcohol testing was conducted – returning negative results.

At about 1300, train 9572 was moved to the Claisebrook depot for examination.

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1. Protection Officer is a nationally recognised term to describe a person who provides worksite protection (RISSB Glossary of Railway Terminology 2010) and is used in that context throughout this report. At the time of this incident, a worker who held WPW15 accreditation was responsible for worksite protection, though the term Protection Officer was not used. As of 1 August 2015, the PTA introduced protection officer qualifications, which included additional safeworking training beyond that previously supplied under a WPW15 accreditation.
2. Industry term used to describe contacting train control and advising them of the works to be undertaken at that location
3. Trains on the Midland line travelling away from Perth are referred to as ‘down’ trains, travelling towards Perth as ‘up’ trains

Context

Location

Meadow Street level crossing is located in Guildford, Western Australia, about 13 km from Perth Railway Station. The level crossing consists of dual-gauge double-track railway over a dual carriageway road with pedestrian walkways on both sides. The crossing is immediately adjacent to the road intersection between Meadow Street and James Street. The road intersection is controlled by traffic lights, which work in conjunction with the level crossing equipment.

The PTA maintained the level crossing and associated pedestrian gates.

Track information

The track at Meadow Street was part of the dual-gauge line from Midland to East Perth; consisting of both narrow gauge (1067 mm) and standard gauge track (1435 mm) using a common rail. The track in this area was part of the Australian Defined Interstate Rail Network (DIRN).

The level crossing was equipped with boom gates, flashing warning lights and bells for road traffic. The pedestrian walkway included automatic gates and electronic alarms for pedestrian traffic, with a pedestrian escape route in the event that the gates closed while pedestrians were still crossing the track.

The Meadow Street level crossing used electronic approach and outer approach track circuits to detect the approach of trains from either direction on either line (Figure 2). When a train is detected on the approach, the control circuit causes the level crossing bells and lights to activate, and the boom gates to lower. In addition, the automatic pedestrian gates close and the pedestrian alarms sound. Due to the proximity to the James Street intersection, an indication is provided to the road traffic light control system to manage any traffic intending to turn into Meadow Street.

The purpose of the outer approach circuits is to prevent the level crossing boom gates from rising and descending in quick succession if a second train is approaching the crossing. If the level crossing equipment is already operating and a train detected on the outer approach, the boom gates remain lowered and the pedestrian gates remain closed until the second train has passed.

Figure 2: Diagram of Meadow Street level crossing, Guildford, WA

The level crossing bells and lights operate when trains are detected on the approach track circuits (shown in green). If the crossing is already operating, it will continue to operate if another train is detected on either the approach track circuits or the outer approach track circuits (shown in blue). Source: PTA amended and annotated by ATSB

Train information

The PTA operates two types of electric multiple-unit (EMU) railcars. The A-series EMUs (as involved in this incident) are comprised of two semi-permanently coupled railcars, which are 48.42 m in length and have a gross weight of 114 t. The railcars’ maximum operating speed was 110 km/h.

Train services 9572 and 9573 were suburban services, stopping at all stations and operating between Perth and Midland.

Event recorders

The A-series railcars were fitted with an Automatic Train Protection (ATP) system to reduce the risk of train drivers passing a signal at danger / stop. The system also provided digital recordings of train performance such as braking, power applied, speed, etc. However, the A-series were not fitted with dedicated event recorders. In addition to the performance elements described above, an event recorder typically records operation of other mechanical and control systems such as the horn; providing important information to aid in the analysis of a safety occurrence.

Train crew information

Train 9572 was operated by a single driver. At the time of the incident the driver was appropriately qualified and trained to operate A-series railcars over the Perth - Midland route.

Following the incident the driver was tested for the presence of alcohol and other drugs and the results were negative.

Maintenance team information

The signals maintenance team working at Meadow Street consisted of:

• a PTA employee who was qualified in worksite protection and was working as the protection officer
• a contractor qualified and working as a signal technician
• a second contractor with qualifications of a signal technician but working as a maintainer.

All personnel had a safe working qualification allowing them to work within the rail reserve without supervision. The PTA employee (protection officer) had additional safe-working qualifications allowing him to provide worksite protection associated with working on or about the railway reserve.

Drug and Alcohol testing

Following the incident, the signal technician and maintainer underwent preliminary screening for the presence of alcohol and prescribed drugs. Both tests returned a negative result.

As part of the coronial investigation into the accident, a toxicology examination was undertaken on the deceased worker. The examination was unable to confirm the presence of alcohol, but amphetamine and methamphetamine were present in the samples tested. Methamphetamine is classed as a prescribed drug under the Rail Safety Regulations 2011 - the legislation applicable to the PTA’s operations at the time of the incident.

Environmental conditions

A weather report from Perth Airport (approximately 4km south of Meadow Street) showed the temperature at the time of the accident was about 27 degrees, with fine conditions and light winds.

As such, weather conditions were considered unlikely to have contributed to the occurrence.

Maintenance Tasks

The track workers’ task was to undertake maintenance of the level crossing and pedestrian gates at Meadow St. The signal technician and maintainer carried out electrical checks, while the protection officer conducted maintenance on the boom gates and pedestrian gates.

Pedestrian Gates

To facilitate maintenance of the level crossing equipment, certain tasks required the crossing to be operating while the work is being carried out. This work included tasks such as circuit testing and checks of the boom and pedestrian gate operation. In some cases, these tasks required the signal technician or maintainer to work close to or inside the danger zone^[4].

One such task was the inspection and, if required, adjustment of the pedestrian gate closing mechanism. The gate control box was located inside the pedestrian escape, with the control arm running from the box to the gate on the track side (Figure 3) - about 3 m from the railway line.

A level crossing test switch^[5] was provided at Meadow Street that can facilitate operation of the crossing equipment when trains were not present. Despite the availability of a test switch, it was common practice for maintenance personnel to rely on scheduled train services to facilitate operation of the crossing equipment for testing and maintenance of the pedestrian gates. At interview, signalling personnel reported a reluctance to use the test switch, in light of the view that it would (unnecessarily) close the crossing to road traffic. In addition, there was a slight difference in the operation of the pedestrian gates when initiated by the test switch (when gates would close under spring tension only) compared with normal operation when activated by a rail vehicle (when gates would close under a combination of spring tension and motor control).

Figure 3: General arrangement of south-western pedestrian gate

The protection officer and signal maintainer reviewed the operation of the south-western pedestrian gate from the track side of the closed gate (within the danger zone). This examination placed the track workers in a position that was less safe than being within the pedestrian escape area or on the outside of the closed gate. Source: ATSB

Maintenance personnel advised that to assess or adjust the control arm required track workers to stand inside the three-metre danger zone. Some maintainers would carry out the task with the gate open, working in the escape area with the gate acting as a barrier to the track. However, it was evident that some other maintainers carried out the task when the gate was closed, in which case there was no barrier protecting them against inadvertently stepping onto the track.

The ATSB’s investigation found that the process for conducting maintenance on level crossing pedestrian gates varied between personnel. In the subject case, the workers adopted a process whereby the presence of a train was used to operate the level crossing equipment and maintenance and/or adjustment of the gate control arm was undertaken while the gate was in the closed position. This process meant that workers would be positioned within the danger zone, and focused on the maintenance task, at a time when trains were present, and without a barrier between themselves and the track.

Worker safety and worksite protection

The safety of personnel working on and around operating rail services is achieved through a number of complementary measures. These fall into two general areas:

• Worksite protection

These are the measures put in place to mitigate the risk of injury from railway operational hazards. That is, ensuring separation between track workers and train operations.

• Worker safety

These are the measures put in place to mitigate the risk of injury from site-specific hazards and task specific hazards.

Worksite protection

To keep track workers separate from rail traffic, rail systems within Australia use various methods of safe working. The higher levels of protection involve exclusion of rail traffic from a worksite and can include the complete closure of the railway (or part thereof). The lower levels of protection permit work to be undertaken between train services and can use other employees to warn track workers of approaching rail vehicles.

Access to maintain suburban railway networks is often more restrictive than for freight networks due to the volume and frequency of rail traffic. Works that require the railway to be closed, even for a short period, are generally only undertaken at night when the frequency of rail vehicles has reduced. Works carried out during the day are usually associated with general maintenance or inspection tasks that do not require closing the railway.

The PTA Network Rules document the requirements for providing worksite protection. It is routine for track workers to use Lookout Protection when working in the danger zone with hand tools only and with the ability to move to a place of safety prior to the arrival of any oncoming rail vehicle. Rule 191 documents the requirements for lookout protection.

The purpose of lookout protection is to task a person or persons to maintain a watch for approaching trains - allowing track workers to be suitably warned to stop work, move to a place of safety and allow the train/s to pass before returning to work. The PTA network rules define a place of safety as either:

• Where there is at least 3 m clearance between the person and the nearest running line (rail);
• Properly constructed for use as a refuge;
• Where a structure or physical barrier has been erected to provide protection; or
• Behind the safety line on a platform.

Under lookout protection, the lookout’s sole duty must be to maintain a constant watch for trains and no other work^[6] may be undertaken. A lookout is only required when track workers are within, or likely to go within, the danger zone. Should the work be outside the danger zone, the lookout may perform other duties, however should track workers resume works within, or likely to go within the danger zone, the lookout must resume the exclusive lookout role.

In this occurrence, the ATSB found that the protection officer had not discussed the worksite protection method with the train controller or the contractors prior to commencing work. It was evident that the role of a lookout had not been allocated, as all three track workers continued to be engaged in maintenance tasks. At the time of the collision, the protection officer was involved with maintenance tasks rather than the assigned role of protection officer.

Worker safety

The PTA had implemented two levels of hazard assessment to ensure worker safety.

• Job Safety Analysis (JSA) forms

Job Safety Analysis (JSA) forms were used to document and assess the risks inherent to conducting the particular job at hand. The JSA for Maintenance of Automatic Pedestrian Crossing Equipment provided information such as the number of people required to carry out the job, equipment and training required, and a risk matrix containing a selection of high level generic risks that should be considered prior to commencing the job.

In the context of this incident, the JSA identified ‘Being hit by a train’ as a potential hazard, with the associated controls identified as ‘Adherence to safety procedures - assign competent lookout, obtain prior train information (booking on-track)’.

• Pre-start checklist

Pre-start checklists were used as a record that workers had considered all issues that ensure a task could be undertaken safely. The checklist is a generic form that can be used for any site or task and records information such as date, location, task and names of workers. The checklist records acknowledgment that workers have considered and understand the scope of work and the measures required to undertake the work safely, such as the information contained in the JSA.

The ATSB found that the site team, in this case, had not completed the pre-start checklist prior to commencing work at Meadow Street. While it is likely that the workers were aware of the JSA for pedestrian gate maintenance, there was no record that they had considered the worker safety risk controls contained in it.

Training

To work within the rail corridor^[7] on a railway within Australia, operators and infrastructure owners mandate that personnel are trained and deemed competent in a suitable level of safeworking. The level of training and associated competency assessments, depend on the tasks that the person is expected to carry out. Operators and infrastructure owners typically include training as part of their safety management system.

The PTA network rules stated that all persons require an appropriate Track Access Permit, before entering the PTA railway reserve to undertake work at, or closer than 3 metres from the nearest running line or overhead traction power equipment.

The PTA Appendix to the Network Rules detailed the typical accreditation level required for various position types. The appendix considers a WPW15 accreditation level for the positions of safe-working technician, electrical fitter / maintainer, as well as track supervisor and / or flag attendant as a minimum. The document Instructions to Staff Engaged on Maintenance of Signalling Apparatus also stated that a signal technician must be in possession of a PTA accreditation permit to the WPW15 level.

A simplified safe-working accreditation, designated WPW05, was also available for personnel such as managers, engineers, trades, and technical people working within the rail corridor. However, the PTA rules, instructions and training material all specified that any person undertaking work on the track or associated infrastructure must have, as a minimum, an accreditation level of WPW15. A person with WPW15 accreditation must supervise a person who only has a WPW05 accreditation when that person carries out work.

To obtain accreditation for the PTA network, workers must complete specified individual courses pertaining to the accreditation level. A WPW15 accreditation required a worker to complete courses in Working on or around the Railway Track, Safety Instructions for the electrified area and Work Site Protection. The course Awareness for unaccompanied access to worksite provides the majority of the training, which includes a section on how act as a flagman when using Lookout Protection.

In this case, the protection officer had been trained (August 2012) and deemed competent at accreditation level WPW15. The signal maintainer and signal technician both had a WPW05 accreditation at the time of the incident, although the maintainer had completed the necessary training for WPW15 accreditation during the previous week.

It is unclear whether the PTA classifies maintenance on signalling equipment as ‘work on track’ or ‘work on associated infrastructure’. Whilst the work being carried out at Meadow St was predominately undertaken more than 3 m from the track, it is reasonable to consider any work involving signalling equipment is, of its nature, work on associated infrastructure.

Since this incident, the PTA has introduced a new system of safe-working accreditation. This system has removed the WPW05 accreditation level; replacing it with a more rigid tier-based process. The theory-based training will also comprise coaching and on-the-job mentoring, which will form part of the assessment of an employee’s competency. Under the new accreditation system, track workers will gain a greater understanding of track protection implementation and operation. The PTA was also planning to internalise safe-working training for all those who work on track, rather than using an external provider. This will provide the ability to monitor and control the quality of training and assessment provided to all workers including contractors. 

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4. Industry term generally considered everywhere within 3m horizontally from the nearest rail and any distance above or below this 3 m, unless a safe place exists or has been created.
5. Also known as a flagman switch or manual switch. Used for manually activating the level crossing.
6. Work is generally defined as any activity within the danger zone other than walking directly from one side of the rail reserve to the other.
7. Also known as the rail reserve

Findings

From the evidence available, the following findings are made with respect to the fatality at Guildford, Western Australia on 10 February 2015. These findings should not be read as apportioning blame or liability to any particular organisation or individual.

Safety issues, or system problems, are highlighted in bold to emphasise their importance. A safety issue is an event or condition that increases safety risk and (a) can reasonably be regarded as having the potential to adversely affect the safety of future operations, and (b) is a characteristic of an organisation or a system, rather than a characteristic of a specific individual, or characteristic of an operating environment at a specific point in time.

Contributing factors

• Worksite protection had not been adequately implemented to ensure workers were protected against inadvertently stepping into the path of a train while undertaking maintenance work.
• When maintaining automatic pedestrian crossing equipment, it was common practice for maintenance personnel to adopt a process that was inherently less safe than an alternative.
• The Public Transport Authority of Western Australia did not have documented instructions to ensure a consistent and safe approach to maintaining automatic pedestrian crossing equipment. [Safety issue]

Other Safety Factor

• The Protection Officer tested positive to a substance that may impair performance, however it was not possible to determine whether this contributed to the incident.

Other findings

• The Public Transport Authority’s Alcohol and Other Drug policy was found to be comprehensive and compliant with legislative requirements
• The Public Transport Authority A-series rail cars do not have a dedicated system that records events such as the sounding of the horn.

Safety issues and actions

The safety issues identified during this investigation are listed in the Findings and Safety issues and actions sections of this report. The Australian Transport Safety Bureau (ATSB) expects that all safety issues identified by the investigation should be addressed by the relevant organisation(s). In addressing those issues, the ATSB prefers to encourage relevant organisation(s) to proactively initiate safety action, rather than to issue formal safety recommendations or safety advisory notices.

Depending on the level of risk of the safety issue, the extent of corrective action taken by the relevant organisation, or the desirability of directing a broad safety message to the rail industry, the ATSB may issue safety recommendations or safety advisory notices as part of the final report.

Documented Instructions

The Public Transport Authority of Western Australia did not have documented instructions to ensure a consistent and safe approach to maintaining automatic pedestrian crossing equipment.

Rail safety issue: RO-2015-002-SI-01

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through: identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

What happened

On 6 September 2015, the pilot of a Jabiru 120 aircraft, registered 245340 (J5340), conducted a flight from Wangaratta to Latrobe Valley Airport, Victoria. Another Jabiru aircraft (J1) had departed Wangaratta about 2 minutes before J5340, and also travelled to Latrobe Valley. At about 1540 Eastern Standard Time (EST), the pilot of J5340 broadcast on the common traffic advisory frequency (CTAF) when 10 NM to the north of the aerodrome, stating the current position of the aircraft and advising that J5340 was on descent and inbound to Latrobe Valley. The pilot of J1 had broadcast about 2 minutes earlier inbound to the airfield at 10 NM, and reported hearing the broadcast from the pilot of J5340.

Following the broadcast by the pilot of J5340, the pilot of a Cessna 172 aircraft, registered VHEOT (EOT), broadcast on the CTAF, that EOT was 10 NM from the aerodrome and inbound from the west. The pilot of EOT reported that he heard the broadcast from the pilot of J5340, who estimated his arrival time at the circuit at 1544. The pilot of EOT broadcast an estimated arrival time of 1543. The pilot of EOT reported that he then called the pilot of J5340 asking where he was, to which the pilot replied ‘north’. The pilot of EOT did not see a Jabiru aircraft at that time.

The pilot of J5340 reported that he broadcast again, when 5 NM from the airfield, advising his intention to join the circuit on a long downwind for runway 03. Then, when approaching abeam the northern threshold of the runway and on the downwind leg of the circuit, the pilot of J5340 broadcast joining downwind at circuit height for runway 03.

The pilot of J1 reported also having broadcast at 5 NM and when joining downwind, and was on late downwind when J5340 joined the circuit.

The pilot of EOT reported hearing a Jabiru aircraft broadcast joining final for runway 21, and then amending that to turn right to join on downwind for runway 03. However, both Jabiru pilots reported that at no stage did they broadcast or intend to join on final or to use runway 21.

About 15 to 20 seconds after the pilot of J5340 broadcast joining downwind, the pilot of EOT broadcast joining on a midfield crosswind leg for runway 03 (Figure 1). The pilot of J1, then on late downwind, sighted EOT and reportedly called the pilot of EOT, asking whether he had J1 in sight, and received the response ‘yes’. The pilot of J5340 then sighted EOT approaching from his left at the same height, about 300 m away, and reportedly also called asking whether the pilot of EOT had J5340 in sight. He reported that the pilot of EOT again responded ‘yes’, but the pilot of EOT later reported that he had not seen either Jabiru at that time.

The pilot of J5340 assessed that a collision with EOT was imminent, and immediately applied full power, conducted a steep climb and sharp right turn. As he levelled the aircraft off, after climbing about 200-300 ft, EOT passed directly underneath and then turned left onto downwind. The pilot of J5340 then broadcast a call to the pilot of EOT advising that he was above him and to his right and asked whether he had J5340 in sight. The pilot of EOT then sighted the Jabiru (J5340) above him to his right, and responded ‘yes’.

The pilot of EOT asked what the Jabiru (J5430) pilot’s intentions were. The pilot of J5340 responded that he would follow EOT, and extended the downwind leg to ensure adequate separation existed between the two aircraft. J1 had landed by that time, and both EOT and J5340 subsequently landed safely.

Pilot experience and comments

Pilot of VH-EOT

The pilot of EOT had recently passed his private pilot licence exam but had not yet received the associated paperwork. The pilot was conducting a navigation exercise towards the commercial pilot licence and had about 110 hours experience.

The pilot of EOT did not see J5340 until it had passed overhead. He did not see the other Jabiru (J1), or hear any broadcasts from the pilot of J1, at any time either in the air or after landing.

Pilot of Jabiru 24-5340

The pilot of Jabiru 24-5340 held a Recreational Aviation Australia licence and had approximately 700 hours experience as pilot in command.

The pilot of J5340 prefaced each broadcast with ‘Jabiru 53-40’ and the pilot of J1 also prefaced each broadcast with Jabiru and the aircraft registration number. The pilot of J1 reported that he read out each digit of the registration to make a clearer distinction between the two Jabiru aircraft.

Figure 1: Latrobe Valley Airport showing approximate aircraft tracks

Source: Google earth – annotated by the ATSB

ATSB comment

The CTAF at Latrobe Valley was not recorded, and the ATSB was unable to verify any of the reported transmissions. The pilots of both Jabiru aircraft reported hearing each other’s broadcasts as stated. The ATSB obtained radar data, however none of the aircraft operating in the area at the time were visible. The operator of EOT provided recorded flight data of the aircraft track.

Safety message

Pilots operating under the visual flight rules are required to maintain vigilance so as to see and avoid other aircraft. Civil Aviation Advisory Publication (CAAP) 166-2(1), stated:

Lookout is the principal method for implementing see-and-avoid. Effective lookout means seeing what is ‘out there’ and assessing the information that is received before making an appropriate decision.

Broadcasting on the CTAF is known as radio-alerted see-and-avoid, and assists by supporting a pilot’s visual lookout for traffic. An alerted search is more likely to be successful as knowing where to look greatly increases the chances of sighting traffic.

Following a broadcast, it is important for other pilots in the vicinity to ensure they have the aircraft sighted. Issues associated with unalerted see-and-avoid have been detailed in the ATSB research report Limitations of the See-and-Avoid Principle.

As detailed in the booklet A pilot’s guide to staying safe in the vicinity of non-towered aerodromes, ATSB research found that, between 2003 and 2008, there were 709 airspace-related events at, or in the vicinity of non-towered aerodromes. This included 60 serious incidents and six accidents (mid-air and ground collisions). Most of the 60 serious incidents were near mid-air collisions.

The ATSB investigated a mid-air collision at Latrobe Valley Airport on 1 December 2007, AO-2007-065, in which a Cessna 172 collided with an Avid aircraft on final approach to runway 09.

Aviation Short Investigations Bulletin - Issue 45

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2015 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

What happened 

On 1 September 2015, a Cessna 180C aircraft, registered VH-FDH (FDH), departed Normanton for Karumba Airport, Queensland at about 1435 Eastern Standard Time (EST). The pilot and two passengers were on board for the private flight. The aircraft had a tail wheel landing gear and the landing technique planned to be used was a wheel landing (see Landing techniques below).

At Normanton, the aircraft was refuelled and departed at almost maximum take-off weight. The aircraft climbed to about 1,000 feet for the short distance to Karumba (about 20 NM). On approaching Karumba, the pilot used the aircraft radio to contact another pilot who had just landed at Karumba to ascertain the weather conditions and to determine the most suitable runway for a landing. The pilot of the aircraft that just landed indicated to the pilot that the wind was directly across the runway from the north-west and either runway direction would be suitable for a landing. They decided to land on runway 21 (Figure 1) and joined the circuit on the downwind leg. On downwind, the windsock was observed and confirmed that the wind direction was directly across the runway from the north-west and the pilot estimated the wind speed to be about 10 knots.

Accident site of Cessna 180C, VH-FDH

Source: Carpentaria Shire Council

Figure 1: Map of Karumba Airport

Source: Google earth, modified by the ATSB

The aircraft was established in a stable final approach and the pilot determined that there was no crosswind correction required. The main wheels touched down firmly on the runway and the aircraft bounced about 3 to 4 feet. The pilot moved the control column forward slightly to stop the tail from touching the runway. The main wheels touched again at about the same time as the pilot noted that the nose started to move to the right (turning into wind). The pilot moved the aircraft controls to straighten the aircraft in line with the runway, but the aircraft did not respond to the correction. The tail continued to move quickly around (ground loop) ^[1] before the pilot could take any other action. The pilot was pushed up against the cockpit door. A very loud bang was heard as the left main landing gear failed, the left wing folded up and the fuselage tilted onto its side where the aircraft skidded a short distance to a stop. The aircraft stopped, almost pointing back in the opposite direction to the landing, partly on the grass beside the runway (Figure 2). The pilot turned off the engine magnetos, aircraft fuel, and electrical master switch. The two passengers exited the cockpit right door with the help of bystanders and then the pilot exited the same way. The pilot received minor injuries and the two passengers were uninjured. The aircraft was substantially damaged.

Figure 2: Cessna C180 FDH accident site

Source: Carpentaria Shire Council

Landing techniques

There are two landing techniques that can be used in tail wheel aircraft. A wheel landing is where the tail of the aircraft is held off the runway and the main wheels touch down first and then the tail wheel. The other landing technique used in a tail wheel aircraft is the three-point landing where the two main wheels and tail wheel touch the runway together.

Pilot training and tail wheel experience

The pilot had about 1,200 total flight hours with about 84 hours in tail wheel aircraft. The majority of landings in those tail wheel aircraft were three-point landings. The pilot commenced training in 2006 for a tail wheel endorsement, initially training in an Avions Mudry CAP 10, where only three-point landings were practiced. The pilot gained further training in an American Champion Super Decathlon, focussing on the wheel landing technique. During an aerobatics and formation endorsement in the Super Decathlon, the pilot revised both wheel and three-point landings. The pilot was also checked-out to fly an Aviat Aircraft Husky and a de Havilland Chipmunk, although reported only having a few hours in each. The pilot conducted a biannual flight review in March 2015 in a Cessna 172 (tricycle landing gear aircraft). The pilot had flown one other Cessna 180 and in that aircraft, had conducted three-point landings.

Of the pilots 84 hours in tail wheel aircraft, 30 were in a Cessna 180, and in the preceding 30 days, about 23 hours were in FDH.

Pilot comment

The flight was part of an air race and prior to the accident they had conducted about 20 hours of flying, departing Jandakot, and landing at Esperance, Forrest, Ayers Rock, Alice Springs, Davenport Downs, Winton, and Normanton. Of those landings, the pilot reported not being happy with any of the landings. The pilot indicated that this was the first landing in the aircraft that was conducted at almost the maximum landing weight and with a significant crosswind. All the other landings were with little to no crosswind component.

The pilot reported that the owner of FDH, who was also a pilot (medical not current), was extremely proficient at conducting wheel landings and wanted the pilot to conduct wheel landings in FDH. The pilot had conducted circuits with the owner about 2.5 weeks prior to the air race and recalled mentioning to the owner that they felt more comfortable conducting three-point landings.

The pilot reported that during the landing, they were very focused on keeping the aircraft straight with the runway and recovering from the bounce. On another landing in FDH where the aircraft had bounced about 3 to 4 feet, the pilot reported resolving the landing without going around.

Safety message

The US Federal Aviation Administration (FAA) discusses in their publication Airplane Flying Handbook Chapter 13 Transition to Tailwheel Airplanes the importance to land with the aircraft in the longitudinal axis exactly parallel to the direction the aircraft is moving along the runway. If the aircraft lands while in a crab or while drifting, it imposes severe side loads on the landing gear and imparts ground looping (swerving) tendencies. The handbook is available from the FAA website.

Aviation Short Investigations Bulletin - Issue 48

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

__________

1. A ground loop is an uncontrolled turn during ground operation.

What happened

On 31 August 2015, the pilot, and sole occupant, of a Schweizer 269C helicopter, registered VHJXO (JXO), was conducting aerial spraying in the Edinburgh area, South Australia, and operating under the visual flight rules (VFR). The helicopter departed from Calvin Grove aeroplane landing area (ALA) at about midday Central Standard Time (CST), and the pilot obtained a clearance from Edinburgh Airport air traffic control (ATC) to track to Virginia (Figure 1). The pilot conducted spraying operations in that area, and then requested and obtained a clearance to track to an area south of Gawler. The operations included regular take-offs and landings to refuel and reload with chemical. The pilot continued spraying operations about 3.5 NM southeast of Gawler aeroplane landing area (ALA), which was outside the Edinburgh control zone, below the 1,500 ft lower limit of restricted airspace, and therefore in Class G airspace.

Figure 1: Locations relevant to VH-JXO

Source: Google earth – annotated by the ATSB

At about 1503 CST, a Military Lockheed AP-3C aircraft (Orion) was about 15 NM northeast of Edinburgh, at 6,500 ft, tracking for the runway 18 instrument landing system (ILS) –Y approach to Edinburgh Airport. The Orion, with 5 crewmembers and 14 passengers on board, had departed about 10 hours earlier on an international flight bound for Edinburgh, and was operating under the instrument flight rules (IFR).^[1] The weather conditions at Edinburgh at the time, included no cloud below 5,000 ft and visibility greater than 10 km.

At about 1504, the pilot of JXO called Edinburgh Tower air traffic control, and requested a clearance to track to ‘Clare’ (Clare Valley), South Australia. In order to track direct to Clare Valley, which was about 45 NM to the north-northwest, the pilot needed a clearance through a corner of the Edinburgh control zone (Figure 2).

Figure 2: Operating area of JXO, Edinburgh Control Zone and relative tracks

Source: Airservices Australia – annotated by the ATSB

The tower (TWR) controller 1, mistook the pilot’s request to ‘Clare’ for ‘Calvin Grove’, and cleared the pilot of JXO to track direct to Edinburgh Tower, not above 1,000 ft in order to be able to visually separate the helicopter with the arriving Orion and another aircraft conducting circuit operations at the airfield. The pilot complied with the instruction, even though this was not the direction requested, nor the clearance expected. However, being new to the area and concerned about the direction of the clearance, the pilot attempted, unsuccessfully, to contact their company via UHF radio to ask for advice.

At about 1506, the TWR controller 1 completed their shift and conducted a handover to tower (TWR) controller 2. The TWR controller 1 advised TWR controller 2 of JXO, tracking to the tower then for Calvin Grove, and stating that they planned to track JXO ‘over the top’ (of the airfield) to separate with the Orion and could hold JXO if necessary, depending on the requirements of the aircraft conducting circuits. About 2 minutes later, the crew of the Orion reported established on the ILS.

At about 1509, when about 5 NM from the tower, the pilot of JXO reported the helicopter’s position to the tower controller, hoping to prompt the controller for a clearance towards Clare Valley, but the TWR controller 2 directed the pilot to continue tracking direct to the control tower. The pilot then again attempted to contact their company via UHF radio to seek guidance on Edinburgh operations.

About 1 minute later, the TWR controller 2 advised the aircraft conducting circuit operations at Edinburgh of both the Orion, then at 12 miles on the ILS, and JXO, as traffic, stating that JXO was for Calvin Grove. During that transmission, the pilot of JXO was trying to communicate on UHF radio and did not assimilate the information about the Orion. Soon after that transmission, the flight crew of the Orion, which was then at 9 NM, advised they were on the ILS-Y passing 3,200 ft^[2] on descent.

The circuit aircraft then turned onto base leg for runway 18, was cleared for a touch-and-go, and advised they had the (Orion) aircraft in sight.

At about 1512, the Orion was passing 2,400 ft, on a 6.5 NM final and travelling at 170 kt. JXO was at 600 ft and travelling at 60 kt (Figure 3). Based on the expected tracking of the three aircraft, the TWR controller 2 assessed that JXO would safely cross the runway centreline in front of the Orion, and behind the aircraft conducting circuits (then on a short final). Consequently, the TWR controller 2 cleared JXO to track to Calvin Grove. The pilot heard the call and responded, but the radio was still selected to transmit on UHF not VHF, so the controller did not receive a response. The pilot was flustered and expecting an onwards clearance to Clare Valley, consequently had turned right to track northwards to Clare Valley.

Figure 3: Aircraft positions when JXO was cleared to Calvin Grove (time 1512)

Source: Department of Defence – annotated by the ATSB

Having not received a response, the TWR controller 2 repeated the call to JXO, and again did not receive a response. The TWR controller 2 then made two more attempts to communicate with the pilot of JXO, including requesting a ‘radio check’, without receiving a response. The pilot of JXO could hear the calls and eventually realised they had the incorrect radio selected to transmit.

Separation Standards

According to the Manual of Air Traffic Services (MATS), separation is the concept of ensuring aircraft maintain a prescribed minimum from another aircraft (or object), while meeting the associated conditions, and requirements of the standard. A separation standard is a prescribed means to ensure separation between aircraft using longitudinal, lateral, vertical and visual standards.

Use of the Situation Data Display

Edinburgh Tower controllers did not hold approach endorsements and therefore were not able to use the radar situation data display (SDD) to vector aircraft to achieve separation. The controllers were required to achieve separation through the issue of tracking instructions, level assignment or through visual observation. The radar SDD could be used to monitor separation and achieve situational awareness.

While attempting to establish communications with JXO, the TWR controller 2 monitored JXO’s tracking using binoculars. About the time of the radio check, JXO appeared to turn right, then fluctuate between north-westerly and westerly headings. Due to the small size of JXO and its distance from the tower, its exact tracking was difficult to determine visually. Furthermore, the tower radar situation data display (SDD) did not provide a true representation of the helicopter’s tracking, due to its slow speed. The SDD did indicate that JXO had tracked further north than cleared, which increased the closure rate between the helicopter and the Orion.

At about 1513, the pilot of the Orion reported at the outer marker on the ILS (4.2 NM from the runway threshold), and the TWR controller 2 cleared the Orion to land (Figure 4). JXO was then tracking north-northwest, about 3 NM from the Orion, and converging. The TWR controller 2 was then apprehensive about JXO’s tracking. Although the crew of the Orion had heard the controller’s attempts to contact JXO, as the controller had not provided them with directed traffic information, they were unaware of JXO’s position, and assumed it was not a consideration for their tracking.

Figure 4: Orion at the outer marker (time 1513)

Source: Department of Defence – annotated by the ATSB

The TWR controller 2 then conducted another radio check with the pilot of JXO in an attempt to re-establish communications. The Orion and JXO were about 1.5 NM apart, and their flight paths were merging. On the radar SDD, JXO was indicating about 700 ft and the Orion was passing 1,100 ft on descent. The TWR controller 2 then conducted another radio check using an alternative handset, to ascertain whether the communications issue may be due to ATC equipment.

The pilot of JXO responded, apologised, advised they had the radio selected to an incorrect frequency, and that they had requested a clearance to track to Clare Valley, not Calvin Grove. During that transmission, the distance between JXO and the Orion reduced to about 1 NM laterally, and 200 ft vertically.

Immediately following the pilot of JXO’s response, the TWR controller 2 asked whether the pilot had the ‘P3’ (Orion) in sight, advising that it was then in the pilot’s 1 o’clock^[3] position at about 2 miles. The pilot queried the aircraft type, and the TWR controller 2 advised that the ‘P3 Orion’ was now at about 1 mile in the pilot’s 2 o’clock position. The pilot was initially unable to sight the Orion, as it was below, to the right, and behind the helicopter, and therefore not in the pilot’s 1 or 2 o’clock position (Figure 5). The pilot then saw the Orion’s shadow on the ground and sighted the Orion. The pilot of JXO responded having the aircraft in sight, and the TWR controller 2 directed the pilot to pass behind that aircraft.

Figure 5: Relative positions when ATC advised JXO of the Orion (time 1514)

Source: Department of Defence – annotated by the ATSB

By the time the controller completed that transmission, JXO had passed overhead the Orion. On sighting the Orion, the pilot of JXO had immediately initiated a climb to avoid a collision, and estimated the Orion passed about 100 ft below. On hearing the controller pass the Orion as traffic to the pilot of JXO, the Orion crew immediately became concerned about the helicopter’s proximity, and looked for it. The co-pilot (non-flying pilot) of the Orion sighted JXO, assessed there was a risk of collision, and called ‘go low, go low, go low’. The captain (flying pilot), also sighted JXO, and increased the rate of descent to pass beneath the helicopter. The Orion crew estimated that JXO passed about 50 ft directly above the Orion, and were concerned it may collide with the Orion’s vertical tail fin. On the radar SDD, at 1514:25, both aircraft appear in the same position at 600 ft (Figure 6).

Figure 6: Aircraft collocated on radar SDD

Source: Department of Defence – annotated by the ATSB

The Orion landed without further incident on runway 18. The pilot of JXO was subsequently cleared to depart the Edinburgh control zone tracking to Clare Valley.

Pilot comments

The pilot of JXO provided the following comments:

• The pilot could have tracked around the restricted airspace towards Clare Valley, by going via Roseworthy. The pilot was new to the area, unsure of the local landmarks, and therefore requested a clearance to track direct.
• The pilot was nervous about operating in military controlled airspace and therefore did not question the clearance to track towards the Tower, even though it was not where they wanted to go. The pilot reported feeling ‘a bit rattled’.
• The pilot had selected Clare Valley on the GPS, and was unsure exactly where Calvin Grove was from their current position. If JXO had tracked to Calvin Grove, it would have remained clear of the aircraft approaching runway 18.

Department of Defence investigation

The Department of Defence conducted an investigation and made a number of findings. Some of those findings are detailed here.

Initial airways clearance issued to JXO

The TWR controller 1 interpreted JXO’s destination as Calvin Grove. Two hours prior to the incident, the TWR controller 1 had processed JXO from Calvin Grove, thereby associating JXO with Calvin Grove. Additionally, JXO could have tracked from their location near Gawler to Clare, with only a small deviation east of Roseworthy to remain clear of the restricted airspace (see Figure 1). Therefore, the controller would not have expected a request of an airways clearance to Clare from JXO.

Communications issue

The TWR controller 2 made six attempts to re-establish two-way communications with the pilot of JXO over a period of 92 seconds. The loss of two-way communications was due to the pilot transmitting on an alternative frequency.

The loss of two-way communications with JXO meant that the TWR controller 2 was unable to pass instructions to the pilot to sight, and maintain separation with, the Orion. The attempts of the pilot of JXO to communicate with their company on UHF radio also diminished the pilot’s ability to maintain situational awareness of other traffic within the control zone from the radio calls of the circuit aircraft, the Orion crew, and the controller.

The combination of communication difficulties and clearance towards an incorrect destination, led to the pilot of JXO becoming flustered. The pilot therefore turned towards Clare instead of the cleared destination of Calvin Grove. Shortly before returning to Tower frequency, the pilot realised the last clearance issued was to Calvin Grove, and turned onto a westerly heading, thereby converging with the Orion.

Visual separation

Visual separation (MATS)Separation may be reduced in the vicinity of aerodromes when adequate separation can be provided using visual observation and each aircraft is continuously visible to the aerodrome controller.

Visual separation (MATS)
Separation may be reduced in the vicinity of aerodromes when adequate separation can be provided using visual observation and each aircraft is continuously visible to the aerodrome controller.

The TWR controller 2 assessed that sufficient time and distance existed for JXO (tracking for Calvin Grove) to cross final ahead of the Orion while maintaining the visual separation standard. However, the disparate sizes and speeds of the Orion and JXO, combined with their relative positions and distance from the control tower, made it difficult to maintain separation by visual observation.

After the Orion crew reported at the outer marker, it became apparent to the controller that visual separation would be lost. However, due to the proximity and relative tracks of the helicopter and the Orion, it was then impossible to introduce an alternative separation standard such as vertical displacement^[4] or assigning separation responsibility to the pilot.

Compromised separation recovery

In accordance with the Manual of Air Traffic Services (MATS), the Orion had a higher priority because it was operating under IFR flight rules. This influenced the TWR controller 2’s decision to allow the Orion to continue the ILS-Y approach, while attempting to communicate with JXO. However, MATS also required controllers not to compromise safety in order to meet the priorities.

The TWR controller 2 did not pass traffic information on JXO to the crew of the Orion, as the controller did not intend to assign responsibility for separation to them. The controller intended for the pilot of JXO to sight the Orion and accept responsibility for separation. Passing traffic information to the smaller aircraft on the larger aircraft conformed to the compromised separation recovery techniques taught to the controller.

The combination of incorrect application of visual separation, ATC priorities, and the decision not to amend the Orion’s tracking, led to a loss of separation between the Orion and JXO, including a loss of wake turbulence separation.

The TWR controller 2 assessed that instructing the Orion to go around from the approach would not solve the confliction, as the aircraft may not achieve sufficient climb performance to overfly JXO. The controller also assessed that the Orion crew may not safely have been able to conduct a hard right turn as the aircraft was in the landing configuration and at a critical stage of flight. The Orion flight crew later advised that a right turn manoeuvre to avoid the confliction would have been within the capabilities of the aircraft.

The TWR controller 2 did not issue a safety alert. The controller reported that they were about to issue a safety alert to the Orion crew, when the pilot of JXO returned to the Tower frequency, and made a transmission that lasted 10 seconds. At that time, the aircraft were 1.2 NM apart laterally, and 400 ft vertically. A safety alert issued at that time may have allowed the Orion crew to increase the vertical separation between the aircraft. If the controller had issued a safety alert earlier, it would have increased both lateral and vertical distances between them.

The clock positions provided to the pilot of JXO were incorrect and delayed the pilot’s ability to sight the Orion. The preferred compromised separation recovery technique is to provide a bearing and distance of the other aircraft to the pilot, which was available from the radar SDD.

Traffic collision avoidance system

The Orion is fitted with a traffic collision avoidance system (TCAS). In accordance with standard operating procedures, the crew of the Orion had selected low sensitivity mode on the TCAS when established on the ILS, and prior to contacting Edinburgh Tower. This mode provides no audible alert to the aircrew of potentially conflicting traffic. The captain and the co-pilot both observed the circuit aircraft on the TCAS display indicating that the system was functioning normally, but JXO did not appear. While JXO had a functioning transponder, the reason that it was not being displayed on the Orion’s TCAS could not be determined.

Safety action

Whether or not the ATSB identifies safety issues in the course of an investigation, relevant organisations may proactively initiate safety action in order to reduce their safety risk. The ATSB has been advised of the following proactive safety action in response to this occurrence.

Department of Defence

As a result of this occurrence, the Department of Defence advised the ATSB that they are taking a number of safety actions. These include the following:

Compromised separation recovery training

The Department of Defence has released a Standing Instruction that mandates annual compromised separation recovery training for all air traffic controllers.

Controller briefing

All controllers will be briefed on the events and findings of the incident as an element of compromised separation recovery training.

Tower simulation capability

Tower simulation capability is being introduced to enhance compromised separation recovery training.

Additionally, simulation will be used to:

• compensate for low traffic levels and to facilitate controller attainment and retention of skills associated with processing complex traffic scenarios
• compensate for low traffic levels and to facilitate controller attainment and retention of skills associated with application of ATC priorities
• assess controller proficiency when live traffic levels are below that required to judge controllers’ abilities to process complex traffic scenarios
• provide controllers with regular exposure to compromised separation recovery scenarios, to improve decision making and ensure the associated actions become instinctive.

Airspace procedure briefings

The Edinburgh controllers will provide airspace procedure briefings to pilots who conduct airwork within and around Edinburgh airspace. The Airservices Australia Aeronautical Information Publication (AIP) En Route Supplement Australia (ERSA) entry for Edinburgh will be amended to include a section detailing the requirements for pilots of civil aircraft intending to conduct airwork within, or near, the Edinburgh control zone, to have airspace briefing.

Safety message

This incident highlights the importance of communication, and demonstrates the potential consequences of a loss of communication. Whether pilots are communicating with each other, or with air traffic control, it is essential to understand what is being said and how that potentially affects them. In particular, if an instruction from air traffic control is not as expected, pilots should request clarification.

For controllers, having tactical separation assurance in place reduces the likelihood of a loss of separation, particularly in the event of communications failure.

Compromised separation recovery is a critical skill for air traffic controllers, which needs to be practiced often and in sufficiently complex scenarios to be applicable and implemented when necessary.

The Australian Transport Safety Bureau (ATSB) research report AR-2012-034 titled Loss of separation between aircraft in Australian airspace January 2008 to June 2012 found that aircraft separation is a complex operation with many levels of defences to avoid errors and safely manage the results of errors made by air traffic controllers and pilots.

Aviation Short Investigations Bulletin - Issue 45

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2015 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

__________

1. In accordance with the Manual of Air Traffic Services (MATS) para. 2.4.2.2, air traffic control is responsible for providing separation between IFR and VFR aircraft.
2. All altitudes in the report are in feet above mean sea level (AMSL). Edinburgh Airport elevation is 67 ft AMSL. The radar display shows altitude to the nearest 100 ft.
3. The clock code is used to denote the direction of an aircraft or surface feature relative to the current heading of the observer’s aircraft, expressed in terms of position on an analogue clock face. Twelve o’clock is ahead while an aircraft observed abeam to the left would be said to be at 9 o’clock.
4. The minimum vertical separation required at that time, would have been 1,000 ft.

What happened

On 1 September 2015, the pilot of a SA227 (Metroliner) aircraft, registered VH-HPE (HPE), was conducting a scheduled freight run from Brisbane, to Emerald, via Thangool Airport, Queensland.

Approaching Thangool, the pilot conducted a Distance Measuring Equipment (DME) arrival with a left circuit onto runway 28, touching down at 0545 Eastern Standard Time, just before first light.

Shortly after touchdown, and with all landing gear wheels in contact with the ground, the pilot saw the glimpse of an animal flash from left to right in front of the aircraft. At the time, the aircraft was travelling at about 80 kt. The right propeller then struck the animal, later identified as a small kangaroo. The pilot reported that following the large bang associated with the propeller striking the animal, there was a lot of vibration throughout the aircraft, but no abnormal engine indications. The pilot continued the landing roll, and used ground idle rather than reverse thrust to slow the aircraft.

The pilot taxied the aircraft to the parking bay, shut down the engines, then carried out an external inspection and found that one of the propeller blades attached to the right engine was twisted (Figure 1). The pilot was not injured.

Following the incident, the operator replaced the right engine and propeller and arranged for the original engine to be further assessed by engineering staff.

Figure 1: Damage to propeller blade on VH-HPE

Source: Pilot

Pilot experience and comments

The pilot held an Airline Transport Pilot Licence (Aeroplane) (ATPLA) and had about 4,900 flying hours, with about 1,310 hours on Metroliner aircraft. The pilot stated that there were no relevant NOTAMS for Thangool Airport, nor any alerting radio calls regarding wildlife. During the approach, the pilot had activated the pilot activated lighting (PAL), which provides runway and airport lighting, however no wildlife was evident on the runway.

Thangool Aerodrome Safety Officer comments

The aerodrome safety officer (ASO) reported that, due to continual pro-active mitigation strategies, such as animal culling, there have been no reported kangaroo strikes at the airport in the last 28 years.

The ASO also commented that they had conducted a runway inspection about 20 minutes prior to the Metroliner landing. No animals were evident during that inspection.

Banana Shire Council comments

Sections of the Thangool Airport had wildlife protective fencing however, it is not fully fenced. At the time of publication, the Banana Shire Council, who own and operate the airport, had a funding application lodged with the Australian Government’s Regional Aviation Access Programme to enable the remainder of the airport fencing to be completed (Figure 2).

Figure 2: Thangool airport with current and proposed fencing marked

Source: Banana Shire Council

Additional wildlife strike

On 2 September 2015, another kangaroo strike was reported to the ATSB (ATSB occurrence number 201503915). In this occurrence, a Raytheon B200 aircraft, VH-FDB, was on a medical retrieval mission from Townsville to Barcaldine Airport, Queensland. As the aircraft touched down in the early hours of the morning, at about 0141 EST the pilot caught a last moment glimpse of the animal before the aircraft struck a small kangaroo. The pilot reported that engine indications were normal, with no noticeable vibration as they completed the landing roll and then shut down the left engine while on the runway. They then taxied clear of the runway using the remaining engine. The strike caused damage to the three propeller blades attached to the left engine and disabled the aircraft (Figure 3)

Operator comment

The operator commented that although the Enroute Supplement Australia (ERSA) entry for Barcaldine Airport warns that both an animal and bird hazard exists, the local base had never sighted any animals, and therefore were somewhat inclined to discount it as a likely occurrence.

The operator/crew had not requested a “roo inspection” prior to the landing. They have also advised the ATSB that apart from the propeller damage, the left engine power module may also need replacing.

Figure 3: VH-FDB showing twisted propeller blades

Source: Operator

Barcaldine Regional Council

A council representative advised the ATSB, that a 6 ft chain mesh fence, with locked gates surrounded Barcaldine Airport. The airport staff conducted regular wildlife inspections at the airport, and also upon request with prior notice. They advised that due to drought conditions, there has been a noticeable increase in kangaroo numbers in the prior months. This increase was due to the animals seeking feed.

Safety action

Whether or not the ATSB identifies safety issues in the course of an investigation, relevant organisations may proactively initiate safety action in order to reduce their safety risk. The ATSB has been advised of the following proactive safety action in response to this occurrence.

Operator of VH-FDB

As a result of this occurrence, the aircraft operator of VH-FDB has advised the ATSB that they are taking the following safety actions:

Strip inspection

The operator is amending their internal procedures, to automatically request a strip inspection for animals at any airport in the ERSA where an animal hazard is listed. This new procedure will also extend to requesting a strip inspection at any aeroplane landing area (ALA) when deemed appropriate.

Safety message

Occurrences involving aircraft striking wildlife, particularly birds, are the most common occurrences reported to the ATSB. They are a significant economic risk for aerodrome and airline operators as well as a potential safety risk. The ATSB regularly publishes a statistical report on the number and frequency of wildlife strikes. The aim of the report is to give information back to pilots, aerodrome and airline operators, regulators, and other aviation industry participants to assist them with managing the risks associated with bird and animal strikes. This is available on the ATSB website.

Both animal strikes and bird strikes remain a mandatory reporting item under the Transport Safety Act 2003. Reporting obligations are available on the ATSB website.

Source: ATSB

Aviation Short Investigations Bulletin - Issue 45

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2015 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

Safety summary

What happened

On 28 August 2015, a Pacific National fully loaded coal train MB520 departed from Maules Creek, NSW destined for Port Waratah, NSW. Shortly after passing Ardglen and descending the grade towards Pages River, a wheel failure occurred on the leading right hand wheel on the 19th wagon. This led to the wheel moving off the wheel seat towards the centre of the axle. The bogie rotated causing the other wheels on the bogie to derail. The train continued travelling until a damaged inter car brake cable activated the train’s brakes. There were no injuries, but the derailment caused damage to over 590 metres of track including 963 sleepers.

What the ATSB found

The ATSB investigation found that the derailment was caused by a wheel failure. A metallurgical analysis conducted after the derailment found that the wheel had multiple cracks in the wheel rim; one crack extended from the rim to the boss of the wheel. This likely originated from a transverse thermal crack on the wheel tread surface. Thermal cracks of this type are generally associated with high thermal input under service brake conditions.

An increasing level of wayside alerts starting a month before the derailment indicated the likelihood of the fault being present then. Despite the increasing impact level readings, no immediate action was taken to inspect the wheel before it eventually failed.

It was found that the wheel inspection processes were not effective in detecting surface damage or cracks. The failed wheel was approaching the end of its service life with a rim thickness of 25 mm. This low rim thickness increases propensity to thermal distortion and is likely a significant factor into the thermal crack formation and propagation that occurred.

At the time of writing this report there have been seven reports of fractures detected in wheels, within a 3-year period, on Pacific National coal wagons in NSW. Three occurred before the derailment with the first incident on 31 May 2013. Three more fractured wheels were identified within a two-month period after the derailment. Following the first three wheel failures internal reports recommended changes to reduce the risk of wheel defects. Only limited action was taken by the operator prior to the derailment on 28 August 2015.

What's been done as a result

Since the derailment, the rollingstock operator has advised that they have established a process to remove wheels considered to be at greater risk of fracture. To this end, they have implemented a program to remove wheels with a rim thickness under 25 mm. Pacific National also intends to improve their internal standards to include revised criteria and actions for thin rims and wheel impacts.

Safety message

Rollingstock operators with heavy haul wagons using wheels near the end of their service life should be aware of the increased risk of wheel failure due to cracking. They should ensure that wheel inspection and maintenance programs include systems and techniques for detecting and assessing wheel defects with the potential to lead to cracking. These systems and techniques should be validated to ensure they are effective to detect such defects.

The occurrence

Events leading up to the occurrence

On 28 August 2015, at 0210^[1], a Pacific National train crew, comprising a driver and second person, signed on for duty at Gunnedah, NSW. They were rostered to drive Pacific National coal train MB520 from Gunnedah to Port Waratah where the coal was to be unloaded. The train had been loaded at Maules Creek and driven by another train crew to the Gunnedah loop. The original train crew waited for the replacement crew to take over.

At 0228, the driver and second person relieved the outgoing crew who reported that there were no issues with the train. Two minutes later the incoming driver entered his identification number into the leading locomotive’s computer, confirmed the headlights were on, and departed Gunnedah loop.

As the train departed the loop, the routine roll-by inspection of the train was not conducted due to concerns about the potential for other trains to be delayed. However, the outgoing second person informed the incoming crew that a roll-by inspection was conducted earlier at Emerald Hill, about 18 km away. During this inspection, no problem with the train was identified.

At 0544, the train came to a stand at Chilcotts Creek to allow bank locomotives to attach to the rear of the train.^[2] The gradient leading up to the Ardglen tunnel, a summit tunnel on the Liverpool Range, is 1 in 40 (2.5%) (Figure 1). The grade crests inside the tunnel.

Figure 1: Curve and gradient diagram for incident location

The red arrow shows the direction of travel for MB520

Source: Rail Access Corporation

The bank locomotives were attached and the train departed Chilcotts Creek at 0549. Once the train had reached the summit at Ardglen, the locomotives were detached and MB520 continued through the tunnel. The train exited the tunnel at 0612, travelling at 19 km/h.

The occurrence

As the train was descending towards Pangela at 24 km/h, the front right wheel (R4) failed on the 19th wagon (NHIH97081). This resulted in a loss of the interference fit^[3] between the wheel and the axle, which allowed the wheel to move inwards along the axle. The point of derailment was at 360.829 km. The derailment of the R4 wheel caused the bogie to rotate and derail the other three wheels. The other paired wheel on the front wheelset (L4), rotated to the extent that it started rubbing against the electronically controlled pneumatic (ECP) ^[4] train line brake cable. The abrasion of the cable caused the three locomotives to lose power and return the locomotives to idle.

The derailed bogie continued causing damage to over 590 metres of track including 963 sleepers. Pieces of the wheel detached and were later found on the track (Figure 2).

Figure 2: Wheel pieces from failed wheel found in ballast

Source: ATSB

One significant piece of the failed wheel was not found. This piece was likely the first piece to break away and the reason it was not found may be that it occurred sometime in the days leading up to the derailment. It is possible this missing piece might have been the cause of the increase in impact readings in the lead-up to the derailment.

Figure 3: Damaged Electronically Controlled Pneumatic train line brake cable

During the derailment the L4 wheel rubbed against, and damaged, the ECP cable causing the train to come to a stop.

Source: ARTC

Post occurrence

The train came to a stand at 0618 with the front of the train standing at 359.878 km^[5]. At 0622, the train crew contacted Australian Rail Track Corporation (ARTC) Network Control Centre North (NCCN) to inform them there was a problem with the ECP braking system. Shortly afterwards the train crew contacted the Downer Rail helpdesk^[6] for advice and then contacted the Pacific National operations superintendent to discuss their next action. The operations superintendent directed they secure the train by applying all of the wagon handbrakes.

The driver remained in the cab of the leading locomotive while the second person climbed down from the cab, walked alongside the train and applied the handbrakes. Once this was completed the crew were advised by Downer Rail to verify all jumper couplings were connected. The second person completed this task and on the return from the rear of the train he noticed all wheels of a bogie had derailed (Figure 4 and 5). He informed the driver of the derailment using his handheld radio. At 0810, the driver informed the operations superintendent that the train had derailed.

Figure 4: Derailed bogie viewed from Down side of track

This shows the derailed bogie and the failed wheel that movedoff the wheel seat towards the centre of the axle.

Source: ARTC

Figure 5: Derailed bogie viewed from Up side of track

This shows the derailed bogie at the point the train came to a stand.

Source: ARTC

Following the notification of the derailment, the Pacific National operations superintendent notified the Pacific National operations supervisor at Werris Creek and requested that he proceed to the derailment site to conduct drug and alcohol testing of the train crew. He then notified Downer Rail’s maintenance depot manager and requested that a representative from Downer also attend the derailment site for recovery purposes.

At 0829, an ARTC Network Controller called the driver to get an update on the ECP fault. He was advised that the train had derailed.

At 0915, a Pacific National supervisor, a Pacific National safety and environmental specialist and a Downer Rail production leader arrived on site to coordinate the recovery operations. The ARTC issued a condition affecting the network (CAN) notice at 0928, and a track occupancy authority (TOA) to provide track safety protection at 0941.

During the site inspection, pieces of the failed wheel were found in the ballast. One piece was found 7 m forward of the point of derailment on the Down side of the track. Another piece from the wheel, brake blocks and brake block keys were found inside the four foot. An unsuccessful search was conducted for another large piece from the failed wheel.

The train crew were breath tested at 1128 with a negative result. This was over five hours after the incident. At 1140 the train crew were relieved of their duties.

Because of the derailment the sleepers that sustained damage were replaced and on 31 August 2015, the TOA was fulfilled, ending the track safety protection.

__________

1. The 24 hour clock is used in this report. Local time was Australian Eastern Standard Time (AEST).
2. Bank locomotive – a locomotive(s) provided at the rear of a train to assist it up a steep grade (bank).
3. Interference fit - The locking of two components together by friction. In relation to the wheelset, the hole in the wheel is made slightly smaller than the axle diameter. When the wheel is pressed onto the axle high forces lock the components together.
4. ECP – Electronically controlled pneumatic braking system is an electrically controlled system that applies or releases the service brake on each wagon simultaneously at the driver’s command. The system connects from the locomotives to each wagon both electrically and pneumatically. Also incorporated in the system is a shadowing feature that automatically applies the brakes should the electrical connection between the wagons be broken or the air supply lost. The ECP cable between the cars is known as an inter car connector or a jumper.
5. NSW track kilometrage is measured from Central Station, Sydney.
6. Downer Rail is Pacific National’s maintenance contractor and technical helpdesk provider to PN operations.

Context

Incident location

The incident occurred at 360.829 km on the Main North line at Pangela between Ardglen and Pages River (Figure 6). The train was travelling towards Port Waratah.

Figure 6: Location of incident at Pangela

This map shows the incident location and the path of MB520 (shown in red).

Source: Geoscience Australia

Train information

MB520, was a loaded coal service operating from the Maules Creek coal mine to Port Waratah. The train consisted of three locomotives TT 119, 9307 and TT 1 and 82 fully loaded coal wagons (Figure 7). The train was 1326 m long and had a trailing load of 9840 tonnes.

The wagons in the consist were a hopper type wagon with a 30 tonne axle load. Eighty wagons were NHIH-type wagons^[7] and two were RHDH-type wagons. The wagon involved in the derailment was NHIH97081. Programmed maintenance was last carried out on the wagons on 29 June 2015, this is when the wagons would last have undergone a static inspection.

The leading ‘A’ end bogie that derailed was a NECA71 three piece bogie, last overhauled by Bradken, a maintenance contractor, in October 2013.

The wheelset (1G6S981356) was reprofiled (a skim taken off the tread face of each wheel) and installed under the wagon on 18 September 2014; it had since travelled 122,300 km. It was estimated to have travelled over 2 million kilometres since manufacture.

The failed wheel (R4) was manufactured by Comsteel in 1998 as part of the wheelset supplied to Pacific National. The wheel discs were the original discs as fitted to the axle. The serial number of failed wheel was not able to be determined due to derailment damage, but the paired wheel (L4) had a serial number 98 9891 CSC S6479. The maintenance records show that the other wheelset on the same bogie was removed on 23 October 2014 when a bearing replacement was made.

A data logger analysis was conducted on each of the train’s locomotives. The investigation concluded that the management of the train from Maules Creek did not contribute to the derailment.

Figure 7: Loaded coal wagons

This photo shows a number of loaded NHIH-type wagons in the consist of MB520.

Source: ARTC

Train crew

The train was crewed by a driver and a second person based at Port Waratah. The train crew were appropriately qualified and held the required route qualifications.

Track information

The section of track where the derailment occurred was a single, bi-directional, standard gauge railway line. Signals were controlled by ARTC Network Control Centre North at Broadmeadow. The track configuration was ARTC Class 1XC standard heavy haul track with 60kg/m rail directly fastened to concrete sleepers with resilient Pandrol type clips on a ballast formation and capable of 30 tonne axle load operations.

The section of track where the leading bogie of vehicle NHIH 97081T derailed was a steep 1 in 38 falling grade with a relatively tight 240 m radius. The posted track speed was 55 km/h.

The track was controlled and maintained by ARTC. ARTC controls the interstate rail network plus the NSW Hunter Valley rail network as part of a 60-year lease with the NSW State government from September 2004.

The Main North line starts from Sydney extends north towards the Queensland border. It once was the main line to Queensland but is now closed beyond Armidale. The track carries both freight and passenger trains. Coal trains dominate, especially between Port Waratah and the coalfields of the Hunter Valley, Gunnedah and the Narrabri Basin.

According to a report commissioned by Pacific National, the track infrastructure was in a good serviceable condition prior to the derailment and ARTC had maintained the track according to the relevant standards.^[8] The investigation found that track condition did not contribute to the derailment.

Related occurrences

In Australia, the number of derailments caused by wheel failure is difficult to determine due to the lack of coordinated data collection. An examination of NSW Independent Rail Safety Regulator’s annual rail safety industry reports from 2007 to 2012 did not mention any incidence of wheel failure in NSW over this period.

On 28 May 2011, there was a failure of a locomotive wheel on an intermodal freight train at Fisher in South Australia. The ATSB investigation found that a fatigue crack had initiated on the wheel rim and then radiated towards the flange and tread regions before the wheel completely failed. The rate of growth of the fatigue crack was influenced by high in-service mechanical loading of the wheel. The initiating mechanism was different from the one in this investigation.

Pacific National wheel incidents

Significantly, there have been seven reports of fractures detected in wheels, within a 3-year period, on Pacific National coal wagons in NSW (Figure 8). Three occurred over a 27-month period before this incident and three within a two-month period afterwards. None of the other incidents resulted in derailment. Five of the defects were found during maintenance, some detected inadvertently when the maintenance team were carrying out other work.

Figure 8: Pacific National wheel incidents

This table summarises the recent spate of Pacific National wheel fractures

Source: Pacific National

The first in this series of incidents occurred at Metford. According to Pacific National, this incident was the first identified wheel failure since the installation of wheel condition monitoring in 1998.^[9] On 31 May 2013, a high wheel impact load reading of 465kN was recorded by the ARTC Wheel Impact Load Detector (WILD) wayside equipment at Metford.^[10] The train was subsequently stopped at Greta where the train crew inspected it. A partial wheel failure of the wheel tread was identified on a wheel on the 16th wagon. The WILD readings for this wheel had escalated during the weeks leading up to the final reading. The readings over the preceding weeks were: 200kN on 3 May, 236kN on 26 May, 246kN on 28 May, 317kN on 30 May, and 338kN again on 30 May. Interestingly, on 30 May, a senior Pacific National employee reported a possible skidded wheel or spalling defect due to pass-by noise at Greta. A roll-by examination was conducted at low speed at Maitland but no defect was detected. A further roll-by examination at the Newcastle Hunter Bulk terminal did not detect the defect. It was not until 1410 the following day, 31 May 2013, that the high WILD reading caused the train controller to contact the train crew and advise them to conduct an immediate technical examination.

The wheelset was three weeks short of its final scheduled maintenance, when it was to be removed from service. After metallurgical analysis, an investigation found that the failure mechanism was the result of a transverse thermal crack at the edge of the rim front face and tread. This failure is typically caused by excessive localised thermal load into the wheel tread and is generally associated with braking issues on the wagon. This was in combination with the wheel rim having a diminished thickness due to the wheel approaching its condemning diameter. Higher temperatures will occur during braking when the wheel is worn than when it is new. There will also be a tendency to sustain these higher temperatures due to the reduced capacity of the wheel rim to dissipate this heat.

The second incident occurred on 25 August 2013 during non-scheduled maintenance when maintenance staff, while grinding arrisses, incidentally detected a significant wheel fracture on a coal wagon. The defect was identified as a shattered rim where fatigue had initiated at a sub-surface position and then propagated through the wheel’s outer rim (see Appendix A for wheel terms). The cause of the fatigue defect was not identified.

Two days prior, on 23 August 2013, the WILD reading changed from a normal reading of 110 kN to 166 kN. On 25 August it increased to 207kN, well below the 250 kN limit where any preventative action commences. The Pacific National report into the incident made a number of observations about this incident and the previous May incident. It said that while the failure mechanism was different they had a number of similarities, both:

• were in the fully worn, minimum rim thickness condition
• had fatigue cracking initiating from a sub-surface condition
• were fitted to NHRH wagons, operating in the same environment
• exhibited rim edge angularity
• exhibited thermal cracking.^[11]

It stated that they had instituted a program to monitor WILD readings on wheels with a low rim thickness and remove any that see an increase in WILD readings. It was found that 6.5% of wheelsets have a rim thickness of 25 mm or less when returned to the maintainer. It recommended an increase in the minimum rim thickness on 30 t axle load wagons to 28 mm on wheel turning. It stated that a minimum rim thickness of 28 mm will ensure that the stresses in the wheel are lower than that experienced in the two wheel failures (31 May and 25 August 2013). There is no evidence that any of the recommended measures were put in place by Pacific National prior to the derailment on 28 August 2015.

On 4 November 2014, a third wheel fracture was detected during scheduled maintenance, at the maintenance facility at Greta, here a crack was found on the tread and the front inner rim of the wheel. Subsequently a metallurgical examination by Comsteel found numerous cracks at the tread/front face location around the entire circumference of the wheel. The metallurgical report concluded that the thermal cracking^[12] may have been initiated by a misaligned brake block causing a high thermal load. The report stated, ‘The rim thickness of the wheel was almost at condemning level. This very thin rim section leads to lower rim rigidity and, hence, higher propensity to unusual thermal distortion and would be a significant contributing factor into thermal crack formation and propagation.’^[13]

The fourth incident at Pangela on 28 August 2015, which resulted in a derailment, is the subject of this report.

The fifth incident detected on 25 September 2015 during maintenance found two large cracks and numerous smaller cracks on the circumference of the wheel. A metallurgical analysis of this wheel determined the cracks were typical of thermal cracking likely caused by excessive braking or a brake block overhanging the rim edge.

The sixth incident was detected on 6 October 2015, again during unit train maintenance. Eight large cracks and numerous smaller cracks were found on the circumference of the wheel. No metallurgical analysis was conducted on this wheel.

The seventh incident detected on 7 October 2015 was from the same wagon as the previous incident but from a different bogie. A series of rim edge thermal cracks were found during a targeted maintenance inspection.

The actions taken by the rail operator and the rail regulator as a result of the first three incidents are discussed in the safety analysis section of this report.

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7. NHIH wagons - The NHIH were the replacement wagons for the NHPH and NHQH wagons with the bogies refitted to the new NHIH wagons.
8. Robinson Rail, ‘Derailment of Coal Train ID MB520’ Report on condition of track infrastructure, 28 August 2015.
9. Pacific National set the minimum rim thickness at 22mm for freight vehicles over 25 tonne axle load. (For rim thickness measurement see Appendix A).
10. Pacific National Coal Asset Management, ‘Technical Report Class 5 fractured wheel NHRH50361 31 May 2013’. August 2013. p.5.
11. Wheel Impact Load Detector (WILD) - Measures the force of impact on the track caused by each wheel in the train consist. This can provide early detection of wheel defects such as skids and wheel out-of-round. The WILD was originally installed to detect wheel defects that introduced damaging impact loads to the track.
12. Pacific National Asset & Infrastructure services (2014) Incident 73495 Shattered wheel report NHRH 50264J 25 August 2013. p.13.
13. Thermal cracks are the result of alternate heating and cooling of the wheel tread and rim area, and originate from metallurgical changes in the wheel material. Thermal cracks are the most severe form of wheel defect. (NSW Asset Standards Authority’. Wheel defect manual’ May 2013. p.8.)
14. Comsteel, ‘Evaluation of Pacific National W69 NHRH Coal wagon wheel cracking in the wheel rim’. April 2015. p.13.

Safety analysis

The investigation determined that the derailment at Pangela was caused by a wheel failure. The R4 wheel fractured from the rim through to the boss causing a loss of interference fit and resulting in the wheel becoming dislodged from its seat and moving inward towards the centre of the axle. The fracture initiated as a transverse thermal crack in the wheel tread and, due to cyclic stressors, progressed by fatigue crack propagation to eventual failure.

This section examines the metallurgical aspects of the wheel and its fracture. It also explores wheel condition management including wayside monitoring, and risk management by the rail operator.

Metallurgical aspects of the wheel failure

All parts of the derailed bogie, wheelset, and the available fractured sections of the wheel recovered from site were examined and photographed by investigators and technical analysts from the ATSB at a Pacific National workshop at Port Waratah. Testing requirements were discussed with specialists from the ATSB, Comsteel, the Office of National Rail Safety Regulation (ONRSR) and Pacific National. Pacific National engaged the technical services of Comsteel to conduct the metallurgical analysis of the failed wheel. The scope and steps for the metallurgical investigation was agreed upon by these specialists before the wheelset and wheel pieces was taken to the Comsteel testing facility in Newcastle. The final metallurgical report^[14] was examined by technical analysts from the ATSB who accepted the methodology and conclusions.

The metallurgical report concluded that multiple thermal cracks had initiated in the wheel rim. A magnetic particle inspection revealed six thermal cracks at a number of locations around the circumference of the wheel tread. It also found two cracks in the wheel rim. One of the thermal cracks progressed by fatigue until it extended from the rim to the boss of the wheel and was responsible for the loss of the interference fit between the wheel and the axle, which allowed the wheel to move inwards along the axle and initiate the derailment. The other crack extended 90 mm from the rim into the rim.

The report stated: ‘It is highly suggestive that the fracture was initiated by a transverse thermal crack in the wheel tread. This type of transverse thermal cracking is typically cause by excessive localised thermal load into a vulnerable region of the wheel tread and is generally associated with abnormal braking load.’

• The evidence from the metallurgical report also found:
• the failed wheel complied with industry specification requirements
• it exhibited a high level of steel cleanliness and no material abnormalities
• rolling contact fatigue indications were detected toward the flange side of the tread
• the inner rim exhibited a rough, blistered and corroded surface
• rim profiles from both wheels showed no significant deviation from original profile
• residual stress measurement on both wheels was not possible.^[15]

The paired wheel on the wheelset was also examined but no thermal cracks were detected on its wheel tread. This suggested that, at some time prior to the crack formation, there was uneven distribution of braking energy between the two wheels on the wheelset. The appearance of the rough/ blistered /corroded surface on the inner rim of the failed wheel supports the likelihood that there was thermal loading on the wheel rim (Figure 9-1). There were indications on the paired wheel of a white etching layer (Figure 9-2), this is usually indicative of a heat-affected area possibly also caused by a braking event. It appears further away from the rim edge than those classified as near rim edge and has no crack indications. No heat-affected areas of this type were found on the failed wheel, but this evidence would likely have been removed due to the gouging of the wheel after the derailment when it was dragging in the four foot.

Figure 9: Heat indications on wheels

Image 1 shows the surface condition that may indicate overheating of the wheel rim of R4. Image 2 shows an area of white etching layer on the paired wheel L4, which was indicative of a heat affected area.

Source: Comsteel

There was no evidence of any problem with the brake mechanism or brake blocks on bogie NECA71. In addition, there was no record of wayside alarms for high wheel temperature for the wagon. This increases the likelihood that any thermal loading event would have occurred under service brake conditions.

Evidence of overhanging brake blocks was found on two other incidents, 6 October 2015 and 7 October 2015. The incident on 4 November 2014 and the subsequent Pacific National report discussed reducing the risk of brake block overhang by modification of the bogies by reducing the lateral float of the brake beam. There is no evidence that this was addressed prior to the derailment on 28 August 2015 Pacific National have recognised that this is an area of concern and are now trialling fitting modified brake beam liners to self-steering bogies on coal wagons.

The metallurgical report found that the failed wheel was approaching the end of its service life with a rim section 25 mm thick. This thin rim section leads to lower rim rigidity and, hence, higher propensity to unusual thermal distortion and would be a significant contributing factor into the thermal crack formation and propagation. Examples of thermal cracks identified by Comsteel during the metallurgical analysis are shown in Figure 10.

The high wheel loading (30 tonne axle loads) and the cyclic thermal braking events are also likely to have influenced the propensity for crack propagation once the thermal crack was initiated. Research into overheating of wheels found: ‘The loss of compressive residual stress and the development of tensile residual stress in the wheel rim due to overheating can contribute to fatigue failure of the wheel. A reduction in rim thickness due to wear and re-profiling also alters the residual stress distribution, and may increase the risk of wheel failure.’^[16]

The ONRSR Safety Bulletin, (see Appendix D) identifies many other factors which contribute to these defects: ‘developments such as electronically controlled pneumatic braking (which can increase maintenance intervention periods), steering bogies (which can reduce wheel to rail contact area), micro-alloyed wheels (which are longer lasting wheels), and solid drawbar assemblies (which can increase maintenance intervention periods).’^[17]

Figure 10: Thermal cracks identified during metallurgical analysis

Image 1 shows the location of the thermal cracks in relation to the fracture. Image 2 identifies thermal cracks located on the front face of the wheel tread.

Source: Comsteel

Wheel condition management

Pacific National has in place a number of measures to monitor and manage the condition of its wheels and rollingstock. The primary method used to monitor and manage wheel condition is dependent on inspections conducted by Pacific National employees including train crew, maintenance staff and terminal operators.

A number of visual and audible examinations are regularly carried out. These include but are not limited to the following:

Terminal departure and arrival examinations. These are conducted at a low speed, usually about 10km/h. A terminal operator stands near the track and looks and listens for any abnormalities as the train passes.

Roll-by examinations. Conducted by train crew on one train as another train passes by. One train might be stationary or both might be operating at track speed. After the roll-by inspection radio communication occurs between crews to verify that no defect was present. Roll-by examinations also carried out by staff standing trackside at unloading points.

Full examination (FX). These full inspections are conducted while the train is stationary at a maintenance facility or terminal by examining staff at regular intervals (Coal trains at 28-day intervals). Note that the previous inspection for MB520 was on 29 June 2015, 60 days before the derailment.

Unit Train Maintenance (UTM). A more structured static full examination is conducted during UTM at a maintenance facility every 128 days.

Identifying a wheel defect, especially in the early stages, can be difficult. There are many factors that reduce the likelihood of the detection of a wheel defect, these include:

• speed of the train as it passes by
• environmental conditions such as lighting, noise levels and weather
• defects obscured by other components
• position of the wheel
• experience of the observer
• fatigue and motivation level
• time pressure to complete task.

Pacific National have a dedicated wheel condition monitoring team with a number of analysts based in Adelaide, Melbourne and Port Waratah. These analysts collect and analyse wheel data to assist them managing the Pacific National fleet. Some of the data collected by the wheel condition monitoring team includes wheel rim thickness, wheel age, and wheel impact loading. They also monitor wheel profile which is available from one location. Most of the condition monitoring is in relation to wheel wear and organising the examination events for the lifecycle of the wheel. It currently does not, and is not able to, identify wheel defects while the wheel is in service. The use of WILD data, which is explained more fully later, is an indirect way of detecting wheel defects.

The condition monitoring team based at Port Waratah operates during office hours on a 5-day roster. On this basis not all wheel defects will be attended to immediately. They receive electronic data and email alerts from ARTC wayside monitors and their own wheel profiler at Greta. Based mainly on past experience, the condition monitoring team develop strategies to minimise the likelihood of wheel defects and maximise the life of the wheel.

Since 2012, Pacific National has used a wheel profile monitor at the Greta maintenance facility in the Hunter Valley. Using laser and optical devices, it measures the wheel profile, wheel flange thickness and other parameters such as back-to-back measurements as the train passes at low speed. The profile parameters are used to predict wheelset optimum removal time and identify poorly wearing wheelsets.

Wheel profile data for the failed wheelset, collected before the derailment, indicated that it was within allowable wear limits, later confirmed by the metallurgical report. The back-to-back measurement for this wheelset was not recorded for the previous two passes prior to the derailment. It was initially postulated that this was caused by the wheel moving on the axle, giving early indication of wheel failure. An examination of wheel profile records found that a null data reading was a common occurrence for back-to-back measurements. Inaccurate measurements result from variation in the wheel chamfer profile. It is more likely that the missing data is a characteristic of the wheel profiler and not related to the progression of the wheel failure. Improvement in the reliability of this device would assist Pacific National in their management of wheel condition.

Wayside monitoring

There is currently no wayside detection system that can detect cracks on in service trains except at workshop maintenance when post wheel turn non-destructive testing is carried out to check a defect has been removed. Following wheel manufacture, once non-destructive testing is completed, the rollingstock operator primarily relies on visual inspections by train crew, terminal operators, and wagon maintenance staff to detect wheel fracture. The WILD will provide information if the defect is of the type that will cause an impact to be recorded. Typically this will be something like a chip or gouge in the wheel flange, out of round wheels, skidded wheels, and cracks where a portion of the wheel has fallen away. Early stage cracks and thin deep cracks are not detected as minimal impact forces are generated.

The network access provider, the Australian Rail Track Corporation (ARTC), operate and maintain the wayside monitoring systems in the Hunter Valley where this incident occurred. There are different types of wayside devices including detectors for hot bearings, wheel impact loads, acoustic wheel monitoring, and weighbridges. These monitoring systems can be split into two generic types, reactive and predictive. A reactive approach requires an immediate action after a serious condition develops or equipment failure occurs, whereas a predictive approach identifies the requirement for future action before a serious condition develops. Reactive condition monitoring, such as hot bearing detectors, are usually used as the last line of defence to protect significant or critical railway infrastructure assets.

For a more detailed description of their function, see Appendix B.

These trackside systems are primarily used by ARTC to prevent damage to the track infrastructure. They detect a variety of rollingstock and track faults and are positioned at strategic locations in the network (Figure 11).

Figure 11: Wayside monitoring equipment system map

Source: ARTC – redrawn by ATSB

The system comprises a variety of wayside devices, which communicate readings to an ARTC data recording and alert system. Each train and wagon is identified using Automatic Equipment Identification (AEI), each wheelset is also counted. The wayside detection system records data, and at set levels, notifications are sent to ARTC and at times to the rollingstock operator. The pathway for a WILD wayside system alert to ARTC and Pacific National is included at Appendix C.

The failed wheel (R4) was initially identified by the WILD at Metford on 28 July 2015. The WILD then recorded passes by the wheelset until the day before the derailment, with a peak of 326 kN recorded on 26 August 2015 (Figure 12). It is only when the impact level reaches 400 kN that ARTC procedures require more immediate action.^[18] At this impact level, i.e., 400kN, ARTC train control contact the train crew, and request they bring the train to a stop to inspect the nominated wheel.

Figure 12: Wheel Impact Load Detector readings

WILD readings from the failed wheel (R4) prior to the derailment and Pacific National’s actions.

Source: ATSB

A work order for the removal of the wheelset was created on 26 August 2015, two days before the derailment, in accordance with the Pacific National decision matrix table.^[19] The table specifies the action when the WILD reading reaches a certain threshold. This alert was triggered once the second reading in the 300-350 kN range was reached in the month. The alert was sent to the Pacific National wheel condition monitoring team, where a work order was raised to remove the wheelset by 20 September 2015. Pacific National classified the earlier impact levels, from 28 July 2015, as requiring monitoring.

Pacific National use the ARTC wayside monitoring system for two main areas (see Appendix B for explanation of terms):

• Wheelset condition monitoring using a Wheel Impact Load Detector (WILD) and Bearing Acoustic Monitoring (RailBAM)
• Bogie condition monitoring using Truck Bogie Optical Geometry Inspection (TBOGI) and Rail Squeal Acoustic Detection (RailSQAD).

Pacific National has limited access to the WILD data and impose lower impact level thresholds than ARTC. The purpose of these thresholds is to detect bearing failures that are associated with wheel impacts. Pacific National acknowledge that the WILD wayside data is an indirect way of detecting wheel fracture, is a lagging indicator, and not what the system was principally designed for.

Risk management

As required by national rail safety legislation, Pacific National, as an accredited rail operator, has in place a Safety Management System. This system includes a risk register which identifies major operational risks and the control measures which the operator has in place to prevent and manage the risk.

As part of managing risk, Pacific National have developed technical standards that apply to their rollingstock. These standards are consistent with the Rail Industry Safety and Standards Board codes of practice. As part of the Safety Management System process, these standards are monitored and reviewed.

Pacific National, in their Operational Risk Register^[20], identified the risk of derailment caused by defective wheels, where the defect was caused by a vertical split or shattered (fractured) rim. Using estimated consequence and likelihood levels for a defective wheel and with the above control measures in place, Pacific National calculated the residual risk level in the high category.

The control measures identified for the identified risk were:

• Wagon maintenance manual WMM 09-11
• Generic procedures GRP6 16 and GRP6 23
• Procedures NSWCO-032 and 033
• Ultrasonic testing regime on 100 tonne axles
• Physical/ visual inspection regime of axles for strike marks by maintainers during UTM
• Network Owner Wayside Monitoring Equipment.

The controls measures listed, with the exception of the wagon maintenance manual, are not specifically aimed at controlling wheel failure. The procedures and ultrasonic testing are for axles not wheels. The wayside monitoring systems are currently not developed to detect early stage wheel fractures. The wagon maintenance manual is limited to describing the typical faults found by visual inspections and the action to take when the defect is detected. These risk management strategies developed by Pacific National are not likely to increase the probability of detection of wheel failure since the first identified wheel incident.

As a result of the first two identified Pacific National wheel incidents in 31 May 2013 and 25 August 2013, ONRSR published a Safety Bulletin in June 2014. It was titled: “An emerging issue: ‘shattered rim’ wheel defects”, and is included at Appendix D.

This bulletin stated that, while not so common in Australia, shattered rims are one of the most significant causes of rail wheel failures in North America. It said that as rail wheels age, the effects of fatigue can cause a defect to develop. The safety bulletin reminded operators to question current maintenance and wagon inspections and enhance wagon maintenance for those wheelsets which are approaching condemning diameter.

Two control measures were suggested for operators to include:

• non-destructive testing during manufacturing phase, and
• trackside detection and monitoring devices.

It concluded that Australian rail operators, depending on their operating environments, may need to review and revise current risk registers in order to manage to a ‘so far as is reasonably practicable’ level the hazards associated with a wheel failure due to a shattered rim.’

It is likely the low rim thickness was a contributory factor in the previous Pacific National wheel cracks. Thin rim sections were found in the other six reports of fractures detected in wheels (Figure 8). The rim section thicknesses ranged between 22 – 26 mm. The maximum rim thickness in the fleet was 57 mm with the average being 50 mm.

After the first incident on 31 May 2013, Pacific National commissioned a metallurgical investigation and completed an internal investigation^[21]. Many aspects of wheel monitoring and procedures were examined; one aspect was the minimum wheel rim thickness. Pacific National operated wheelsets to a 22 mm minimum wheel rim thickness, which is consistent with RISSB code of practice for wheel defects. The Pacific National report made the following observations:

if a 22 mm rim thickness is determined to be a satisfactory minimum rim thickness, the current levels for wheel impact alerts may not be appropriate for 30 tonne axle load wagons, particularly those fitted to self-steering bogies.

the Association of American Railroads (AAR) identifies wheel configuration at low rim thickness being sensitive to large thermal stresses.

Pacific National should undertake a review of wheel stresses for the current wheel design, with particular focus on low rim thickness.

It is unknown if a review of wheel stresses was undertaken by Pacific National following this incident. There was no change to their practice of using wheels with a rim thickness approaching the condemning limit until after the derailment.

As can be seen from Figure 8, most of the defective wheels were running with thin rim thickness. This was because they were not targeted for removal. The age of the wheels ranged from 13 -19 years since manufacture. Although, like the failed wheel from this derailment, and other Pacific National failed wheels since 2013, the wheels were within accepted standards for wheel design, material composition, inclusions, and wear limits.

The change in the Pacific National wheelset rim thickness in the 30 tonne axle load coal fleet from just prior to the derailment in September 2015 to February 2016 is shown in Figure 13. The lower range of rim thickness from 20 mm to 30 mm was selected to be shown as it is the area of most concern, the upper range from 31 mm to 57 mm is not shown. The graph shows the progress of the removal of the bottom range of wheel rim thickness.

Figure 13: Wheelset rim thickness 30 tonne axle load coal fleet

Source: ATSB table from Pacific National supplied data

Pacific National acknowledge that increasing the minimum rim thickness would assist with reducing stresses in the wheel and may act to prevent further failures. Pacific National did not review the application of this value until after the derailment. Pacific National advised that they had implemented various strategies to reduce the incidence of wheel failure. These strategies include:

• Increase the from-workshop outbound wheel turn size upon re-profiling turn from 25 to 28 mm
• Actively remove of wheels with low rim thickness (under 25 mm).

Other proposed actions include:

• Establish a process to identify thin rims and wheel impacts and remove from service wheels considered to be at greater risk of fracture
• Fit modified brake beam liners to bogies on coal hopper wagons to reduce the incidence of overhanging brake blocks and the subsequent formation of thermal cracks
• Conduct a fleet wide inspection of wheels for cracked rims.

__________

14. Comsteel. ‘Customer Quality Report No. 83582 Examination of Pacific National NHIH97081, Wheel Fracture Wheel set 1G6S981356’ December 2015. p.16.
15. Rail wheels are manufactured with a compressive hoop stress to provide additional fracture resistance. Once the wheel failed this measurement cannot be made.
16. Mutton and Laczko. Metallurgical and NDT aspects in the management overheated railway wheels. MATe05 paper. 2006.
17. Office of National Rail Safety Regulator (2014). An emerging issue ‘shattered rim’ wheel defects. Safety Bulletin No. 3 June 2014, p.2.
18. ARTC Wheel Impact Load Detection (WILD) Alarm Specifications 12 March 2014, p.4.
19. Pacific National. Management of Wayside Condition Monitoring Systems, Wagon Maintenance Manual. 01-12_02. 4 November 2009.
20. Pacific National. ‘Operational Risk Register ORR NSW-Vic’. 16 June 2015.
21. Pacific National. ‘System Safety Accident Investigation into Failure of Wheel Disc No.41574 Class 5 Wheel Fracture Fitted to Wagon NHRH50361M IRS No. 70337 at Greta Date of Incident Friday, 31st May 2013’. 26 March 2014. p.6.

Findings

From the evidence available, the following findings are made with respect to the derailment of freight train MB520 that occurred at Pangela, New South Wales on 28 August 2015. These findings should not be read as apportioning blame or liability to any particular organisation or individual.

Safety issues, or system problems, are highlighted in bold to emphasise their importance. A safety issue is an event or condition that increases safety risk and (a) can reasonably be regarded as having the potential to adversely affect the safety of future operations, and (b) is a characteristic of an organisation or a system, rather than a characteristic of a specific individual, or characteristic of an operating environment at a specific point in time..

Contributing factors

• The derailment occurred due to a wheel failure on the right hand wheel (R4) fitted to the leading axle of the leading bogie of vehicle NHIH97081. This led to the wheel moving off the wheel seat towards the centre of the axle. The bogie then rotated causing the other wheels on the bogie to derail.
• The wheel failed due to the initiation and propagation of a transverse thermal crack in the wheel tread.
• The wheel inspection processes and systems were not effective in detecting surface damage or cracks on the R4 wheel on wagon NHIH97081 prior to the wheel failure. [Safety Issue]

Despite a number of incidents, Pacific National did not take adequate action, before the derailment, to reduce the risk of wheel defects, especially in light of previously identified contributors such as low rim thickness. [Safety Issue]

Other findings

• The rollingstock operator used the data from Wheel Impact Load Detectors as an indirect method to detect wheel surface damage and cracks. However, despite increasing impact level readings during the previous month, no immediate action was taken to inspect the R4 wheel before it eventually failed.
• Metallurgical tests of the failed wheel R4 and the paired wheel L4 found they complied with specification requirements.

Safety issues and actions

Depending on the level of risk of the safety issue, the extent of corrective action taken by the relevant organisation, or the desirability of directing a broad safety message to the rail industry, the ATSB may issue safety recommendations or safety advisory notices as part of the final report.

Wheel inspection processes

The wheel inspection processes and systems were not effective in detecting surface damage or cracks on the R4 wheel on wagon NHIH97081 prior to the wheel failure.

ATSB Safety Issue: RO-2015-015 SI-01

ATSB Safety Recommendation: RO-2015-015-SR-012

Low rim thickness

Despite a number of incidents, Pacific National did not take adequate action, before the derailment, to reduce the risk of wheel defects, especially in light of previously identified contributors such as low rim thickness.

ATSB Safety Issue: RO-2015-015 SI-02

Sources and submissions

Sources of information

The sources of information during the investigation included:

• Australian Rail Track Corporation
• Office of the National Rail Safety Regulator
• Pacific National

References

Asset Standards Authority NSW (2013). Wheel defect manual. May 2013. p.8.

Australian Rail Track Corporation (2014) Wheel Impact Load Detection (WILD) Alarm Specifications, Version 2.0, 12 March 2014, p.4.

Comsteel (2015) Evaluation of Pacific National W69 NHRH Coal wagon wheel cracking in the wheel rim. p.13.

Comsteel (2015) Customer Quality Report No. 83582 Examination of Pacific National NHIH97081, Wheel Fracture Wheel set 1G6S981356. p.16.

Liu. X, Saat. M.R, Barkan. C.P.L. (2012) Analysis of Causes of Major Train Derailment and Their Effect on Accident Rates. US Department of Transportation Region V Regional University Transportation Center Final Report.

Mutton and Laczko. (2006) Metallurgical and NDT aspects in the management overheated railway wheels. MATe05 paper.

Office of National Rail Safety Regulator (2014). An emerging issue ‘shattered rim’ wheel defects. Safety Bulletin No. 3 June 2014.

Pacific National (2009). Management of Wayside Condition Monitoring Systems, Wagon Maintenance Manual. 01-12_02.

Pacific National Coal Asset Management (2013) Technical Report Class 5 fractured wheel NHRH50361 31 May 2013. p.5.

Pacific National Asset & Infrastructure services (2014) Incident 73495 Shattered wheel report NHRH 50264J 25 August 2013. p.13.

Pacific National (2015) Operational Risk Register ORR NSW-Vic.

Pacific National (2014) System Safety Accident Investigation into Failure of Wheel Disc No.41574 Class 5 Wheel Fracture Fitted to Wagon NHRH50361M IRS No. 70337 at Greta, date of Incident Friday, 31st May 2013. p.6.

Rail Industry Safety and Standards Board (2010) Glossary of Rail Terminology – Guideline.

Robinson Rail (2015) Derailment of Coal Train ID MB520 Report on condition of track infrastructure.

U.S. Department of Transportation Federal Railroad Administration (2014) Broken Rims in Railroad Wheels.

Submissions

Under Part 4, Division 2 (Investigation Reports), Section 26 of the Transport Safety Investigation Act 2003 (the Act), the Australian Transport Safety Bureau (ATSB) may provide a draft report, on a confidential basis, to any person whom the ATSB considers appropriate. Section 26 (1) (a) of the Act allows a person receiving a draft report to make submissions to the ATSB about the draft report. A draft of this report was provided to:

Australian Rail Track Corporation

Office of the National Rail Safety Regulator

Pacific National

Submissions were received from the Australian Rail Track Corporation, the Office of National Safety Regulator, and Pacific National. The submissions were reviewed and where considered appropriate, the text of the report was amended accordingly.

Appendices

Appendix A – Wheel information

Figure 14: Standard terminology for wheels

Figure 15: Measuring the rim thickness

In this example, the rim thickness is 48 mm.

Appendix B – Wayside monitoring systems

The following wayside monitoring systems were not designed to detect wheel failure. Each system has its own focus and method of operation.

Wheel Impact Load Detector (WILD)

Used to measure the effect of wheel impacts on the rail surface under dynamic conditions. This can provide early detection of wheel defects such as skids (wheel flats), and wheel out-of-round. Originally designed to protect track from high energy impacts from wheels. It consists of arrays of accelerometers and train presence switches clamped to the rails. It provides alerts to the network owner and also to rollingstock operators.

Hot box detectors

Hot-box detectors are a reactive method of condition monitoring. They usually detect the infrared signature of bearing components and alarm if the temperature exceeds a predetermined setting.

Consequently, hot-box detection is usually used as a ‘last line of defence’ to protect railway infrastructure assets critical to production processes such as coal and ore carrying railways.

Rail Bearing Acoustic Monitoring (RailBAM)

Bearing Acoustic Monitoring (BAM) is a predictive condition monitoring system that ‘listens’ to the acoustic signature of bearings and can detect faults as they develop. It is the primary method for detecting potential bearing faults on rolling-stock travelling on the interstate main line. Recorded data from each train is stored in a database allowing evaluation, trending and maintenance scheduling of rolling-stock based on predicted bearing condition.

BAM uses sensitive acoustic arrays to record the sounds emanating from wheels and bearings passing through the monitoring site. The recordings are processed for the sound characteristics that are unique to specific types of bearing faults. BAM is best at detecting faults on rolling surfaces such as the inner and outer raceways, and rollers in rolling-stock bearings. BAM can also detect looseness or fretting faults and ‘noisy’ wheels (flanging and wheel flats).

Rail Squeal Acoustic Detection (RailSQAD)

Measures acoustic energy to enable comparison of wheel noise trends over time. It measures the energy in the frequency band where wheel squeal and flanging noise are typically found. Wheel squeal is generated when the wheel tread slips on the rail. Excessive levels can be caused by worn wheel profiles and badly tracking bogies. Flanging noise occurs when the taper of the wheel is insufficient to turn the wheelset around a tight corner. The flange then pushes against the inside edge of the rail gauge face to turn the wheelset. A screeching sound is typical on tight corners but increased noise levels may indicate badly tracking bogies, worn wheel / rail profile or a lubrication malfunction.

Truck Bogie Optical Geometry Inspection (TBOGI)

Optically measure the position and angle of passing wheel sets relative to the rail. There are a number of performance parameters, the two most basic are the tracking position and angle of attack. Measurements for each axle are taken, and when parameters are exceeded, an alert is generated. In this way bogie health is monitored which may reduce wheel set replacement, flange wear, rail wear and identify poorly performing bogies.

Weighbridge sites

High and low speed weighbridge sites weigh trains as they pass. Wheel sensors detect the presence of a train, record the number of axles on the train and measure the speed of each wagon. Strain gauge transducers are mounted in the web of each rail with control equipment to store and process the collected data.

Appendix C – Wheel Impact Load Detector flowchart

Appendix D – ONRSR Safety Bulletin

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through: identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

What happened

On 5 July 2015, the pilot of a Cessna 182 aircraft, registered VH-AHC, conducted a local flight from a private airstrip about 100 km south-west of Bourke, New South Wales. The aircraft took off towards the west. After a flight of about 15 to 20 minutes, the aircraft returned overhead the airstrip. Based on the indicated wind, the pilot elected to conduct an approach to land towards the south.

When on final approach to land, at about 5 ft above ground level, the aircraft sank rapidly. The aircraft landed heavily and the nose wheel detached from the aircraft. The aircraft then bounced into the air, touched down for a second time, and dug into soft ground. The aircraft flipped over and came to rest inverted, resulting in substantial damage (Figure 1). The pilot and two passengers sustained minor injuries.

Pilot comments

The pilot reported that the property had received about 100 mm of rain over a period of 2 weeks, which had stopped about 7 days prior to the incident. Cold weather in the intervening period had prevented the soil from drying. Prior to taking off, the pilot had driven over the runway surface and assessed the surface to be suitable for landing. However, below the runway surface, there was a soft layer of earth. This layer extended about 500 mm down and was not evident during the runway inspection.

The pilot was unsure what caused the aircraft to sink faster than usual. The wind was light and variable. The additional sink and high rate of descent combined with the soft surface led to the aircraft landing gear digging in and flipping the aircraft over.

Figure 1: Accident site of Cessna 182, VH-AHC

Source: Aircraft owner

Safety message

This incident highlights the importance of the identification and management of risks associated with unsealed airfields. Potential hazards such as changes in the runway surface following rain can be hard to detect. Changes in the runway surface can adversely affect the outcome of a hard landing.

The ATSB report regarding a similar incident is available on the ATSB website at AO-2015-038.

Aviation Short Investigations Bulletin - Issue 42

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2015 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

What happened

On 15 August 2015, the student pilot of a Cessna 172 aircraft, registered VH-MJK (MJK) conducted a solo flight from Emkaytee aeroplane landing area (ALA) to Bathurst Island Airport, Northern Territory (Figure 1). There the student pilot completed touch-and-go circuits for about 30 minutes on runway 15.

Figure 1: Image showing Bathurst Island, Darwin and Emkaytee airports

Source: Google earth – annotated by the ATSB

At about 1210 Central Standard Time (CST), a Cessna 404 aircraft, registered VH-ANM (ANM) and operated by Hardy Aviation, departed from Darwin Airport, Northern Territory, on a scheduled flight to Bathurst Island, with a pilot and five passengers on board. The pilot broadcast when inbound and about 15 NM from Bathurst Island Airport on the common traffic advisory frequency (CTAF) of 126.5 MHz, and did not receive any response. At about 1220, the aircraft joined on the downwind leg of the circuit for runway 15 at 1,000 ft above ground level and broadcast joining the circuit. As the aircraft turned onto base, the pilot sighted MJK also on base, at the same height, closer to the runway and estimated it was about 150 m away (Figure 2).

The pilot of ANM immediately manoeuvred the aircraft to the west to increase separation between the two aircraft. After unsuccessfully trying to contact the pilot of MJK on the CTAF, the pilot of ANM briefly selected frequency 126.7 MHz to try to communicate with the pilot of MJK, but again did not receive a response. The pilot of ANM observed MJK conduct a touch-and-go, and kept that aircraft in sight, while overflying and re-joining the circuit on the crosswind leg.

After the touch-and-go, when upwind of the runway at about 500 ft above ground level, the pilot of MJK sighted ANM. ANM was then to the left, above MJK at 1,000 ft, and turning onto the downwind leg. The pilot of MJK then saw that the radio was selected to frequency 126.6 MHz. The pilot checked their flight plan, noted that the correct frequency was 126.5, and immediately changed the radio to that frequency. The pilot of MJK then broadcast a departure call on the CTAF. The pilot of ANM then contacted the pilot of MJK, who advised that the radio had been on the wrong frequency.

Figure 2: Bathurst Island Airport showing approximate aircraft tracks and relative positions

Source: Google earth – annotated by the ATSB

The pilot of ANM continued the approach, and landed at Bathurst Island, and MJK returned to Emkaytee without further incident.

The radar data provided to the ATSB by Darwin air traffic control, indicated the aircraft came within about 100 ft vertically and 0.6 NM at the closest proximity (Figure 3).

Figure 3: Radar display showing relative aircraft positions

Source: Department of Defence – annotated by the ATSB

Safety action

Whether or not the ATSB identifies safety issues in the course of an investigation, relevant organisations may proactively initiate safety action in order to reduce their safety risk. The ATSB has been advised of the following proactive safety action in response to this occurrence.

Operator of VH-ANM

As a result of this occurrence, the operator of VH-ANM advised the ATSB that they have taken following safety action:

Notice to company pilots

The Chief Pilot distributed a notice to all company pilots advising them of the incident. The notice stated that the Tiwi Islands continue to be a hot spot for traffic, and reminded pilots to be ‘doubly aware’ when operating in the area.

Safety message

The pilot of MJK commented that there were three important learnings from this incident:

• crosscheck the selected frequency against the flight planning notes
• ensure the selector reaches the detent when selecting a radio frequency
• listen for the ‘beep-back’ response from the CTAF to verify the correct frequency has been selected.

An aerodrome frequency response unit (AFRU) identifies correct radio frequency selection at non-towered aerodromes. The AFRU automatically responds to a transmission on the CTAF either with a pre-recorded voice message, if no transmission has been received in the previous five minutes, or with a beep-back.

The booklet A pilot’s guide to staying safe in the vicinity of non-controlled aerodromes outlines many of the common problems that occur at non-towered aerodromes, and offers useful strategies to keep yourself and other pilots safe.

Aviation Short Investigations Bulletin Issue 44

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2015 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

On 16 August 2014, an Airbus Helicopters AS350B2 Squirrel, registered ZK-HYO, collided with terrain at Mt Alta in the New Zealand Southern Alps. One of the seven occupants of the helicopter was fatally injured and the aircraft destroyed.

The New Zealand Transport Accident Investigation Commission (TAIC) opened an inquiry into the accident on 16 August 2014 (TAIC investigation AO-2014-005). As part of that investigation TAIC recovered the helicopter’s engine for later technical examination. Subsequently, TAIC arranged for the engine examination to be carried out at the engine manufacturer’s facility in Sydney, New South Wales.

On 21 August 2015, TAIC requested the ATSB to appoint an accredited representative in accordance with Annex 13 to the Convention on International Civil Aviation Aircraft Accident and Incident Investigation. The ATSB appointed an accredited representative that day with the task of providing independent oversight of the TAIC engine examination.

To facilitate this support, the ATSB initiated an external investigation under the provisions of the Transport Safety Investigation Act 2003. The ATSB forwarded its report of the engine examination to TAIC on 29 October 2015. This completed the ATSB’s support of the TAIC investigation.

TAIC is responsible for, and will administer the release of the final investigation report into this accident. Any enquiries regarding the TAIC investigation should, in the first instance, be directed to the:

Deputy Chief Investigator of Accidents
Transport Accident Investigation Commission
Level 16, AXA Center
80 The Terrace
PO Box 10-323, Wellington
New Zealand

Telephone: +64 4 473 3112
Facsimile: +64 4 499 1510
Email: inquiries@taic.org.nz
Web: www.taic.org.nz

____________

The information contained in this web update is released in accordance with section 25 of the Transport Safety Investigation Act 2003.

What happened

On 16 August 2015, the pilot of a Beech A36 aircraft, registered VH-PAK (PAK), conducted a private flight from Pacific Haven to Southport, Queensland. The pilot reported that the aircraft engine ran normally throughout the cruise. At about 0945 Eastern Standard Time, the pilot joined the circuit at Southport Airport, with the intention to land on runway 19.

About 800 m from the runway threshold, at about 150 ft above ground level, the aircraft’s engine stopped. The pilot broadcast a Mayday^[1] and conducted a forced landing (Figure 1). The aircraft collided with trees, resulting in substantial damage and the pilot was not injured (Figure 2).

Figure 1: Southport Airport and accident location

Source: Google earth – annotated by the ATSB

Pilot comments

The pilot provided the following comments:

• The pre-flight inspection was normal.
• Prior to the flight, there were 10 quarts of oil in the engine, with 12 quarts full oil capacity, and the aircraft operable to a minimum of 6 quarts.
• The engine had been running well during the flight.
• The pilot was ferrying the aircraft to Southport for its scheduled annual inspection.
• Due to the relatively short runway, the pilot conducted a shallow approach, to reduce the landing distance required.
• When the engine stopped, as the flaps and landing gear were extended, the aircraft sank quickly.
• The aircraft was fitted with an engine analyser (see Engine data section), which would generate a message to the GPS unit if a fuel tank was low on fuel. The pilot did not receive any fuel warnings.

Figure 2: VH-PAK at accident site

Source: Queensland Police

Engine data

The aircraft’s engine data was reviewed for the flight. Figure 3 shows the recorded exhaust gas temperatures (EGT) and fuel flow for the flight. During the cruise, the fuel/air mixture was leaned to achieve a fairly constant EGT around 1,500 ° Fahrenheit (816 °C). Towards the end of the flight, as the aircraft descended, the EGT decreased. About 2 minutes before the engine stopped, the EGT climbed rapidly. The peak EGT, of about 1,552 °F (844 °C), occurred as the engine stopped (Figure 3). Simultaneously, the fuel flow dropped to zero and the engine rpm increased rapidly. This is indicative of an overly lean fuel/air mixture, and is consistent with fuel starvation.

Figure 3: Engine data

Source: Provided to the ATSB

Post-accident inspection

The engine appeared intact, with all connections also intact. There was no evidence of oil loss from the engine.

During the post-accident inspection, the engineer found that only a few drops of fuel remained in the fuel control unit. The engineer drained the right main fuel tank and airframe fuel filter bowl. Less than 2 L of fuel drained from the right fuel tank, and less than 20 ml from the fuel filter bowl. The right main fuel tank was selected in the cockpit at the time of the accident.

The tip tanks and left main fuel tank were ruptured as a result of the collision, and no fuel remained in them. However, there was no evidence of fuel contamination at the accident site, and only a slight smell of fuel.

Aircraft fuel status

The aircraft had a total fuel capacity of 432 L. It had two main fuel tanks, each capable of holding 140 L of usable fuel. The aircraft was also fitted with two wing-tip tanks, each with the capacity to carry 76 L of fuel, all of which was usable.

The pilot provided a fuel receipt, which showed 389 L of fuel had been purchased on 1 July 2015 at Bundaberg. There was no evidence recorded on the maintenance release to show that the aircraft had been in Bundaberg that day. The pilot had recorded four flights from that date, including the incident flight, totalling 3 hours and 55 minutes flight time with four take-offs and three landings (not including the accident).

The pilot reported that the fuel consumption rate used for planning was 60 L per hour for the cruise, and 80 L per hour for take-off and the first hour. The pilot also stated that the fuel gauges indicated that about half fuel remained at the time of the accident.

ATSB comment

The pilot reported that about half of the aircraft’s fuel capacity remained at the time of the accident. However, the subsequent inspection found a total of about 2 L of fuel remained in the intact (and selected) right main fuel tank. The recovered engine data indicated that fuel starvation occurred at the time the engine stopped. The ATSB could not resolve the difference between the pilot’s account and the fuel state found after the accident.

Safety message

The pilot commented that if the aircraft had been higher on final approach, it would have been able to glide to the runway.

The ATSB research publication Starved and exhausted: Fuel management aviation accidents, states that accurate fuel management starts with knowing exactly how much fuel is on board at the commencement of each flight. It also relies on a method of knowing how much fuel the aircraft consumes. The likelihood of fuel starvation is reduced by adhering to procedures, maintaining a record of the fuel tank selections during flight and ensuring appropriate tank selections, particularly for take-off and landing.

Aviation Short Investigations Bulletin Issue 46

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

__________

1. Mayday is an internationally recognised radio call for urgent assistance.