A train collision, resulting in the derailment of three wagons, highlights the importance of good communications in reducing the risk of collision.    

On 31 March 2015, freight train 2MP9 collided with the rear end of stationary freight train (2MP1) at Mile End, South Australia. The collision resulted in moderate track damage and the derailment of three wagons at the rear of train 2MP1. Fortunately, there were no injuries to train crews.

The accident occurred as train 2MP9 passed the southern end of the Mile End crossing loop. As it approached train 2MP1 under a ‘calling on/low speed’ signal, some stumpy vegetation and a low fence initially obscured the driver’s view of the empty flat wagons at the rear of the train. When the driver finally saw the rear of train 2MP1, he immediately made an emergency brake application, but was unable to stop the train before it collided with 2MP1.

While acknowledging the requirement under a ‘Proceed Restricted Authority’, for drivers to be able to stop their train within half of the distance that the line ahead is clear, the ATSB noted that the network control officer’s pathing of a train onto a line occupied by a preceding train (when an alternate route was available and not obstructed), had created an elevated level of risk. Similarly, well thought out and clear communications between the network control officer (NCO) and crew of the approaching train (as to the presence of another train on the line ahead) could have significantly enhanced the train crew’s situational awareness.

The Australian Rail Track Corporation (ARTC) and SCT Logistics have implemented a range of proactive strategies for enhancing the safe operation of train movements when entering an occupied section of track under a ‘Proceed restricted authority’ (PRA). This includes the use of all available infrastructure to reduce risk, encouraging communications between train drivers and NCOs where clarification of operational conditions is necessary, and a review of the National Train Communications System (NTCS) for the Adelaide area.

Safety message

Train drivers should carefully consider their obligations when accepting a ‘Calling on/Low speed’ signal indication in relation to sighting constraints, train speed and occupation of the track ahead. In circumstances where sighting constraints may exist, drivers should consider requesting further information from the NCO before moving through the track ahead.

When dispatching trains, NCOs should carefully consider the pathing of trains under their control and the communication of information that may mitigate collision risk. 

Read the final report: Collision between freight trains 2MP1 and 2MP9, Mile End, South Australia, on 31 March 2015

A fatal wirestrike accident involving a Cessna 182L graphically illustrates the dangers of unauthorised low-level flying.

On 20 July 2014, the aircraft struck wires from a high voltage powerline while the pilot was conducting a private flight at low altitude near the rural township of Burrumbuttock, NSW.

Witnesses saw the aircraft flying low towards the township before it struck wires above a paddock on the outskirts of the town. The aircraft then rolled and impacted terrain. The wreckage came to rest a short distance from the Farmers Inn. Tragically, the pilot died in the accident.

The ATSB found no evidence of any engine or airframe defect that may have contributed to the accident.

Importantly, the pilot did not hold any approval to conduct low flying and had not received training to identify hazards or operating techniques for flight close to the ground. The evidence also indicated that the pilot had a history of unauthorised low flying.

The pilot was reported to be in good health with no issues that might have affected his ability to fly an aircraft. Despite this, the postmortem medical examination revealed a pre-existing medical condition that could have resulted in pilot incapacitation.

While it is possible the pilot may have been incapacitated immediately before the accident, the aircraft was flown at a level that provided little margin for error if an event had been experienced.  

Safety message

This fatal accident provides a clear message to pilots: don’t fly low if you’re not authorised, or don’t have to.

Flying below the regulated thresholds of 1,000 feet AGL overpopulated areas and 500 feet over non-populated areas provides very little margin for error if something goes wrong. Pilots who fly below this height without appropriate training and an operational reason to do so are exposing themselves and any passengers to an increased risk of striking hazards, such as electrical power lines, many of which are difficult to see from the cockpit of an aircraft in flight. 

The failure of an air turbine starter led to the in-flight shutdown of the number one engine of a China Airlines Airbus A330 aircraft in October 2013. (An air turbine starter uses pressurised air to rotate the high-pressure rotor within the engine during the engine start sequence).

The incident occurred approximately four hours into a flight from Sydney to Taipei, Taiwan ROC. The flight crew completed a precautionary shutdown of the number one engine in response to a low oil pressure warning, and diverted the flight to Cairns, Queensland.

The ATSB investigation found that the air turbine starter had sustained an uncontained failure. When the starter failed, an oil scavenge pipe from the number one engine was severed by debris that had not been contained by the starter casing. This resulted in a rapid loss of oil that required the number one engine to be shutdown.

The investigation identified that the starter failure was due to the failure of the output shaft bearing. Damage to the bearing was consistent with exposure to transient loads from the crash engagement of the starter clutch during engine starts, or, from axial loads to the bearing from the horizontal driveshaft.

Safety actions taken

To eliminate the potential for crash engagements to occur during operation of the air turbine starter, the starter manufacturer was phasing out the single pawl and ratchet clutch mechanism. A redesigned air starter using a full range pawl and ratchet is being incorporated into service. The manufacturer has also initiated changes to limit the potential for axial loads to be applied to the output shaft bearing of the turbine stater.

The resulting changes in design will eliminate air turbine starter failures associated with crash engagements, though they will not completely eliminate the potential for failures to occur (contained or otherwise).

Other safety action from the starter manufacturer, the engine manufacturer, and the operator includes a number of changes to the procedures for oil level checks and changes.

The ATSB is satisfied that the likely reoccurrence of this failure mode will remain low as a result of these safety actions.

Read the final report: Engine shut down in-flight involving Airbus A330-302, B-18358, 887 km east-north-east of Darwin Airport, on 3 October 2013

A V/Line passenger train was brought to a grinding halt after it collided with maintenance equipment left behind from track work.

On 16 February 2015, track maintenance was being conducted at Montgomery (between Sale and Bairnsdale) in Victoria. To allow a passenger train to pass through the section, the maintenance gang cleared the track and lifted the track protection. When the gang vacated the line however, some equipment was left behind on the track. 

As the V/Line passenger train approached the work site, the driver saw the obstruction. Despite making an emergency brake application the driver was unable to bring the train to a stop before it collided with the equipment. The train remained on the track and there were no injuries to passengers or rail personnel.

The ATSB’s investigation found that the item of maintenance equipment struck had earlier been moved along the track - away from the immediate area of works. Subsequently, this equipment was overlooked when the track was cleared of workers and other tools.

The task of ensuring that the line was clear had cascaded to a third party within the maintenance gang. There was no formal system in place to manage this process of informal delegation.

As a result of this and other related safe working incidents, V/Line has advised that a review of infrastructure rules, safety procedures and training has been implemented.

Safety message

This incident highlights the need for track maintenance personnel to be particularly vigilant in ensuring that no obstructions remain on the line when authorising the passage of a train through a work site.

Similarly, network managers should ensure that systems and processes are in place to minimise the potential for maintenance equipment to be left on track. 

Read the final report: Passenger train collision with maintenance equipment, Montgomery, near Sale, Victoria, on 16 February 2015

A tragic ballooning accident in the Northern Territory shows how quickly clothing entanglement in industrial equipment can cause a fatality.

On 13 July 2013 a Kavanagh E‑260 balloon was being prepared for a charter tourist flight near Alice Springs, Northern Territory. Due to the wind conditions at the time, the passengers were pre-loaded into the balloon basket as it lay on its side. As one of the passengers prepared to enter the basket, their scarf became entangled in a fan that was being used to inflate the balloon envelope. Consequently, the passenger was rapidly drawn into contact with the fan’s steel guard and the scarf was pulled tightly around their neck. Despite being provided with first aid, and subsequent medical treatment, the passenger died as a result of their injuries several days later.

The ATSB found that pre-loading of the passengers during the inflation process, although appropriate in the wind conditions, resulted in them coming into close proximity to the operating inflation fan. Additionally, the mesh and steel tubing guard positioned around the inflation fan was ineffective in preventing loose items of clothing from becoming entangled in the wooden fan blades and driveshaft. As a result, when the passenger approached the balloon basket in preparation for loading, their scarf was drawn into the fan blades, leading to fatal injuries.

The pilot conducted two safety briefings prior to the proposed flight that advised the passengers to remain clear of the fan as it was noisy and dangerous. A warning sign fitted to the fan was also pointed out. However, none of the passengers recalled that the specific danger of fan entanglement had been mentioned.

Shortly after this accident, the ATSB forwarded a Safety Advisory Notice (SAN) to balloon operators highlighting the circumstances of this occurrence and advising that they review their risk controls in relation to the safety of inflation fans. With the assistance of the Professional Balloon Association of Australia and the Australian Ballooning Federation (ABF) the SAN was also provided to their members. The ABF and Northern Territory (NT) WorkSafe also issued safety alerts highlighting the danger of fan entanglement.

The balloon operator made a number of changes to prevent a similar accident, including:

• modification of all fan guards to reduce the likelihood of entanglement
• establishment of a passenger exclusion zone in the vicinity of the fan
• assignment of a crew member whose sole duty was to operate and supervise the fan
• inclusion of detail on the danger of entanglement in the passenger briefing card.

Safety message

This accident highlights how quickly entanglement in industrial equipment, such as the inflation fan, can cause fatal injury. While highlighting the danger to those unfamiliar can reduce the risk, isolating the hazard through effective fan safeguarding and passenger control is the most effective method of preventing such tragic accidents.

Read the final report: Flight preparation event involving Kavanagh Balloons E-260, VH-FSR, near Alice Springs Airport, Northern Territory, on 13 July 2013

An axle bearing failure on a train wagon contributed to the derailment of a freight train near Hugh River in the Northern Territory on 23 December 2014.

The wagon, carrying distillate fuel, remained upright and there was some minor damage to the track (sleepers and rail clips). Fortunately, there were no injuries.

The ATSB found that the journal and bearing on the wagon seized and lost interference fit. This generated high levels of frictional heating between the bearing and axle journal, and the subsequent torsional shearing failure of the axle (a ‘screwed journal’). The axle failure immediately caused the leading axle of the trailing bogie to derail.

The ATSB concluded that a loss of lubrication or an internal bearing cage failure was the most likely contributor to the bearing breakdown and seizure. Evidence also suggested the breakdown developed relatively rapidly, given the absence of a positive fault detection from two bearing acoustic monitoring systems (RailBAM®) passed on the day of the occurrence.

Safety message

Bearing failures leading to derailment continue to occur within the Australian rail network. Rail operators must continue to be vigilant and ensure axle bearings, and in particular axle box type bearings, are correctly installed, maintained and monitored throughout their life.

Read the final report: Derailment of freight train 2AD1, near Hugh River, Northern Territory, on 23 December 2014

On 15 January 2014, a Sydney Trains service made up of two four-carriage Tangara electric multiple units entered the underground section of the Eastern Suburbs Line under Sydney city centre heading towards its destination, Bondi Junction.

Some smoke and a burning smell were apparent emanating from the train at Central station and at all subsequent stations to Bondi Junction. A number of station and train crewing staff were aware of this but the condition was not reported to the appropriate network control officer as required under Sydney Trains’ Network Rules and Procedures.

The train terminated at Bondi Junction where a different driver took control of the train before it departed on its return journey. It then travelled to the next station, Edgecliff.

Shortly after departure from Edgecliff, at 1726, the lead bogie of the third carriage derailed due to a broken axle on the leading bogie of the third carriage. A piece of angle iron that became dislodged from the track infrastructure penetrated the floor of the third carriage and entered a space occupied by passengers. Fortunately, no passengers or train crew were injured.  

The ATSB found that an unauthorised, non-standard repair had been carried out on the axle in December 1998 or January 1999 which introduced stress initiators, causing a crack to develop which over time propagated to the extent that the axle failed in service.

It was also determined that a number of organisational factors contributed to the incident. Poor communication and lack of adherence to procedures and reporting lines after the first problems were noticed, led to the train continuing in service and subsequently derailing. 

Seven axles, including the failed axle, had been repaired in the same way. All were immediately located and removed from service.

Sydney Trains produced a number of safety recommendations which are being incorporated into their Safety Action Management procedures.

Safety message

Rail operators should ensure that maintenance procedures are followed and that non-standard repairs comply strictly with an approved variation and do not introduce new risks to operations.

Also, rail operators should review their internal training and communication pathways to ensure that critical communication can occur in line with best Rail Resource Management principles.

Read the final report: Derailment of Sydney Trains Passenger Train 602M, near Edgecliff Station, Sydney, New South Wales, on 15 January 2014

A recent aviation incident involving a student pilot and instructor shows why it’s essential to have a positive exchange of flight controls during flight training.

The incident occurred when the student pilot and instructor were doing crosswind circuit training in a Victa 115 Airtourer. As the aircraft flared to land, a strong gust of wind blew it off the runway centreline to the left, and the aircraft bounced hard.

The student initiated a go-around, applying full power, but the aircraft still drifted further to the left. As the aircraft was not climbing, the instructor called “taking over” and the student handed over control. The instructor lowered the nose of the aircraft to gain airspeed.

The aircraft continued to drift further away from the runway centreline.

The student noticed the flaps were in the down position and, thinking it would assist, and without checking with the instructor, retracted the flaps to the up position.

There should never be any doubt about who is flying the aircraft.

The aircraft descended and about 100 metres past the threshold of the runway, it collided with the airport perimeter fence. After a further 20 metres, the aircraft flipped over the fence and came to rest upside down. The instructor and student exited the aircraft quickly through the broken canopy, as fuel was gushing from the fuel tanks. Both received minor injuries, and the aircraft was substantially damaged.

Source: Aircraft operator

Safety message

It is important in flight training to have a positive exchange of flight controls. The US Federal Aviation Administration (FAA) has found that numerous accidents have occurred due to a lack of communication or misunderstanding regarding who had actual control of the aircraft, particularly between students and flight instructors. The FAA publication Aviation Instructor’s Handbook(Opens in a new tab/window), includes a section on the Positive Exchange of Flight Controls. The handbook provides guidance to use for the positive exchange of flight controls

FAA positive exchange of flight controls

Source: US Federal Aviation Administration

Read the final report: Collision with terrain involving a Victa 115 Airtourer, VH-MUV, Leongatha Airport, Victoria, on 29 May 2015

On the morning of Saturday 5 October 2013, the pilot of a Rand Robinson KR-2 aircraft, registered VH-CTE, took off from an airstrip on private property 12 km west of Tumut, New South Wales. The pilot was reported to have intended flying to Holbrook, New South Wales, and return home the following evening.

When the pilot had not returned by early Sunday evening, authorities were notified. A search located the aircraft wreckage in the early morning on 7 October 2013. The wreckage was found about 450 m east-north-east of the departure airstrip. The pilot was fatally injured and the aircraft was destroyed by impact forces.

The pilot’s decision not to have proper maintenance performed on the aircraft most likely contributed to the ejection of the spark plug, resulting in the accident.

Data from a global positioning system receiver recovered from the wreckage identified that the pilot turned back towards the departure airstrip shortly after take-off. During the attempt to land back on the airstrip, the aircraft likely entered a stall. The pilot was unable to recover the aircraft before impacting terrain.

The ATSB’s examination of the wreckage found that a spark plug had been ejected from its respective cylinder head mount. The failure of the cylinder head spark plug mount was probably the result of an incorrectly installed thread insert. There were reports and evidence that the pilot maintained and modified the aircraft, despite not being qualified or authorised to do so. As well, in the previous 2 years, an authorised maintainer had not completed the required regular aircraft maintenance.

The pilot’s decision not to have proper maintenance performed on the aircraft most likely contributed to the ejection of the spark plug, resulting in the accident.

Safety message

Unauthorised maintenance increases the risk of mechanical failure. This, in turn, reduces the level of safety and increases the risk of injury or death.

Authorised aircraft maintenance is mandated to assure a level of safety for aircraft operations. That directive also identifies the requisite qualifications for the maintainer.

As well, managing airspeed and bank angle is critical to preventing an aerodynamic stall following partial engine failure after take-off. Research shows partial engine power loss is more complex and more frequent than a complete engine power loss. These accidents are typically a result of the aircraft entering an aerodynamic stall from a height where recovery is not possible.

More information on managing partial power loss after take-off is available from the ATSB’s avoidable accident web page.

Read the final report: Loss of control following partial engine failure involving amateur-built Rand Robinson KR-2, VH-CTE, 12 km west of Tumut, New South Wales, on 5 October 2013

A recent landing gear incident involving a Cessna 210 shows how as aircraft age, their original maintenance schedule may not be sufficient to ensure ongoing safety.

The Cessna 210, returning from a scenic flight with five passengers on board, was approaching to land at Kununurra Airport, Western Australia.

During the approach, the pilot selected the landing gear down but the landing gear down indicator light did not illuminate. The right and left main landing gear appeared to be down and locked but the pilot was unable to see the nose landing gear.

The pilot completed the relevant checklists and conducted a low-level pass over the runway so the aircraft’s operator could see from the ground if the landing gear was down.

As aircraft age, the original maintenance schedules may not be sufficient to ensure the aircraft’s ongoing safety.

The operator observed the landing gear and reported to the pilot that the landing gear appeared to be in the down position. The pilot returned for a landing on runway 12.

On landing, the main landing gear wheels touched down first. The pilot held full back pressure on the elevator controls to hold the nose wheel off the runway for as long as possible. After about 100 m, the nose of the aircraft sank on to the runway. At this point, the nose wheel collapsed, the propeller struck the runway, and the aircraft came to a stop. The pilot and five passengers were uninjured. The aircraft sustained minor damage, including damage to the propeller, nose wheel, and engine cowling.

The aircraft was last flown about three weeks before this incident, and the pilot reported that there was no outstanding maintenance.

This aircraft was manufactured in 1976 and, and at the time had 9,965 hours total time in service. The owner’s investigation into the incident determined that one of the nose landing gear down lock pins had failed. The pin failed in the area of the machined groove for the pin retention roll pin . The failed down lock pin migrated out and interfered with the nose landing gear actuator. This movement prevented the nose landing gear down lock mechanism from engaging in the down and locked position.

Failed nose landing gear downlock pin

Source: Aircraft owner

The Cessna nose landing gear downlock actuator pins have had a history of cracking and failing. In response, Cessna recommended the inspection of the pins to determine their safety.

Safety message

The incident highlights the importance of comprehensive, periodic maintenance inspections. It also shows the role manufacturers have in the continuing airworthiness instructions for maintaining ageing aircraft. As aircraft age, the original maintenance schedules may not be sufficient to ensure the aircraft’s ongoing safety. As a result of investigation report AO-2011-115 the ATSB encourages registration holders of class B aircraft to review their aircraft’s maintenance schedule to determine if it is the most appropriate for their aircraft and to ensure that it adequately provides for the continuing airworthiness of the aircraft.

In 2007, the ATSB released research report How Old is Too Old? The impact of ageing aircraft on aviation safety. The report found that some aircraft manufacturers have recognised that the original maintenance schedules may not be sufficient to ensure the aircraft’s (ongoing) safety. Those manufacturers have developed additional continuing airworthiness information.

In 2012, in recognition of the Australian general aviation aging aircraft fleet, CASA released a discussion paper Ageing Aircraft Management Plan (AAMP)(Opens in a new tab/window). The discussion paper makes the following relevant points:

• As an aircraft ages up to and beyond its original design assumptions, the nominated maintenance program needs to be modified to take into account ageing issues. In particular, inspections of key areas or components not usually accessed.
• CASA and Authorised Persons are obliged to take into account all relevant maintenance data or information pertinent to a particular aircraft type. This includes manufacturer’s data, Airworthiness Directives, Service Bulletins and other continuing airworthiness information.
• CASA Maintenance Schedule 5 was originally conceived as a minimum schedule of maintenance activities, to be undertaken on a very limited range of relatively simple, ‘orphan’ aircraft
• CASA Maintenance Schedule 5 was not originally intended to address ageing aircraft related issues. The literal application of this schedule on its own was not intended to replace the manufacturer’s instructions for continued airworthiness, where available.

The adequate maintenance of ageing aircraft requires the participation and ongoing cooperation of aircraft manufacturers, regulatory authorities, owners, operators, and maintainers.

Read the final report: Landing gear malfunction involving a Cessna 210, VH-SMP, Kununurra Airport, Western Australia, on 1 February 2015