At about 0725 Eastern Standard Time (EST) on the morning of 24 April 2016, the pilot of a Kavanagh Balloons B-400, registered VH-WNV (WNV), prepared to land at Rothbury near Cessnock, New South Wales (Figure 1). On board the scenic flight were the pilot and 16 passengers. The balloon was one of a number of balloons conducting a similar scenic flight that morning.
The pilot had selected a landing site, and informed the ground crew by radio, but the light wind carried WNV, and the other balloons in the group, a little further past this site. The pilot in WNV (and the other balloon pilots) then selected a nearby paddock for landing, and updated the ground crew accordingly. The pilot lined the balloon up to land, but then noticed a small dam along the intended landing path. The pilot manoeuvred the balloon over the dam before turning off the burners, and making a gentle landing.
Figure 1: VH-WNV landing area (green circle)
Source: Airservices Australia: Extract of Sydney World Aeronautical Chart, annotated by ATSB
The manoeuvring over the dam resulted in the balloon being a little closer to the tree line than ideal (Figure 2). Mindful that the ground crew had to pack up the 400,000 cubic foot balloon once the passengers has disembarked, the pilot advised them that they would move the balloon back about 10m further from the trees. To assist with this process, and make the balloon more buoyant, the pilot checked the neck of balloon was still sufficiently open, and then turned on the pilot light of one of the two burners.
Moments later, the pilot again checked the neck of the balloon and noticed the gentle wind had blown part of the deflating balloon back on itself and there was black smoke emanating from this area. The pilot then observed that some of the fabric had melted and had begun to drip onto the occupants of the basket. The pilot quickly re-directed the ground crew from the task of pulling the top of the balloon down, to assisting the passengers disembark and move away to a safe area.
To avoid any potential of the balloon becoming aloft during the disembarkation process, the pilot pulled the smart vent[1] to rapidly release air. The pilot reported it was difficult to assess the extent of the fire from the basket, but they were aware that the balloon envelope ‘sliding’ on itself was adding more fabric as ‘fuel’ to the fire.
The balloon envelope deflated and landed next to the basket. The pilot (still on board) and the ground crew, after ensuring the passengers were safe, discharged fire extinguishers. Within a few minutes, the crew were able to spread the balloon envelope out and extinguish the fire.
During the emergency disembarkation, two of the passengers received minor burn injuries. The lower section of balloon envelope was substantially damaged.
Figure 2: Kavanagh Balloons B-400, VH-WNV at Rothbury
Source: Pilot
Pilot comments
The pilot had logged over 1,330 flying hours, with about 350 hours on the Kavanagh Balloons B‑400.
In hindsight, the pilot advised that the decision to move the balloon back 10 m to assist the ground crew with the collapse and pack-up of such a large balloon was not the correct one. Other balloons landing nearby did not attempt to move their balloons away from the tree line.
Safety message
This occurrence highlights how quickly events may change. The simple decision by an experienced pilot to move the balloon back 10 m from the tree line to assist the ground crew inadvertently led to a fire.
The Federal Aviation Administrations’ (FAA) comprehensive Balloon Flying Handbook (2008) covers all aspects of balloon flying including aeronautical decision-making. Aeronautical decision-making is a systematic approach to the mental process used by pilots to determine the best course of action in response to a given set of circumstances. It builds on the foundation of conventional decision-making but enhances the process to decrease the probability of pilot error.
As almost all ballooning operations are conducted as single-pilot operations, ballooning uses a variant of crew resource management, known as single-pilot resource management. This integrates:
human resources
situational awareness
decision-making process
risk management
training.
One way in which the risk management decision path can be framed is through the perceive-process-perform model, which offers a structured way to manage risk.
– consequences posed by each hazard – alternatives that eliminate hazards – reality (avoid wishful thinking) – external factors (‘get-home-itus’).
Perform risk management:
– transfer – can someone be consulted? – eliminate – can hazards be removed – accept – do benefits outweigh risk? – mitigate – can the risk be reduced?
Other decision-making models are also covered in the manual.
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
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 15 April 2016, the pilot of a Cessna 172 aircraft, registered VH-VSO (VSO), was conducting a solo navigation training flight from Ballarat to Warrnambool, Portland, Hamilton and return to Ballarat, Victoria.
On the same day, two pilots, both instructors, were conducting a local training flight in a Cessna 177RG aircraft, registered VH-OOJ (OOJ), from Ballarat Airport. At about 1648 Eastern Standard Time (EST), while tracking south-east about 12 NM from Ballarat Airport, and at about 3,800 ft, the pilot in command, who was the pilot-not-flying and in the left seat, sighted VSO out of the right window about 100 to 200 ft below. The pilot in command then took control of the aircraft from the other pilot and commenced a steep climb. VSO then passed beneath OOJ. Shortly after, the pilots of OOJ heard the pilot of VSO broadcast on the common traffic advisory frequency, 10 NM west of Ballarat and inbound to the airport.
The pilot of VSO reported that they could not recall their altitude when about 12 NM west of Ballarat, but would normally be between 3,500 and 4,500 ft on descent. The pilot reported scanning the sky to look out for other aircraft, and maintaining a listening watch on the area and Ballarat common traffic advisory frequencies. The pilot did not hear any broadcasts from the pilots of OOJ and did not observe any aircraft in close proximity during the flight.
Pilot comments
Pilot in command of VH-OOJ
The pilot in command of OOJ reported both pilots were maintaining a general lookout for other aircraft. However, at a moment when the other pilot was pointing to one of the aircraft instruments, the pilot in command sighted VSO out of the right window. The pilot in command commented that while it is important to understand the instruments during endorsement training, this should not detract from the lookout for other aircraft.
Operator comments
Operator of VH-OOJ
The operator of OOJ commented that Ballarat is a very busy training airport with the training area to the west. Therefore, if pilots of aircraft arriving from the west broadcast prior to 10 NM from the airport, this may increase the situational awareness of pilots of other aircraft in the training area.
Safety message
This incident highlights the importance of using both un-alerted and alerted see-and-avoid principles and maintaining a vigilant lookout at all times.
The ATSB SafetyWatch highlights the broad safety concerns that come out of our investigation findings and from the occurrence data reported to us by industry. One of the safety concerns is safety around non-controlled aerodromes.
Research conducted by the ATSB found that, between 2003 and 2008, 181 occurrences of reduced separation in the vicinity of non-towered aerodromes were reported, of which 55 were near mid-air collisions (aircraft proximity events). Insufficient communication between pilots and breakdowns in situational awareness were the most common contributors to safety incidents.
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
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 21 April 2016, at about 1115[1], train 3MP5 (travelling from Melbourne to Perth) derailed while traversing the eastern points at Rawlinna. The points failed to restore to the normal position after the last train departed the loop line, leaving the points in an unsafe open position. The colour light point indicator system worked as designed by displaying a red indication when the points were unable to be detected and locked in a safe position.
There were minor injuries sustained by the crew. About 200 m of track infrastructure was damaged, and the main line between Adelaide and Perth was blocked until 1351 on 25 April 2016.
What the ATSB found
The ATSB found the driver’s expectation that the system was likely set for the main line contributed to train 3MP5 travelling at a speed where it could not be stopped before the open points. Additionally, it was likely a common practice for drivers to approach crossing locations without slowing when authorised for the main line. Compounding this was the points enhancer sighting distance being less than the effective braking distance of trains travelling at line speed, thereby increasing the risk of overrun if not displaying a green aspect.
The ATSB also found that the crew van did not meet the requirements of AS 7522-2012 - Railway Rolling Stock Access and Egress, since the occupant could not access any escape paths without external assistance and additional equipment.
What's been done as a result
Pacific National have reviewed operational instructions, audited enhancer sighting distances between Cook and Kalgoorlie, and reviewed emergency egress arrangements. The Office of the National Rail Safety Regulator will look further into the possibility of prescription glasses with progressive lenses altering the perception of signal colours.
Safety message
The common practice of approaching safety critical zones at higher speed probably affects multiple operators. The effective sighting distance of safety critical locations (enhancers, targets, etc) being less than the effective braking distance of trains represents a physical gap or limitation of the system. This limitation places more reliance on procedures to cover the gap. Although the Australian Rail Track Corporation and Pacific National have procedures in place, not all operators have the same requirements. Other operators may instead rely on one layer of procedural protection provided by the track manager, increasing the likelihood of an occurrence.
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.
Additional 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.
Office of the National Rail Safety Regulator (ONRSR)
As a result of the ATSB investigation, the ONRSR became aware of research papers and looked further into the possibility of prescription glasses with progressive lenses altering the perception of signal colours.
Pacific National
Pacific National advised the ATSB of the following proactive safety actions in response to the incident the subject of the Draft Report, for inclusion in the Final Report:
Following the incident, Pacific National issued Safety Share INT-NOT-SAF Share LSN 16-56 – Rawlinna Derailment, to Pacific National Intermodal personnel in WA.
Pacific National has conducted a Light Indicator (Enhancer) distance sighting analysis for the section of ARTC track between Cook, SA and Parkeston, WA.
Pacific National will provide ARTC with the Light Indicator (Enhancer) distance sighting analysis conducted for the section of ARTC track between Cook and Parkeston by Pacific National to determine what improvements can be made to improve sighting distances where required.
Pacific National will approach ARTC to promote improvements to track infrastructure that support driver decision making on the approach to self restoring motorised points, including the potential introduction of a system to issue a warning or alert to operators when the Self-Restoring Switch (SRS) system fails to restore correctly for the main line at all crossing locations between Cook and Parkeston.
Pacific National has completed the design of an additional emergency egress option for NR class locomotives through the front windows. Pacific National has commenced installation of the emergency egress windows on NR class locomotives and it is anticipated that the installation on all NR class locomotives will be completed by December 2017. In addition, consideration is being given to additional emergency egress options for other classes of Pacific National locomotives.
Pacific National has conducted a mainline risk assessment which includes assessment for train operations approaching facing points including the hazard of derailment and the associated identified controls.
Australian Rail Track Corporation (ARTC)
Australian Rail Track Corporation has undertaken the development and roll out of Advanced Train Management System (ATMS) Technology with a view to installing ATMS on the ARTC network between Tarcoola and Kalgoorlie. Australian Rail Track Corporation has invested significant effort and funding into the development of ATMS , a system which has the ability to identify and negate contributing factors to this incident. ATMS creates a safer operational environment by increasing the levels of control, detection and visibility available to Network Control Officers, provides system generated validations and warnings to Train Crews and has the capacity to initiate a brake application to arrest an unsafe condition if the condition is not recognised by or negated by the locomotive crew.
ARTC have undertaken to review the enhancers at Rawlinna recording the sighting distance, type and any obstructions impacting on sighting.
ARTC have undertaken discussions with train operators to reiterate the requirements of the ARTC Addendum to the Code of Practice for the Defined Interstate Rail Network Section 19 when approaching a location equipped with light indications and/or with points indications.
Appendices
Appendix A – Sequence of events
Safety analysis
Sighting distance versus braking distance
Train crew vigilance and effective indicator sighting distance are critical. The enhancer lights at Rawlinna consisted of an incandescent long distance (K3) search light. Depending on lens system, lamp, and ambient conditions, the K3 signal can attain a range of up to 2500 m in clean air. Any form of beam spread applied to a signal reduces its range. Based on the recollections of train crews (including 3MP5), the effective sighting distance of the eastern enhancer light is about 1000 m. ATSB investigators onsite measured about 1200 m sighting of the eastern enhancer light from ground level. This is dependent on time of day, weather, heat haze, direction of sun, and other environmental conditions.
Figure 7: Sighting from Rawlinna location board
Source: ATSB.
The ARTC use a train braking calculator[16] when determining braking distances of trains. The calculator specifies a full service braking application stopping distance of 2220 m for an 1800 m freight train, three quarter loaded and travelling at track speed of 110 km/h.
Train 3MP5 was approaching the location board at 104 km/h. Using the same parameters, the calculator specifies a full service braking distance of about 2050 m on level track. This equates to about 15 seconds for the train crew to make a full service brake application after passing the Rawlinna location board, Figure 7.
Figure 8: Sighting and braking distances
Source: ATSB.
Figure 8 illustrates a gap of about 1050 m between the minimum full service braking distance and effective sighting distance. In order for trains to approach at a speed at which they can stop, a brake application is required near the location board. Following this, it is inevitable that a train travelling at about 100 km/h at a sighting distance of 1000 m would not stop in time. Train 3MP5 was travelling at 102 km/h when the co driver called a red enhancer and the brakes were applied. This equates to a full service braking distance of about 1950 m on level track, considerably more than the 900 m available in this case.
When considering Pacific National’s train handling guidelines and safety critical zones, Pacific National trains should be braking at the location board in order to reduce speed to 50 km/h at the 1000 m point. This would allow trains greater time to slow or stop as required or until the condition of the points could be positively confirmed.
However, other train operators over this section of track may not have the same guidelines as Pacific National. The absence of advanced warning (such as a repeater enhancer) or other measures to manage train speed (such as permanent speed restrictions), places further reliance of drivers’ interpretation of what an appropriate approach speed is (in line with ARTC procedures) before sighting of the enhancer is possible.
Following the incident, Pacific National conducted an audit of enhancer sighting distances between Cook and Kalgoorlie, both east and west bound. The results of the audit found that about 50 percent of locations exhibited effective sighting distances of less than 2000m in daylight hours. Although sighting distances may not be ideal depending on local conditions, current rules and procedures, when followed, should address and increased risk.
Rules and routine violations
The ARTC use a master train plan (timetable) to manage/plan train movements on their network. The master train plan is a complete listing of all contracted path schedules and associated information for the entire ARTC network.
The master train plan relies on section running times between locations. The ARTC publishes indicative section running times to assist stakeholders.
The ATSB examined the ARTC section running times to ascertain if enough time was allowed for trains to safely traverse a section while complying with the ARTC rules and PN’s train handling guidelines.
The master train plan allows 23 minutes for trains to travel the 33.5 km long section between Wilban and Rawlinna. This equates to an average speed of 87 km/h throughout the section, well below the track speed of 110 km/h.
The section between Wilban and Rawlinna was then divided into operational zones (Figure 9) to determine the appropriateness of the section running time. Given the difference between braking distance and effective sighting distance of the enhancer, the braking zone is compressed into a full service application at the location board. In reality, this is not consistent with best practice driving principles. Best practice driving involves predictive driving, anticipating braking requirements well in advance.
The section running time of 23 minutes for train 3MP5 was analysed as shown in Figure 9.
Figure 9: Section time analysis
Source: ATSB. Not to scale.
The analysis concluded that the section running time allowed for train 3MP5 between Wilban and Rawlinna was likely adequate for normal running. The section running time did not include extra time for adverse weather or other conditions that might affect train-running speeds.
The ATSB also examined recorded data so as to understand the common behaviour of trains approaching crossing locations. The data was derived from the Rawlinna ICAPS GPS data for the period between 14 April 2016 and 21 April 2016 (seven days leading up to the incident).
Train speeds were examined over the section beginning 6 km prior to the enhancer/points. Movements outside of daylight hours were excluded due to enhancer conspicuity and increased sighting distance. The results are shown in Figure 10.
Figure 10: Approach speed analysis results
Source: ATSB.
The results indicate that 79 percent of daytime trains (passing through Rawlinna) do not slow down before the effective sighting of the enhancer, both east and west. This meant that trains were approaching Rawlinna at a speed where the train crew cannot ensure stopping at the points if the enhancer is not indicating the road is correctly set for the main line, or it was incorrectly read.
Although this analysis focused on data from Rawlinna, it is likely that this is common practice for most trains traversing other crossing locations where self-restoring points and enhancers/point indicators are installed. This common practice is not consistent with the ARTC addendum to the CoP (dated 4 October 2015) section 19 Maximum Train Speed for Particular Locations and Circumstances.
Furthermore, this common practice may involve multiple operators, other locations, and varying operational circumstances increasing the likelihood of an occurrence.
Train handling
The crew approached Rawlinna with authority to pass through on the main line. There was no requirement to interact with the ICAPS system. Therefore, the crew had the expectation that the points were correctly set and they could continue as per their authority. Unbeknown to the train crew, the points had failed to self-restore to the normal position after the last train 4PS6. This meant that the protection of the points relied solely on the vigilance of the train crew, defensive train handling techniques, ARTC procedures; and the sighting distance of the enhancer light, the last lines of defence.
Factors affecting crew actions
Train driving is a complex task performed in a dynamic environment, requiring the processing of information from outside the cab (eg. signals, speeds, landmarks) combined with a detailed body of experientially acquired route knowledge to effectively control the train. Efficient train handling demands sustained attention over long time periods wherein the driver must respond to current task demands whilst also using higher level cognitive processing to plan ahead with mental time-distance estimations.[17][18] Furthermore, this demanding role is also often performed in a time constrained organisational context.
Both route knowledge and two driver operations are widely considered to be key defences for human performance limitations as they apply to train driving.
Route knowledge and expectancy
Expectancy can be understood as the extent to which an event or condition is expected to occur or be present at a particular time and place. An individual’s expectation can influence their attention to (and preparation for) that event or condition[19]. In this case, the train crew said they did not expect to have the colour light points enhancer at red as they were traveling through on the main line. Thus, it can be interpreted that the crew had, through considerable experience, come to trust that the automated points activation system was highly reliable. They had no expectation that they would encounter any issues with the points activation, and anticipated that the enhancer would be displaying steady green as they approached.
This effect is consistent with automation research which has found that systems which have been shown to be reliable can create an effect of over-trust. People will over-depend on the automation, and pay less attention to the true behaviour of the system (in this case, the points and points indicator) which is being controlled by the automation.[20]
Both drivers’ previous experience of the area, as well as their trust in a normally reliable automated system created an expectation that the points would be set, detected, and locked for the main line.
The driver’s expectation that the signalling system was likely set for the main line, contributed to the overrun of the points.
Train crew emergency evacuation
The Rail Industry Safety and Standards Board (RISSB) of Australia is responsible for the development, maintenance and management of the rail industry’s:
Standards
Codes of Practice
Rules, and
Guidelines.
RISSB develop these products using input from rail experts from across the rail industry to represent good practice for the industry in Australia. The standard relevant to emergency evacuation is AS7522-2012 Australian Standard - Railway Rolling Stock Access and Egress, and is provided in three parts:
Part 1: Locomotive Rolling Stock
Part 2: Freight Rolling Stock
Part 3: Passenger Rolling Stock
Locomotive
For locomotives, Part 1, Section 6.2 New and Modified Rolling Stock[21] states:
Enclosed cabs of new and modified rolling stock shall be fitted with sufficient emergency exits to provide escape paths to the vehicle exterior when the vehicle is upright and when overturned on the side.
A suitable solution is for emergency exit windows on each side and another emergency exit either in the front or rear of the compartment.
The NR class locomotive has an enclosed cab. Access and egress to the cab was via a single door to a central vestibule, and two doors to the outside of the locomotive (Figure 11). This access was also the primary emergency escape path. Although the construction of the NR class locomotive (NR34) occurred prior to the publication of the RISSB Standard AS 7522, Pacific National had included the identification of an alternate escape path through the locomotive cab side windows. The alternate escape path was available after sliding open the side windows.
Figure 11: NR class locomotive cab access/egress schematic
Diagram of NR class locomotive primary emergency egress path (in red) through centre vestibule and rear side doors. Source: Pacific National Annotated by ATSB.
Following the derailment on 21 April 2016, locomotive NR34 came to rest on the co-driver’s side (right side in direction of travel). Both drivers were thrown into the side of the cab (Figure 12).
Pacific National advised that the emergency escape paths/arrangements to evacuate from a locomotive were part of the training delivered during trainee development. The effectiveness of this training for an escape from a situation where a locomotive had tipped was not evident.
Although the emergency escape paths from an NR class locomotive provided options, these options became less accessible with the locomotive on its side.
In the derailment of train 3MP5, both identified escape paths necessitated the crew climbing on internal structures to facilitate egress. The minor injuries sustained by the drivers did not overly affect their escape in climbing up through the cab and out of the side window (now on top).
Figure 12: Locomotive NR34 cab
Image showing resting position post derailment. Source: ATSB
Crew van
The RISSB standards for railway rolling stock define passenger rolling stock as vehicles that carry people and facilities for these people[22]. Consequently, a crew van is generally considered to be a passenger vehicle and the relevant standard for access and egress is AS 7522 Part 3: Passenger Rolling Stock. This standard stated:
Enclosed cabs of new and modified rolling stock shall be fitted with sufficient emergency exits to provide escape paths to the vehicle exterior when the vehicle is upright and when overturned on the side.
The crew van consisted of a modified FAM passenger coach. The original FAM configuration contained nine twin sleeper berths. The reconfigured FAM wagon (circa 2012) contained six sleeping berths and a common area containing and entertainment area and kitchen area. The FAM wagon is used by resting train crews.
The crew van is a steel-framed car, has a stainless steel body and rides on all-steel two-axle bogies. Metal-framed rectangular windows are evenly spaced down the sides of the carriage. Vehicle access is via two external side doors into a central vestibule, and a vehicle end door (Figure 13). The external doors were also the primary emergency escape paths. A supplemental escape path through side windows was available after removing the window, and lowering an emergency ladder out of the window.
Figure 13: FAM crew van layout and exits
Image showing internal layout of the crew van. Source: Pacific National
Following the derailment, the crew van came to rest on its left side in direction of travel. The resting driver was thrown around inside of the van (Figure 14) and received facial lacerations from a lunch box.
Figure 14: Crew van resting position
Image showing resting place of the crew van. Source: ATSB.
The driver in the crew van could not access the primary escape paths. Similarly, since the vehicle was on its side, the driver could not reach the emergency push-out window, so remained trapped. Both drivers (from the locomotive) tried to assist the driver in the crew van. Initially, the emergency window accessing the dining area was smashed and the emergency ladder deployed (Figure 15).
Figure 15: Crew van emergency ladder
Image showing emergency exit ladder inside the crew van. Source: Driver of 3MP5.
Unfortunately, the ladder was only designed to be deployed to the ground outside the window, providing effective egress from a wagon in an upright position. In this case, the wagon was on its side and the mounting position of the ladder made it ineffective as a method to allow escape. Consequently, the resting driver remained trapped in the crew van until an ARTC worker (who attended the incident site) could provide a standard step ladder (Figure 16).
Figure 16: Crew van evacuation
Image showing step ladder used to extricate the driver from the crew van. Source: Driver of 3MP5.
It is evident that, in this case, the crew van did not meet the requirements of AS 7522 since the driver could not access any escape paths without assistance and additional equipment.
From the evidence available, the following findings are made with respect to the derailment of train 3MP5 at Rawlinna, Western Australia, on 21 April 2016. 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 eastern points at Rawlinna failed to fully transition for the main line.
The driver’s expectation that the system was likely set for the main line contributed to train 3MP5 travelling at a speed where it could not be stopped before the open points.
Other factors that increased risk
It is likely a common practice for drivers to approach crossing locations without slowing when authorised for the main line.
The points enhancer sighting distance is less than the effective braking distance of trains travelling at line speed, thereby increasing the risk of overrun if not displaying a green aspect.
The crew van did not meet the requirements of AS 7522-2012 - Railway Rolling Stock Access and Egress, since the occupant could not access any escape paths without external assistance and additional equipment.
Other findings
The failure of the points to operate to normal could not be established. However, the colour light point indicator system worked as designed by displaying a red indication when the points were unable to be detected and locked in a safe position.
It is unlikely that fatigue adversely affected the crew’s performance during this shift.
There was no evidence to suggest that any medical or physiological factors affected their performance leading up to or during the incident.
The section running time allowed for train 3MP5 between Wilban and Rawlinna was likely adequate.
Context
Location
Rawlinna is a crossing loop located at the 1403.000 km[5] point on the interstate rail network in Western Australia. Train movements are managed by the ARTC from Network Control Centre West located at Mile End, Adelaide, South Australia.
Environmental conditions
At the time of the occurrence the weather was dry, with temperature about 21 °C and 55 percent humidity. The sky was slightly overcast with about 1/8 cloud cover. The sun was at about 45 degrees in the north.
Considering the conditions, sighting and conspicuity of the colour light enhancer or points indicator had not been adversely affected at the time of the occurrence.
Train and crew information
Train 3MP5 was an intermodal freight service operated by Pacific National between Melbourne and Perth via Adelaide. The train departed Melbourne on 19 April 2016 and arrived in Adelaide the following day.
On departure from Adelaide, the train consisted of locomotives NR 34 (leading) and NR 50 (trailing) hauling 32 wagons for a total length of 1693 m and gross mass of 4343 t.
Based on an analysis of the available evidence, the condition and serviceability of train 3MP5 did not affect its handling at the time of the occurrence and was not considered a factor in the derailment.
Train crew
At the time of the occurrence, the driver and co-driver of train 3MP5 had extensive railway experience working on the interstate rail network between Cook and Kalgoorlie.
The driver and co-driver were qualified in the operation of the locomotives, the ARTC Code of Practice (CoP) and in route knowledge for the portion of the network between Cook and Parkeston.
Toxicology, medical and physiological factors
Upon returning to the Pacific National offices at Kalgoorlie at about 2140, the crew submitted to a screening test for the presence of alcohol and drugs. Each crew member tested negative to the presence of alcohol and drugs.
An examination of the driver’s and co-driver’s health assessment records confirmed that their health assessments were current and that the individuals had been assessed as meeting the required standard, prescribed by the National Standard for Health Assessment of Rail Safety Workers. There was no evidence to suggest that any medical or physiological factors affected their performance leading up to or during the incident.
Fatigue
Fatigue can have a range of influences on performance, such as decreased short-term memory, slowed reaction time, decreased work efficiency, reduced motivational drive, increased variability in work performance, and increased errors of omission. Fatigue impairment has been identified as a contributing factor in accidents such as this.
The crew had worked train 3PS6 from Kalgoorlie (sign-on 0250) to Cook (sign-off 1605) in the previous day (20 April 2016). They went to their designated accommodation in Cook, had dinner, and then went to bed. On the following day, the crew signed on for duty at 0540 (WST) for a 0602 departure as the ‘working out’ crew. Because the anticipated travel time was less than 12 hours, the crew worked ‘two-up’, with the third driver remaining in the crew van.
The duration of the off duty period meant that there was sufficient opportunity available for the crew to attain restorative sleep prior to commencing work. The drivers each advised that they had a good night’s sleep and felt well rested when they commenced duty. Therefore, it is unlikely that fatigue adversely affected the crew’s performance during this shift.
Safeworking system
The ARTC managed the safe movement of trains on the section of the network between Cook and Parkeston via a verbal communications based Train Order Working system (TOW). The system required the NCO to issue an authority to the train crew, who then recorded the authority on a paper based Train Authority (TA) form. The content is validated by reading the TA back to the NCO. The TA, once validated, authorised the train to proceed between the specified locations and in accordance with any additional instructions.
The train crew of 3MP5 executing the TA were required to comply with instructions contained in the TA together with the applicable rules and procedures contained in the ARTC Code of Practice for the Interstate Rail Network (CoP) and ARTC Addendum to the Code of Practice for the Defined Interstate Rail Network (Addendum) version 4.3 dated 4 October 2015.
Train Authority rules and procedures
The NCO could issue a TA that authorised the crew to travel over a series of consecutive track sections that included a number of crossing loops or other locations. To enable the coordination of other train movements, the NCO may also request that the train crew report the times of their arrival or departure from specified locations en route.
Points indicator and remote control systems
Rawlinna was equipped with two systems to indicate the position of the self-restoring motorised points to approaching trains. Each set of points had a points stand indicator (Table 1) that was mechanically connected to the points mimicking the position of the points. It displayed whether the points were in the reverse (crossing loop line) or normal (main line) position and was reliant on approaching trains having a line-of-sight to the target.
Table 1: Points stand indicator target aspects
Points enhancer
In addition to the points stand indicator, a colour light indicator called the points enhancer was installed next to the points stand indicator. The enhancer indicates the position of the points and provides some additional (or enhanced) information. Due to sighting limitations caused by obstructions at some locations, repeaters can be located (about 2500 m before the enhancer) that 'repeat' the indicator aspect (colour) of the enhancer in order to give advance warning of its condition. Rawlinna did not have repeaters installed.
The indications displayed by the enhancer[6] are shown in Table 2.
Table 2: Colour light points enhancer aspects
The colour incandescent light of the enhancer is more conspicuous than the mechanical points stand indicator target. It also provides additional information on the lay of points at the other end of the crossing loop.
If the points at both ends of the loop are correctly set for the main line (as was intended in this case), the points enhancer would display a steady green indication. However, if the points do not fully transition for access onto the main line, the enhancer will display a red indication (as occurred in this case). The required action at a red indication is to stop and inspect the points.
The ARTC Addendum to the CoP (date 4 October 2015) states:
Where possible, following departure observe that the points have restored for the main line and a steady green aspect is displayed by the light indicator.
The intent of this requirement is to identify any failures before the passage of the next train. In this case, train 4PS6 was the last train to depart the eastern end of Rawlinna loop. However, given the length of the train (1552 m), train exit speed and the distanced travelled it may not have been possible for the crew to observe the points or light indicator via the locomotive driver's mirrors once the train had completely cleared the loop and the points have completed the intended function and returned to the normal position.
Radio remote control points operation
The crossing loop at Rawlinna was installed with radio remote control, self-restoring points. The system allowed drivers to select the loop line when approaching Rawlinna. The points would automatically return (self-restore) to the normal (main line) position after the train has fully entered or departed the loop line.
Drivers are required to transmit (by an in-cab activated points system [ICAPS]) a designated command to initiate the points control sequence. The points enhancer would display red and, after a 120 s time delay, the points would move for access into the crossing loop. When the points were detected in the correct position and locked for the loop line, the indicators would display a flashing yellow light and the train could pass into the loop line. If the points are not detected fully home and locked, the indicator would remain red and trains would be required to stop short (clear) of the points.
The ARTC addendum to the CoP (dated 4 October 2015) section 6.9.2 states:
There is no requirement to enter a command to set the points for the main line.
The operation of the ICAPS equipment does not remove the responsibility of the train crew to ensure that the points are correctly set by observation of the Light Indicator and Point Indicator.
Section 6.9.2.1 further reiterates:
Train crews should not assume that the entry of the loop command will set the points for the crossing loop and shall control the movement prepared to stop at the facing points unless the point indicator is displaying that the points are correctly set for the movement.
Section 6.9.2.2 confirms:
If the movement is not required to select the loop, the driver is not required to take any action and shall proceed in accordance with the instructions on the train authority.
In this case, there was no requirement for the crew (train 3MP5) to operate the ICAPS equipment as their authority was to take the main line. The ARTC addendum to the CoP (dated 4 October 2015) section 19 Maximum Train Speed for Particular Locations and Circumstances states:
b. At the location sign in advance of a location equipped with light indications and/or with points indications.
The train shall reduce speed, and be prepared to stop before the facing points. The maximum speed may be maintained or resumed when the Train Crew has confirmed that the correct indication is displayed.
Regardless whether the ICAPS is used or not, section 19 places a restriction on the approach speed of trains.
Post incident testing
Following the derailment, mechanical and electrical inspection and testing was conducted on the points. An initial assessment was conducted on the day of the incident and found that the equipment worked as designed. Examination of the electrical equipment data logs confirmed the enhancer indicator restoring to a red display, the run-down timer, movement and eventual timing-out of the action after the points had not reached the normal position, and the ICAPS transmission to train 3MP5.
A number of follow up tests confirmed that the points were mechanically correct and within specified operational tolerances. The ARTC could not identify a cause for the points failing to operate to normal. However, the system worked as designed and failed to a safe condition by maintaining the indicator at red after the points had not moved fully to the normal position.
The equipment at Rawlinna had been regularly maintained in accordance with the ARTC standards. The next scheduled inspection of the equipment was due on the day of the derailment.
Pacific National systems
In-cab activated points and GPS location alerter systems
The Pacific National NR Class locomotives were fitted with In-Cab Activated Points System (ICAPS), and the Pacific National AWARE[7] and GPS location alerter systems. The systems were interconnected to provide the required functionality.
The ICAPS enables the remote operation of the self-restoring point machines[8] at crossing loops by the crew from the locomotive cab, allowing train crews to set the required route without having to stop the train. ICAPS activation occurs at a strike-in point (generally 5 to 8 km from the facing point at each crossing location) and remains active for a distance of about 2 km, providing a window within which the crew can remotely operate the points. The functionality to operate the points is deactivated once the train is outside this window. Pushbutton controls located adjacent the point machine are available if a train is required to stop for the crew to manually operate the points.
When ICAPS is activated, a screen in the locomotive cab displays a message showing the location name and two touch-screen buttons. An audible tone accompanies the message to alert the driver that the system is active. If a loop movement is authorised, the crew can command the points to set for the crossing loop. If a main line movement is authorised, the crew can dismiss the message and leave the points in their current position (usually set for the main line). Similarly, if the crew take no action, the points will remain in their current position.
The GPS location alerter system is an enhancement to the AWARE system that provides track position information to the train crew when approaching a crossing loop or block point location.[9] The purpose of the system is to ‘prompt the train crew to check their current limit of authority’.[10] If the crew has already made an ICAPS selection for the loop, the alerter will not activate since the crew has taken action relevant to the train authority.
The GPS location alerter system displays a message on the AWARE screen when the locomotive is about 5 km from the crossing location. A single audible beep is also sounded, but under the ARTC CoP there is no requirement to acknowledge the message.
When a locomotive is within 3 km of the crossing location, the system sounds three audible beeps and a message on the AWARE screen. For this alert, the system requires acknowledgement within 10 seconds using the AWARE system touchscreen located adjacent the co-driver’s position. If not acknowledged, the audible beeps continued with increasing volume until actioned or if the train has travelled 3 km past that particular crossing location.
When the locomotive is about 3 km past the crossing location, the AWARE screen displays a message identifying the name and track kilometre point for the next crossing loop. This message is not accompanied by an audible tone and there is no requirement to acknowledge it.
Together, this combination of systems provides a sequence of messages and audible alerts to the train crew at each location traversed. The systems do not have (nor are they required to have) the functionality of providing real time train location information to network control. Similarly, the systems do not provide information relating to the condition of the points.
Safety critical zones
A strategy used by some Australian rail operators to enhance train crews’ threat and error management is the identification of ‘safety critical zones’.[11] A safety critical zone is generally identified as a set time or distance on approach to a known higher risk phase of the trip, such as a stopping location, or limit of authority. While in the safety critical zone, the crew restricts all attention, actions, and communications to safety critical functions to the exclusion of other non-critical tasks or communications. Ideally, on entering the safety critical zone, the crew would also conduct a briefing to confirm each crew member’s responsibilities during this period, thus verifying assumptions and expectations before proceeding.[12]
The Pacific National document Defensive Train Handling Techniques and Strategies provided general advice for the safe working and operation of Pacific National intermodal services throughout Australia. The document defined a safety critical zone (Figure 5) and specified the need for train crew to restrict all their actions and attention to safety critical communication, and appropriate defensive driving and train handling techniques within this zone, to ensure that they stop the train prior to the designated stopping point.
Figure 5: Pacific National Safety Critical Zone
Source: Pacific National, enhanced by ATSB.
Sun glasses
The driver stated that on this occasion, he was wearing prescribed sunglasses supplied by an ophthalmic retailer through Pacific National. The lenses were tinted grey and not polarised, Figure 6.
Figure 6: Prescribed tinted sunglasses
Source: ATSB.
An ophthalmic retailer website[13] states that grey tinted lenses:
Grey - reduces brightness and glare, a neutral tint that transmits colours so they retain their true beauty. Best for bright outdoor sunlight to help reduce squinting and eyestrain
The driver had last undergone a medical assessment on 25 May 2015. This assessment included vision and colour blindness testing, requiring ‘normal colour vision’ for identifying point sources such as signals. The driver was declared fit for duty without restriction.
Given the driver’s fitness for duty and no evidence of colour interference from a grey tint, it is likely that the prescription sunglasses worn by the driver did not affect the colour transmission of the red indicator. It is plausible that other factors such as distance, heat haze, and expectation may affect the interpretation of a red indicator.
As a result of the ATSB investigation, the Office of the National Rail Safety Regulator (ONRSR) reviewed literature regarding misperception of signal colours. Studies conducted by Hovis (2011)[14] concluded that the North American and European standards did not meet the requirements for the railroad in the Canadian environment. The Australian/New Zealand standard also did not meet all the requirements for the railroad environment.
Further studies had been conducted which showed that in addition to tint, other properties of lenses could cause red railway signals to be perceived as yellow. When conducting a study in this field, Wood et al, (2005)[15] reported concerns by a Queensland Rail train driver that yellow signals appeared to be red when viewed through graduated lenses. A subsequent study found that the colour misperception occurred with both progressive-addition lenses and lenses with small amounts of positive defocus.
The sources of information during the investigation included the:
Australian Standards
Australian Rail Track Corporation rules, procedures, and standards
Pacific National rules, procedures, and standards
Recorded data
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 Pacific National, the Australian Rail Track Corporation, and the Office of the National Rail Safety Regulator.
Submissions were received from Pacific National, the Australian Rail Track Corporation, and the Office of the National Rail Safety Regulator. The submissions were reviewed and where considered appropriate, the text of the report was amended accordingly.
The occurrence
At 0540[2] on 21 April 2016, the crew of Pacific National (PN) train 3MP5 signed on duty at Cook for departure to Kalgoorlie. At about 0602, after attending to locomotive fuelling and paperwork, the train departed Cook under train authority W16 to Deakin. The train was crewed by three drivers, a driver operating, a co-driver observing, and a driver resting in the crew van.
Train 3MP5 continued its journey towards Perth on its scheduled timetable. At about 0632, just west of Denman, the driver performed a running-brake-test, testing the effectiveness of the train brakes.
Figure 1: Location of Rawlinna crossing loop and other referenced locations
Source: Geoscience Australia, annotated by ATSB.
Over the next 2 hours, train 3MP5 continued towards Loongana, having received further authorities at Deakin and Forrest.
At Rawlinna, an east bound freight train (4PS6) had entered the crossing loop at about 0900. About eight minutes later, another freight train heading west (3MP9), passed through Rawlinna on the main line.
Shortly after at 0910, authority W37 was granted to 3MP5 for the section between Loongana and Nurina. Near Loongana, the observing driver took control of train 3MP5 and the outgoing driver was now observing in the co-driver position. The resting driver remained in the crew van.
As train 3MP9 cleared Rawlinna on the main line heading west, train 4PS6 departed from the Rawlinna crossing loop heading east for a planned crossing with 3MP5 at Haig. At 0915, after train 4PS6 cleared the eastern points, the points activated a ‘self-restoring’ mode whereby the points would return to the normal position for main line movements. After 2 minutes, the points control system had not restored the points to the main line, and as a result the enhancer[3] indicator light remained at red.
Meanwhile, train 3MP5 continued west towards Rawlinna. At 1015, authority W45 was granted to 3MP5 for the section between Haig and Boonderoo (81 km beyond Rawlinna). About 20 minutes later, train 3MP5 passed through Haig on the main line with train 4PS6 standing in the crossing loop[4]. The train continued, passing through Wilban on the main line at 1056.
At about 1110, approximately 8 km from Rawlinna, the crew acknowledged a message from the In Cab Activated Points System (ICAPS). As 3MP5 held a train authority to pass through Rawlinna on the main line, there was no requirement for any points control action to be sent via the ICAPS.
At about 1113, train 3MP5 passed the Rawlinna location board, positioned about 2600 m from the eastern end of the crossing loop points, travelling at 104 km/h.
A little further on, the driver called a green light on the enhancer at Rawlinna then double-checked the authority with the co-driver. The co-driver confirmed the authority was to proceed to Boonderoo via the main line. The driver checked the train for any irregular operation through the rear vision mirrors. A short time later, both drivers noticed the enhancer at the same time. The co-driver commented that the enhancer was showing red. The driver, who was wearing prescription tinted sunglasses, thought to himself that the enhancer was showing a steady yellow. Because the co-driver had called a red indication, the driver started to apply the train brakes. Both drivers commented that they thought the points were set for the mainline, as they could see the green arrow on the mechanical indicator.
The driver removed his glasses and immediately realised that the enhancer was displaying a red light. The driver continued to apply the brakes as the train approached the points, by which time the co-driver commented that he could now see ‘some yellow of the dumb bell’, indicating that the points may not be correctly set (Table 1).
Train 3MP5 was unable to stop and, at 1114:56, it travelled over the points (Figure 2) at 90 km/h and derailed. The train continued to travel derailed for a further 160 m, coming to rest between the main and loop lines. Both locomotives and the crew van tipped onto their sides. The following six wagons, totalling 389 tonnes and 450 m in length, all derailed. Most of the wagons jack-knifed into an area about 140 m in length (Figure 3).
Figure 2: Open points at Rawlinna – as seen from 3MP5.
Graphic derived from the General Electric LocoCAM showing the Rawlinna eastern points in an open condition. That is, the points are not closed for either the main line (straight through) or the loop line (diverging to the right). Source: Pacific National
At 1117, the crew, after checking themselves, notified train control. After initially having difficulty, they evacuated by climbing up inside cabin, through the side window, then down over the front of the locomotive. After exiting the cab, they started back to check on the condition of the resting driver in the crew van. The Network Control Officer (NCO) in train control notified a local Australian Rail Track Corporation (ARTC) track patroller in the vicinity to attend and help. Dangerous goods were on the train but were not involved in the derailment.
The position of the crew van made it difficult to reach the resting driver. The co-driver climbed onto the side of the crew van and smashed a side window to try to gain access to the resting driver, who was conscious, but had received moderate head and body injuries and, initially, was unable to be extricated from the wreckage. By this time the ARTC track patroller was on site and assisted with the extrication of the resting driver from the wreckage.
A registered nurse from a local property attended and rendered first aid to the resting driver. All three drivers were transferred back to their home depot at Kalgoorlie, signing off duty at 0030 on 22 April 2016.
Figure 3: Wreckage at points
Source: ATSB.
Figure 4: Front of train
Source: Pacific National co-driver,
Post derailment
About 200 m of track was damaged, including the points. The ARTC built a track deviation to the south around the wreckage in order to allow rail traffic pass while recovery works were undertaken. The deviation was completed and the track, main line only, was reopened to allow rail traffic to pass at 1351 on 25 April 2016.
Purpose of safety investigations & publishing information
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
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 15 April 2016, at about 1400 Western Standard Time (WST), the student pilot of a Piper PA-28-181 aircraft, registered VH-BYE (BYE), departed from Jandakot Airport on a solo navigation training flight to Bunbury Airport, Western Australia. At about 1500, when about 10 NM north of Bunbury Airport, the pilot broadcast on the common traffic advisory frequency (CTAF) that they were inbound for a straight-in approach to runway 07.
At the time, a Cessna 152 aircraft, registered VH-CRP (CRP), was conducting circuit training at Bunbury Airport. On board CRP were an instructor and a student pilot. The active runway at Bunbury was 07, and the crew were broadcasting on the CTAF when on the downwind, base and final legs of the circuit.
The instructor of CRP heard the pilot of BYE broadcast inbound at 10 NM to the north. About 5 minutes later, the instructor heard the pilot of BYE broadcast they were joining a long final approach for a straight-in approach to runway 07. CRP was then on final approach for runway 07 and expected BYE to be behind them, but the pilots did not see BYE. The pilot of BYE heard the student pilot of CRP broadcast they were on final approach for runway 07, but also did not see the aircraft at that time.
After completing a touch-and-go landing, CRP was upwind of runway 07, at about 300 ft above ground level, when the student sighted an aircraft ahead and alerted the instructor. The instructor sighted BYE on a reciprocal track – on short final for runway 25, and took control of the aircraft from the student. The instructor of CRP took avoiding action, turning right, and BYE passed about 50 to 100 ft below and to their left.
When on final approach, at about 400 ft above ground level, the pilot of BYE sighted the numbers marked on the runway threshold, and realised they were approaching runway 25 instead of 07. At the same time, the pilot saw CRP pass to their left. The pilot of BYE conducted a slight right turn and commenced a climb to 1,500 ft.
After the incident, both aircraft landed on runway 07.
Pilot comments – pilot of VH-BYE
This was the pilot’s first solo navigation exercise. The pilot had done one touch-and-go at Bunbury about 4 weeks prior to the incident. The pilot had a briefing with their instructor prior to departing Jandakot, and discussed options for joining the circuit at Bunbury. The pilot had initially intended to join on the downwind leg of the circuit for runway 07, and could not recall why they amended the plan to make a straight-in approach.
ATSB comment
Pilots are encouraged to carefully consider options for joining the circuit during operations at non-towered aerodromes. With respect to straight-in approaches, Airservices Australia Aeronautical Information Package En Route 1.1 – 49.6 Straight-in Approach stated that ‘Straight-in approaches, whilst not prohibited, are not a recommended standard procedure’.
Straight-in approaches often limit the opportunity for a pilot to sight other circuit traffic, and join the circuit in a manner that avoids inconveniencing other traffic. Importantly, straight-in approaches also limit the opportunity for a pilot to effectively assess the aerodrome conditions and the status of movement areas, and identify any unexpected hazards.
Safety message
Following receipt of a broadcast from another aircraft in the vicinity, pilots should carefully assess the significance of the information in the context of their own intentions. In the event that potentially conflicting traffic cannot be visually identified, pilots should communicate accordingly and adopt a conservative course of action.
This incident highlights the importance of thorough pre-flight planning and preparation. The Flight planning kit – always thinking ahead, available from CASA’s online store, can assist pilots in preparing for flight.
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
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 18 April 2016, at about 1030 Eastern Standard Time (EST), a Lancair ES aircraft, registered VH-DFH (DFH), was taxiing to depart from a private airstrip about 22 km NW of Mansfield (ALA), Victoria. The pilot was the only person on board the private flight.
After conducting an engine run-up, the pilot taxied the aircraft to take-off towards the east on the sealed strip. The pilot reported that the engine run-ups, taxi, and take-off were normal. During the initial climb, at about 500 ft, the engine suddenly lost power and the pilot established the aircraft in a glide, reducing the throttle and looked for a suitable forced landing area. Some engine power returned but was very intermittent and the engine was not producing the correct power for the engine control settings.
The pilot advised that conducting a forced landing straight ahead would have involved negotiating houses, trees, livestock, and the unknown nature of the ground surface. They assessed that sufficient height was available to return to the airstrip so commenced a turn to the left.
The pilot lined up with the airstrip landing towards the west. As the pilot considered that the aircraft had good height and speed, the pilot elected to extend the flaps half-way and subsequently extended the flaps to the full down position as the pilot was concerned that the aircraft would overshoot the airstrip.
The aircraft touched down about 25 m before the threshold on a grass area. The aircraft bounced slightly, touching down again on the grass area beside the airstrip. The left wing contacted an electric fence post and came to a stop a further 100 m after the initial touch down point (Figure 1). The pilot exited the aircraft after turning off all the electrical and engine controls. The pilot was not injured and the aircraft had minor damage.
Figure 1: DFH at the accident site
Source: Aircraft owner
Pilot comment
The pilot reported that the aircraft was inspected subsequent to the incident at an aircraft maintenance facility and no defects were found with the aircraft or engine. The maintenance personnel assessed that fuel starvation[1] was the probable reason for the power loss due to the way the aircraft had been parked on an incline prior to taxi and take-off. The pilot reported that the aircraft has two independent fuel tanks, one in each of the slim line wings. During the pre-flight inspection, the aircraft was situated with the left wing on the downhill side for a little over half an hour. It is believed that the fuel drained away from the fuel pick up toward the wing tip through a one-way flapper valve[2] reducing the quantity of fuel available in the sump area where the left wing fuel pick up is located. The pilot reported that the left fuel tank had been selected for the taxi and take-off.
The pilot reported that a self-briefing was routinely conducted before each flight for possible emergencies with decision points and suitable emergency landing areas considered.
The pilot indicated that the wind speed was about 10 knots gusting to about 25 knots from the NE which may have contributed to an undershoot of the airstrip.
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.
Aircraft owner
As a result of this occurrence, the aircraft owner has advised the ATSB that they are taking the following safety actions:
The owner is considering installing a placard in the aircraft to remind pilots when the aircraft is parked on an incline to consider which fuel tank to select for take-off.
During and after take-off, a partial power loss is three times more likely in today’s light single‑engine aircraft than a complete engine failure. There have been nine fatal accidents from 2000 to 2010 as a result of a response to a partial power loss compared with no fatal accidents where the engine failed completely. Analysis of the occurrences supports the need to raise greater awareness of the hazards associated with partial power loss and to better train pilots for this eventuality.
The booklet highlights the importance of:
pre-flight decision making and planning for emergencies and abnormal situations for the particular aerodrome including a thorough pre-flight self-brief covering the different emergency scenarios.
conducting a thorough pre-flight and engine ground run to identify any issues that may lead to an engine failure.
taking positive action and maintaining aircraft control either when turning back to the aerodrome or conducting a forced landing until on the ground, while being aware of flare energy and aircraft stall speeds.
Further information about the wing fuel tank one-way flapper valve is contained in an article published by the Lancair Owners & Builders Organisation, Fuel system inspection & calibration and is available from their website. The article discusses how the flapper valve prevents fuel from flowing away from the inner most fuel compartment where the engine fuel supply line is located. It also discusses how the small wing dihedral makes the aircraft particularly sensitive to the outward flow of fuel.
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
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 15 April 2016, an instructor and student of a Grob G115C2 aircraft, registered VH-ZTA (ZTA), were conducting a local training flight in the training area south of Jandakot Airport, Western Australia. Two aerodromes were situated in the training area – Serpentine and Murray Field, and they shared a common traffic advisory frequency (CTAF).
When ZTA was north-west of Serpentine aerodrome and tracking south, the instructor broadcast that they were 10 NM from Serpentine at 2,500 ft and intended to pass abeam the aerodrome tracking south.
At about that time, a Morgan Cheetah aircraft, registered 19-5456 (5456), departed Serpentine for a private flight to Rottnest Island with a pilot and one passenger on board. The pilot reported that they made the following broadcasts on the CTAF: taxiing at Serpentine for runway 23; entering and rolling on runway 23 for a departure to Rottnest Island; and when departing overhead the aerodrome at 1,500 ft climbing to 3,000 ft heading to Rottnest via Carnac.
The pilot then changed the aircraft’s only VHF radio from the CTAF to the area frequency about 5 NM from Serpentine. The aircraft was then climbing through about 2,800 ft and tracking north-west when the pilot sighted an aircraft (ZTA) about 10–15 ft above, on a reciprocal track and about 100 m away. The pilot of 5456 immediately turned left and descended.
The student of ZTA sighted an aircraft (5456) in close proximity and alerted the instructor. The instructor saw 5456 making a steep left turn at about the same height as ZTA, took control of the aircraft from the student, and conducted a left turn to increase separation between the two aircraft. The aircraft passed at the same level and about 20 to 30 m horizontally from each other.
A search for other traffic is eight times more effective when a radio is used in combination with a visual lookout than when no radio is used. In areas outside controlled airspace, it is the pilot’s responsibility to maintain separation with other aircraft. For this, it is important that pilots use both alerted and un-alerted see-and-avoid principles.
On 15 April 2016, an instructor and student of a Grob G115C2 aircraft, registered VH-ZTA (ZTA), were conducting a local training flight in the training area south of Jandakot Airport, Western Australia. The training area was marked as a danger area[1] on the Perth Visual Terminal Chart (Figure 1). It was the student’s first flight in the training area, and the instructor was briefing the student and identifying landmarks including the two aerodromes situated in the training area – Serpentine and Murray Field. The two aerodromes shared a common traffic advisory frequency (CTAF), and the instructor advised the student to broadcast on the CTAF stating the aircraft’s position and intentions when approaching 10 NM from either aerodrome, again when at 5 NM and also overhead.
When ZTA was north-west of Serpentine aerodrome and tracking south, the instructor broadcast that they were 10 NM from Serpentine at 2,500 ft and intended to pass abeam the aerodrome tracking south. The instructor then heard the pilot of another aircraft broadcast that they were departing Murray Field tracking north at 3,000 ft, and another pilot broadcast that they were near Serpentine conducting airwork. The instructor again broadcast ZTA’s position and their intentions, while looking for the aircraft that was departing Murray Field and on a reciprocal track. The instructor did not sight the aircraft.
At about that time, a Morgan Cheetah aircraft, registered 19-5456 (5456), departed Serpentine for a private flight to Rottnest Island with a pilot and one passenger on board. The pilot reported that they made the following broadcasts on the CTAF: taxiing at Serpentine for runway 23; entering and rolling on runway 23 for a departure to Rottnest Island; and when departing overhead the aerodrome at 1,500 ft climbing to 3,000 ft heading to Rottnest via Carnac.
The pilot then changed the aircraft’s only VHF radio from the CTAF to the area frequency about 5 NM out from Serpentine. The aircraft was then climbing through about 2,800 ft and tracking north-west when the pilot sighted an aircraft (ZTA) about 10–15 ft above, on a reciprocal track and about 100 m away. The pilot of 5456 immediately turned left and descended.
The student pilot of ZTA sighted an aircraft (5456) in close proximity and alerted the instructor. The instructor saw 5456 making a steep left turn at about the same height as ZTA, took control of the aircraft from the student, and also conducted a left turn to increase separation between the two aircraft. The aircraft passed at the same level and about 20 to 30 m horizontally from each other.
The pilot of 5456 then contacted air traffic control, advised that they had just had a ‘close call’ with another aircraft and requested any traffic in the area. The air traffic controller responded that they could not verify 5456’s position or altitude as it was not equipped with a transponder.
Pilot comments
Instructor of VH-ZTA
The instructor reported that they did not hear any departure call from 5456 on the CTAF. Where possible, ATC will issue safety alerts when they identify the threat of a near collision in the training area. However, as 5456 was not fitted with a transponder, its height and accurate position could not be verified.
– Operations in the vicinity of non-controlled aerodromes, stated that an aircraft is ‘in the vicinity of a non-controlled aerodrome if it is within airspace other than controlled airspace;
a horizontal distance of 10 NM from the aerodrome (reference point); and
a height above the aerodrome (reference point) that could result in conflict with operations at the aerodrome.’
The CAAP further stated that when departing or arriving at non-controlled aerodromes, pilots should monitor their radios and broadcast their intentions as necessary on the published frequency.
Safety message
A search for other traffic is eight times more effective when a radio is used in combination with a visual lookout than when no radio is used. In areas outside controlled airspace, it is the pilot’s responsibility to maintain separation with other aircraft. For this, it is important that pilots use both alerted and un-alerted see-and-avoid principles.
Pilots are encouraged to ‘err on the side of caution’ when considering when to make broadcasts and whether specific frequencies should be monitored, particularly noting the fundamental importance of communication in the effective application of the principles of see-and-avoid. The ATSB report Limitations of the See-and-Avoid Principle outlines the major factors that limit the effectiveness of un-alerted see-and-avoid.
Insufficient communication between pilots operating in the same area is the most common cause of safety incidents near non-controlled aerodromes. CASA publication
provides advice in relation to making radio broadcasts to reduce the risk of coming in close proximity with other aircraft.
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
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 15 April 2016, the instructor and student of a Pacific Aerospace CT/4B aircraft, registered VH-YCO (YCO), conducted a dual (military) training flight under the instrument flight rules.[1] The aircraft departed from Tamworth Airport, and tracked to Narrabri Airport, before commencing the area navigation (RNAV) runway 11 approach to Gunnedah Airport, all in New South Wales.
Prior to commencing the approach, the instructor of YCO contacted the military radar controller (see Military radar control), who advised that they were not aware of any other aircraft in the area. The instructor reported that they broadcast on the Gunnedah common traffic advisory frequency (CTAF), when 18 NM from the aerodrome, advising that they were going to conduct the RNAV runway 11 approach, and stating their estimated time at the airport (Figure 1). The crew reported hearing a voice-back response from the aerodrome frequency response unit,[2] indicating that no one else had transmitted on the CTAF in the previous 5 minutes, and no response from any other aircraft on the CTAF.
At that time, an instructor and student pilot of a Piper PA-28-181 aircraft, registered VH-WJZ (WJZ), were conducting a local dual training flight from Gunnedah Airport. The instructor reported that they were broadcasting on and monitoring the CTAF.
At about 1450 Eastern Standard Time (EST), YCO was 13 NM north-west of Gunnedah on the RNAV approach for runway 11, and at 4,500 ft above mean sea level (AMSL), when they were alerted by the aircraft’s traffic collision avoidance device[3] of another aircraft. The device indicated that the other aircraft was 200 ft below them and 2 NM away. The instructor looked south and within 20 seconds sighted WJZ at the same level. The instructor took control of the aircraft from the student, and conducted a 60° angle of bank turn to the left to avoid WJZ.
The instructor of WJZ sighted YCO when about 13 NM north-west of Gunnedah aerodrome at about 4,000 ft AMSL. YCO was then to their north in their 2 o’clock[4] position. The instructor of WJZ conducted a left turn and reported sighting YCO commence a left. The aircraft passed at the same level about 150 to 200 m horizontally apart.
The instructors of the two aircraft subsequently communicated on the CTAF. The instructor of WJZ reported that they had not heard any relevant calls on the CTAF leading up to the incident.
Figure 1: Recorded track of VH-YCO, approximate track of VH-WJZ, and approximate location of near collision
Source: Instructor of VH-YCO – annotated by ATSB
Military radar control
The ADF established and operated a radar system in the vicinity of Tamworth to provide directed traffic information (DTI) to pilots operating CT4B aircraft in the Tamworth training areas. This was an interim measure to treat the risk of separation breakdown in the Tamworth training areas while those training areas and associated procedures underwent redesign and other systems were established. The DTI was provided on a discrete frequency monitored only by ADF aircraft. Directed traffic information was an advisory only service and controllers did not provide control or direction to pilots, but gave information aimed at increasing their situational awareness.
The military controller did not report any conflicting traffic before or during the incident.
Traffic collision avoidance device
YCO was fitted with a traffic collision avoidance device (TCAD), which warns of the presence of threat aircraft if the other aircraft is fitted with a functioning transponder that is being interrogated by a radar transmitter. The TCAD detects Secondary Surveillance Radar (SSR) transponders in aircraft within a certain proximity.
The TCAD displays threats detected within a predetermined volume of airspace known as a shield. The shield setting for the TCAD during the incident flight was +/- 1,000 ft in altitude and 2 NM. When a detected aircraft enters the pre-set shield, the pilot is alerted via aural and visual indications.
The TCAD system will not detect a threat aircraft that is not equipped with a transponder, the transponder is inoperative, or the transponder is operating but not being interrogated by either an SSR or a TCAS fitted aircraft. The TCAD is designed as an aid to situational awareness and should not be relied on for traffic separation.
In this incident, the TCAD identified WJZ as a threat and alerted the pilots of YCO.
Pilot comments
Instructor of VH-WJZ
The instructor of WJZ commented that the other aircraft was conducting military training and they have a radar in the Gunnedah training area, to provide them with traffic warnings. The military radar service did not identify any conflicting traffic, however, YCO’s TCAD identified WJZ, which indicated that WJZ’s transponder was functioning.
The instructor reported that there was some distortion in the broadcasts from YCO heard after the incident.[5]
The instructor further commented that in future, they would broadcast their position in the training area every 15 minutes; even if there were no broadcasts to indicate there may be nearby aircraft.
Instructor of VH-YCO
The instructor of YCO commented that if pilots of aircraft conducting instrument approaches broadcast their aircraft’s position with reference to a compass, this may assist visual flight rules’ pilots to assess whether there could be a conflict.
Safety action
Whether or not the ATSB identifies safety issues in the course of an investigation, relevant organisations may initiate safety action in order to reduce their safety risk. The ATSB has been advised of the following safety action in response to this occurrence.
Operator of VH-WJZ
As a result of this occurrence, the operator of VH-WJZ has advised the ATSB that they are taking the following safety actions:
Airspace procedure
As the instrument approach lies within the Gunnedah training area, student pilots are required to remain below 3,000 ft when within 5° of the approach path. Additional risk assessments were conducted at the other company flying school locations and a similar hazard was found at Scone, where similar de-conflicting provisions have been made.
Safety message
The ATSB report Limitations of the See-and-Avoid Principle outlines the major factors that limit the effectiveness of un-alerted see-and-avoid. In this occurrence, un-alerted see-and-avoid did lead to the instructor of one aircraft sighting the other. However, insufficient communication between pilots operating in the same area is the most common cause of safety incidents outside controlled airspace and near non-controlled aerodromes. A broadcast that does not provide a clear understanding of the location of an aircraft, or the intentions of the pilot, is often ineffective in directing other pilots where to focus their lookout.
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
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 13 April 2016, an instructor and student of a Jabiru J170-D aeroplane, registered 24-7750 (7750), conducted a local training flight from Bathurst Airport, New South Wales. At about 1442 Eastern Standard Time (EST), as they were returning to Bathurst, the instructor broadcast on the Bathurst common traffic advisory frequency (CTAF) that they were inbound from the south-west, and added that they were estimating arrival in the circuit at 1446. As they subsequently arrived in the circuit, the instructor broadcast that they were joining the circuit on an early downwind for runway 17, for a full-stop landing.
The wind was from the east-south-east. Powered aircraft were operating on runway 17 and gliders (and towing aircraft) were operating on runway 08. Bathurst aerodrome elevation is 2,435 ft above mean sea level (AMSL) (Figure 1).
About a minute after broadcasting their arrival in the circuit, the pilot of 7750 asked Glider Ground[1] how many gliders were in the air. Glider Ground advised that there were ‘two gliders, NGH and NDQ, just thermalling,[2] at 4,000 ft off the threshold of runway 26.’ The pilot of 7750 confirmed sighting two gliders.
Meanwhile, a student pilot of a Glaser-Dirks DG-1000S glider, registered VH-NDQ (NDQ) was conducting a solo flight at Bathurst. The student had been briefed prior to the flight to make a downwind call, stay close to the runway in use by the gliders, and to keep a good lookout. At about 1449, about 90 seconds after the pilot of 7750 had communicated with Glider Ground regarding glider traffic in the air, the pilot of NDQ broadcast on the Bathurst CTAF that they were on left downwind for runway 08.
Immediately following the downwind call by the pilot of NDQ, the pilot of 7750 broadcast that they were on left base for runway 17, and soon after, broadcast that they were on final approach to runway 17 for a full stop landing. The pilot of NDQ reported hearing both those broadcasts, but did not make any broadcasts or directed radio calls in response.
After 7750 touched down on runway 17, about 100 m before the intersection with runway 08, the pilot sighted a glider (NDQ) on short final for runway 08, at an estimated 100 ft above ground level. The pilot assessed that they did not have sufficient time to stop before the intersection of runway 08, so applied full power to cross runway 08 as quickly as possible.
When at about 500 ft above ground level and on final approach to runway 08, the pilot of NDQ sighted 7750 their 10 o’clock[3] position at about the same altitude. As 7750 landed, the pilot of NDQ assessed that there was the potential for a collision, closed the glider’s airbrakes[4] and initiated a climb to pass over 7750. As the glider passed over 7750 near the intersection of the two runways, the pilot of NDQ heard the aircraft’s engine increase power. The glider then landed ahead on runway 08 (Figure 1).
The instructor in 7750 lost sight of NDQ as it passed overhead. As 7750 accelerated with a high power setting, the instructor elected to continue the take-off. The pilot of 7750 then conducted a circuit before landing safely.
Figure 1: Layout of Bathurst aerodrome showing indicative tracks of 7750 and NDQ
Source: Airservices Australia – annotated by ATSB
Pilot comments - Pilot of 24-7750
The pilot of 7750 commented that the circuit was very busy at the time of the incident. They were maintaining a good lookout and listening intently to the CTAF for positional information from the gliders, noting that gliders would have ‘right of way’ over powered aircraft. During final approach to runway 17, the instructor was communicating with the student in 7750 for teaching purposes.
The pilot also commented that they now discuss operational intentions with the glider operator at the commencement of each day’s operations.
Safety message
Simultaneous operations on crossing runways can be problematic, particularly where the volume of traffic is high and where the nature of the potentially conflicting operations are dissimilar (such as powered flight and gliding operations). Organisations responsible for the coordination and conduct of such activities are encouraged to carefully assess and manage the risks involved. This is particularly important when operations are likely to involve instructional flights and relatively inexperienced pilots, where workload and the potential for pilot distraction may be elevated.
This incident highlights the importance of effective communication. The primary purpose of communications on the CTAF is to ensure the maintenance of appropriate separation through mutual understanding by pilots of each other’s position and intentions. Where a pilot identifies a risk of collision, that pilot should alert others as soon as possible to allow a coordinated and effective response.
stated that ‘whenever pilots determine that there is a potential for traffic conflict, they should make radio broadcasts as necessary to avoid the risk of a collision’.
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
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 6 April 2016, Pacific National (PN) grain train 5422N parted at Parkville on the Main North Line. A fractured yoke on the trailing end of the fifth wagon allowed the yoke pin to fall out and the coupler shank to disengage from the wagon. The coupler shank fell into the four foot of the track and damaged the underbelly discharge doors on 10 wagons as the train progressed over the coupler. Approximately 10 tonnes of barley was released from the wagons as a result. The trailing wheelset on the thirteenth wagon was derailed, then ran in a derailed state for approximately 45 metres causing damage to several track sleepers before the train came to a stop. Regular services were able to continue under caution past the incident site via the adjacent crossing loop. Wagon recovery and track repairs was completed without any further incident.
What the ATSB found
A draftgear component (the yoke), that was not compliant with a PN maintenance standard, was not identified during a maintenance inspection and re-entered service undetected. The yoke was an earlier design and susceptible to fatigue failure. PN had identified the issue and completed a programme to replace this yoke design across their grain wagon fleet however, the yoke on this wagon had been overlooked.
What's been done as a result
PN issued an additional Rolling Stock Notice to their maintenance teams to advise of the incident and to mandate that all yokes in the grain wagon fleet were checked to ensure no yoke of this design remained in service.
Safety message
Maintenance systems must ensure that when a non-compliant component is identified as needing replacement, all such units are located and replaced.
Figure 1: 5422N at Parkville
Source: ATSB
Safety issues and actions
Whether or not the ATSB identifies safety issues in the course of an investigation, relevant organisations may proactively initiate safety actions in order to reduce their safety risk. The ATSB has been advised of the following safety actions in response to this occurrence.
The presence of the earlier design of yoke on wagon NGKF 35898X was not detected during preventative maintenance activities.
The occurrence
At 0230 on 6 April 2016 PN grain train 5422N parted at Parkville (approximately 322.350 km[1]) on the Main North Line, Hunter Valley, NSW. The train parted due to a fractured yoke (in the draw gear assembly) on the trailing end of the fifth wagon (NGKF 35898X). The crew of 5422N comprised of a driver and second person.
The fractured yoke allowed the yoke pin to fall out and the coupler shank to disengage from the wagon. The coupler shank fell into the four foot of the track and damaged the underbelly discharge doors on 10 wagons as the train progressed over the coupler. Approximately 10 tonne of barley was released from the wagons as a result.
The trailing wheelset on the thirteenth wagon was derailed when the fallen coupler struck the wagon’s fourth axle. The wheelset ran in a derailed state for approximately 45 metres before both parts of the train came to a stop. A number of track sleepers were damaged during the incident.
The driver notified the Network Control Officer Upper Hunter 2 (NCO) that 5422N was stopped approximately 80 m from signal 06-12M. The driver told the NCO, he had experienced a sudden loss of air from the train which led him to believe the train had parted.
The second person conducted a walking inspection of the train and radioed the driver that the train had parted behind the sixth wagon and he could not see the remainder of the train.
The driver advised the NCO that an adjacent train in the Parkville crossing loop was not to move as he could not confirm the location of his detached train. The NCO told the driver of 5422N that he would warn the other train of the incident. The NCO also advised the driver that based on his indicator board, the two portions of the train were between the two yard signals and the line was clear for the other train to come out of the crossing loop.
With that knowledge, the NCO cleared the signal for the other train to depart from Parkville crossing loop. The second person continued his inspection and found the detached portion of 5422N and the flashing tail light marker[2] on the final wagon, confirming the train was clear of the yard signals.
The driver asked the NCO for confirmation of track protection for 5422N. The NCO confirmed that protection of the train was being provided by the yard signals being blocked[3].
The second person secured the detached portion of 5422N by applying the handbrakes on all wagons. The driver secured the locomotives and the front wagons of the train.
At approximately 0400 the NCO informed the driver that a Condition Affecting the Network (CAN) had been issued.
The driver and second person were post incident drug and alcohol tested and ceased duties for the rest of their shift in accordance with PN procedures. Both crew members returned a negative result from the post incident testing.
Site clean up started at approximately 1500. PN arranged for the damaged wagons and the spilled barley to be cleared from the site. PN then shunted the two portions of 5422N and re-railed the derailed wagon.
At 0210 on 7 April 2016 Australian Rail Track Corporation (ARTC) track maintainers were able to commence emergency track repairs and were completed by 0600. In accordance with ARTC procedures, a temporary speed restriction of 40 km/h was placed on the main line through Parkville to allow operations to continue.
From the evidence available, the following findings are made with respect to the derailment of grain train 5422N at Parkville, NSW on 6 April 2016. These findings should not be read as apportioning blame or liability to any particular organisation or individual.
Contributing factors
The yoke was an earlier design prone to failure through fatigue cracking.
The presence of the earlier design of yoke on wagon NGKF 35898X was not detected during preventative maintenance activities.
Other factors that increased risk
Nil
Safety analysis
The ATSB found that a draftgear component (an older design yoke), that was not compliant with a Pacific National (PN) maintenance standard, and not identified during a periodical wagon maintenance inspection and the yoke re-entered service undetected.
PN had a system in place to remove this early design yoke from their grain wagon fleet and replace it with a later design yoke better suited to the application. However, this yoke had been overlooked by the wagon maintainers and consequently continued in service up until its failure on 6 April 2016.
The yoke fitted on the rear of the fifth wagon, NGKF 35898X, was of an early design and was known to be susceptible to fatigue failure. The undetected older style yoke eventually failed in-service and led to the train parting and the subsequent derailment (see Figure 10).
While the train data logger information indicated that some brake applications on 5422N did not comply with PN procedures, ATSB concluded train handling did not contribute to the incident. After the yoke pin fell out of the assembly, the downhill operation most likely kept the two portions of the train together until the train negotiated a slight uphill gradient at Parkville. Here the train experienced a longitudinal tensile load that allowed the two portions of the train to separate.
The track leading to the incident site was inspected by a track specialist on behalf of PN. It was concluded there were no track defects or anomalies that could have contributed to the incident.
Figure 10: Event sequence
Source: ATSB
Yoke failure
The yoke from wagon NGKF 35898X had a manufacture date stamp ‘10/71’. NGKF wagons were manufactured in 1976. The yoke was approximately five years older than the wagon itself. It was therefore, likely that this yoke was the original yoke fitted to this wagon.
The yoke design had recently been identified by PN as having a finite life due to a propensity to fatigue failure. The tensile strength of the parent metal and the lack of internal rounded relief fillets in high stress areas of the yoke contributed to this issue.
The yoke had fractured at the rear section where the top and bottom longitudinal straps connected with the backing face (see Figure 11).
Figure 11: Fractured yoke
Source: Bureau Veritas, annotated by ATSB
PN commissioned Bureau Veritas (BV) to conduct a metallurgical examination to identify the nature of yoke’s failure mechanism. The examination identified that the yoke had failed due to fatigue cracking which had initiated at multiple points on the inner face of the top yoke strap (see Figure 12). Fatigue cracking had progressed through approximately 85 per cent of the material’s cross-section before the ductile failure of the remaining material. The bottom yoke strap subsequently failed with approximately 10 per cent of the material’s cross-section subject to fatigue cracking before the ductile fracture, failing after the top arm failed.
The BV report stated that:
‘it was suspected that the fracture may be due to a material with low toughness properties[6] being in service for a long time, which was exposed to cyclic stress.’
The BV metallurgical examination focussed on the material properties and while it did not review the design of the component, the report did note that “stresses are concentrated at the critical regions (e.g. radius relief groove, curves, thickness change)”.
Figure 12: Fracture faces of yoke
Source: Bureau Veritas including annotation
Fatigue cracking in yokes
Other research has been conducted into fatigue cracking and stresses in yokes in heavy haul services[7]. Cookson et al 2013, identified a propensity for fatigue cracking in yokes due to the vertical oriented bending of the draft system. This vertical oriented bending in yokes was considered most likely due to misalignment in the draft system. As such, identifying misalignment in the draft system was considered important as it could affect the overall service life of the yoke.
It was noted that PN’s Wagon Maintenance Manual (WMM) 07-02_09 (dated 7 May 2009) Couplers and Draft Gear Maintenance makes reference to checks for alignment when inspecting varous parts of the draft system, including; the knuckle, coupler shank, the yoke strap and drawgear carriers.
Wagon maintenance
The periodic maintenance program in place for PN’s grain wagons was developed to ensure reliable and safe operation of the wagons.
WMM 07-02_09 sets out the maintenance requirements for wagon couplers and draft gear. Section 1.9 deals with yokes and it includes the following:
Yoke straps are to be inspected for cracking
Where video/borescopes are available these shall be used to detect cracking in yoke straps.
If cracking is found (in the internal radius locations) the yoke shall be scrapped
Further, Section 1.9.4 makes specific reference to earlier design yoke straps:
‘Wagons manufactured before 1980 used lower grade steel in the draft gear castings and do not have a relief fillet in the rear top and bottom inside corners as identified in the picture below (see Figure 13) (i.e. sharp radius). Replace these when found.’
Additionally, while wagons with a draft capacity of less than 1.3 MN were excluded from this last requirement, NGKF 35898X had a draft capacity of 1.8 MN.
These requirements specified in PN’s WMM suggests the yoke on wagon NGKF 35898X should have been identified and replaced at the last maintenance intervention.
Figure 13: Yoke inspection areas
Source: PN WMM 07-02
It is worth noting the task requirements on wagon maintainers when required to inspect a unit train consist[8]. When a unit train consist is scheduled for maintenance, such as the B inspection[9], the consist is scheduled into a maintenance centre for usually 24 hours before being scheduled onto its next service.
In this time the wagon maintainer would need to attend to a list of items and either, test, service or lubricate, replace, adjust, gauge, measure or inspect each of these items on each wagon (for grain unit train consists, 40 wagons). The list of items to attend to on the B inspection sheet is 92 items.
Additionally, the location of the yoke in situ makes it challenging for the wagon maintainer to identify cracking in the yoke. As pictured in Figure 14, the wagon maintainer is required to inspect the highlighted areas. As Figure 15 shows, the access to view these areas while the yoke is in situ is difficult and potentially restricted by time constraints in the maintenance opportunity.
Figure 14: Yoke inspection areas
Source: PN WMM 07-02
Figure 15: Yoke in situ
Source: ATSB
Train handling
The yoke pin was found nearly 6 km before Parkville. There was a constant falling grade towards Parkville and the train driver was using dynamic braking to control train speed. Therefore, the wagons of the train generally remained in a compressed state ensuring the train did not part.
On account from the driver, there is a slight incline after Wingen just prior to the downhill into Parkville. At this point the driver allowed the train to roll freely through the section of track to maintain speed. This coincides with a releasing of the buffering or compressive forces in the draw gear. The yoke pin most likely fell from the train at this point which is where it was found during inspection post incident (see Figure 16).
The train was able to continue without a mechanical connection through to Parkville as compressive forces kept the train and brake air hoses together on the downhill into Parkville. However, as the train rolled into Parkville at approximately 60 km/hr, the driver reduced dynamic braking to account for the slight incline to the middle of the yard which is when the train parted, seperating the air hoses. This enabled the brakepipe to vent to atmosphere, triggering an emergency brake application which brought both parts of the train to a stop.
The train handling in the lead-up to the incident was not considered a contributing factor to the incident.
Figure 16: Yoke pin lying in the four foot
Source: ARTC including annotation
Previous incidents
PN reported that, over the five years preceding the incident, there were 14 incidents of trains parting due to defective yokes. These incidents occurred between 2011 and 2016. There were a further 13 wagons that had their yokes replaced during maintenance between 2011 and 2012. No older style yokes were detected after that date until this incident in 2016.
Pacific National investigation
PN conducted a safety investigation into the incident at Parkville. PN’s internal Investigation Report (Form PN-FOR-SAF) dated 10 May 2016 identified that the incident wagon (NGKF35898X)
‘underwent regular maintenance and inspection as per WMM 01-01b_05 Bulk Services Division Services Schedule of Inspections; however, the early model yoke strap on this wagon was not identified or replaced (as per WMM 07-02_09).’
Two of the preventative actions in the report were:
To develop and issue a Rolling Stock Notice (RSN) to all wagon maintenance and engineering teams to reiterate required inspections on early model yokes on wagons and replacement of specified parts.
Develop a safety alert detailing the contributing factors for derailment and distribute to NSW/Vic operations.
ATSB requested PN to demonstrate that the actions had been completed. PN notified the ATSB that the first two items had been closed out by issuing a single RSN (see Appendix A) to wagon maintainers.
Appendix A – Pacific National Rolling Stock Notice
Sources and submissions
Sources of information
The sources of information during the investigation included:
The Australian Rail Track Corporation Ltd.
Office of the National Rail Safety Regulator
Pacific National
Submissions
Nil
Context
Incident location
Parkville is located between Scone to the south and Murrurundi to the northwest (see Figure 2). Train 5422N was travelling from Werris Creek to Carrington Grain Terminal near Newcastle on the Main North Line. The incident occurred adjacent to the township of Parkville in the Upper Hunter region of NSW.
Figure 2: Incident location map
Source: Geoscience Australia, annotated by ATSB
Rail infrastructure information
There are two tracks at Parkville, namely a main line and a crossing loop. A single, bidirectional line connects Parkville and Murulla to the north. The track from Murulla to Parkville is predominantly on a falling grade or downhill (see figure 3). Murulla sits between Murrurundi and Parkville at approximately 339.4 km.
Figure 3: Curve and Gradient diagram of track between Murulla and Parkville
Source: ARTC, annotated by ATSB
Safeworking system
The safeworking system in place was Centralised Traffic Control (CTC). In this system, lineside signals and associated track circuits allow the NCO, from the control centre at Broadmeadow, see the location of any given train operating along the Main North Line.
Train information
5422N was a loaded grain train consisting of 40 wagons and hauled by three locomotives. It was approximately 636 m long with a mass of 3040 tonne excluding the locomotives. It was typical of many grain trains working throughout NSW.
The yoke and draw gear assembly
The yoke is an integral component of a wagon’s draw gear assembly. While a number of different designs are in service, they are all designed to retard the train’s longitudinal draft and buffering[4] forces. The major components of a draw gear assembly are typically: coupler shank, buffer package, yoke and yoke pin (see Figure 4).
The yoke houses the buffer and is connected to the coupler by a pin or key (in this case a pin). The yoke is a part of the draw gear and transmits draft and buffering forces between wagons. Under compression, the force is transferred between the back-strap of the yoke and the wagon. In operation, the back-strap is subjected to repetitive loads. To mitigate against this effect, later yoke designs (post-1980) have internal rounded smooth radius fillets at high stress locations which are better able to withstand the cyclic stresses that are imposed on these areas. The later yokes are manufactured from a higher tensile steel.
The yoke in this incident was a pre-1980 design made from a lower tensile steel and without rounded smooth radius fillets in the high stress locations.
PN has maintenance systems in place to manage it’s total wagon fleet of approximately 15,000[5] wagons, across several locations in Australia.
PN was aware that the early design yokes (in grain wagons manufactured before 1980) needed to be removed from their fleet and replaced with later design yokes made from higher tensile steel and with internal rounded smooth radius fillets.
As such, specific instructions in PN’s Wagon Maintenance Manual (WMM) had been developed to provide instruction to PN’s wagon maintainers to identify and change out the early-design yokes as the wagons came in for preventative maintenance.
Site observations
ATSB observed the train had parted five wagons behind the locomotive (see Figure 1). The draw gear assembly was missing from the rear of the fifth wagon, NGKF 35898X (see Figure 5). The coupler shank was found under the rear axle of the rear bogie of the sixteenth wagon, NGKF 35864R (see Figure 6).
Figure 5: Location for draw gear assembly
Source: ATSB
Figure 6: Coupler shank in four foot
Source: ATSB
The bottom discharge doors on 10 wagons had been damaged. Approximately 10 tonne of barley had spilled from the wagons (see Figure 7).
Figure 7: Wagon doors and spilled grain
Source: ATSB
The coupler shank struck the axle of the trailing wheelset on the thirteenth wagon, NGPF 36032J. This resulted in the wheelset derailing near the crossing loop (see Figure 8). The wheelset travelled in a derailed state for approximately 45 m, damaging a number of concrete sleepers, before coming to a stop. (see Figure 9).
Purpose of safety investigations & publishing information
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
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 4 April 2016 at approximately 0505 Australian Eastern Time (EST),[1] lead locomotive NR8 on train 7YN2 caught fire near the southern side of Cardiff railway station, New South Wales (NSW). The crew stopped the train 250 metres north of Cardiff station after they were alerted to the fire by flames emanating from the locomotive’s engine cab. The crew informed Network Control[2] they could not contain the fire and requested the assistance from NSW Fire and Rescue (NSWFR). At 0510, the crew applied the locomotive park brake and both crew members evacuated without injury. The crew further secured the train by applying the hand brakes on the first 10 wagons and isolated the other two locomotives. NSWFR attended at 0525 but could not commence extinguishing the fire due to the overhead electrical wiring remaining energised. At 0535 an engine explosion displaced a number of engine crank case inspection covers. At 0543 passenger service N116 was stopped from passing the burning locomotive and passengers were detrained to alternative transport. At 0635 the overhead wiring was de-energised and by 0830 NSWFR had extinguished the fire.
The ATSB found that two of the 10 oil filter tank cover bolts had failed beneath the retaining nut due to fatigue and overload fractures. There was evidence of fretting damage on the tank cover at the failed bolt positions. This was consistent with a loose bolted joint associated with in service movement of the assembly. The fire ignited when the displaced tank cover enabled high pressure oil to escape and come in contact with hot engine components (Figure 1).
Figure 1: Fire in lead locomotive NR8 passing through Cardiff Station
Source: Sydney Trains CCTV
The oil filter tank is a part of the locomotive engine’s lubricating oil system (Figure 2 and 3). The lubricating oil system capacity is approximately 1500 l. There was approximately 800 l of lubricating oil left in the system after the incident.
Figure 2: Schematic of engine oil lubricating system
Source: GE annotated by ATSB
Figure 3: NR8 engine removed from bay (L) and oil filter tank in situ (R)
Source: ATSB
Safety analysis
Fires can be unique in their ignition and progress, however, organisations need to prepare their staff to deal with the early stages of the fire so they can minimise escalation of the fire.
Failed components
An independent metallurgist established that the 19 mm diameter oil filter cover bolts (Figure 4) had suffered unidirectional fatigue failure through the root diameter of the thread. The fractures occurred directly below the nut adjacent to the cover’s nut seat. The nut seat exhibited fretting damage, which suggested there was movement across the bolted joint and most likely attributed to excessive torqueing of the bolts.
Figure 4: NR8 oil filter tank and cover
Source: ALS annotated by ATSB
The fracture surfaces of the broken bolts suggested the bolts had been moving transversely to the plane of the cover causing micro fractures at the root of the thread adjacent to the nut seat. Each movement of the bolt would have increased the size of the fatigue fractures and progressively reduce the bolt’s tensile strength.
Bolt eight exhibited a small central region ductile fracture surrounded by fatigue fractures emanating from the root of the thread. Bolt nine had a larger ductile fracture surrounded by a smaller area of fatigue fractures. The central region ductile fractures corresponded with the final failure of the bolts (Figure 5 and 6).
The area of the ductile fracture on bolt number eight was smaller than on bolt number nine suggesting bolt eight had fatigued more and failed first. Bolt nine most likely failed after bolt eight.
Figure 5: Bolt number 8 (Top) and 9 (Bottom) with cross sections
Source: ALS annotated by ATSB
Evaluation of the other eight bolts indicated similar fatigue fracturing in similar locations.
There was four engine crank case inspection covers displaced during the occurrence. This was likely due to a secondary fire and subsequent minor explosion in the crankcase.
Postfire response
The crew had on board one 4.5 kg fire extinguisher located in the cab of the locomotive and two larger 9 kg fire extinguishers located in the radiator compartment. All fire extinguishers were dry powder suitable for fuel, oil and electrical fires.
When the driver noticed the fire he immediately applied the emergency shutdown of the locomotives and called train control. Whilst on the radio to train control he made an assessment of the fire to determine if he was able to put it out but confirmed NSWFR would be needed. The driver then applied the park brake before exiting the locomotive with the second person and stood in a safe place away from the burning locomotive.
Approximately 15 minutes later NSWFR arrived at the nearby overhead bridge (Newcastle Street). Whilst the driver discussed the situation with NSWFR the second person applied hand brakes to 10 wagons to ensure the train was stabilized. The driver and second person then isolated the remaining two locomotives (NR90 and NR103). NSWFR commenced set up but could not start due to the live overhead lines.
The isolation of the overhead lines was confirmed at 0548 approximately 23 minutes after notification. It took a further 47 minutes before residual current was confirmed out of the overhead lines. NSWFR then commenced putting out the locomotive fire. All parties had ensured they could approach the burning locomotive only when it was safe to do so.
Network Control informed scheduled passenger service N116 of the locomotive fire at Cardiff at 0531 he informed the driver to approach at caution and provide advice on the situation on arrival. At 0543 N116 was on approach to the incident site when the site incident commander stopped the train and informed the driver of N116 that the train would need to be detrained as passing the site was not possible at that stage.
Findings
These findings should not be read as apportioning blame or liability to any particular organisation or individual.
Oil filter cover retaining bolts eight and nine had failed through the first thread beneath the nut by a unidirectional fatigue failure mechanism.
The pattern of fretting damage on the cover nut seat suggested relative movement was evident between bolts eight and nine and the oil filter cover.
Safety action
In response to the retaining bolt failures, Pacific National has advised the ATSB that they have completed the following actions:
Developed and implemented a bolt tightening and removal procedure
Reduced the bolt replacement frequency from 732 days to 366 days
Retrofitted a guard in NR locomotives to minimise the risk of oil escaping from the filter tank and contacting hot engine components.
Other finding
The postfire response from all parties was managed in accordance with procedures.
Safety message
Correct tensioning of bolts can be a critical aspect of ensuring equipment functions as designed. Operators should ensure their safety management systems provide appropriate procedures for bolt inspection and tensioning where there is a risk of equipment failure, especially when the consequence can escalate to fire.
The ATSB SafetyWatch highlights the broad safety concerns that come out of our investigation findings and from the occurrence data reported to us by industry.
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
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.
