Safety summary

What happened

On the morning of 4 March 2012, freight train 7SP3 operated by Pacific National derailed after entering floodwaters that had overtopped the track near Roto in New South Wales.

The flooding had caused scouring of the track formation, compromising its capacity to support the train.

The lead locomotive remained on the track but the trailing locomotive derailed and uncoupled. None of the trailing wagons derailed although a number sustained damage. The flooding and subsequent derailment of the second locomotive of train 7SP3 damaged approximately 130 m of track. The crew were shaken, but physically unhurt.

What the ATSB found

The ATSB determined that runoff from the heavy rain that had fallen in the catchment area adjacent to Roto the morning of 4 March 2012 caused a flash flood event. The volume of floodwater exceeded the capacity of a drainage culvert, which resulted in water overtopping the track formation with ballast and sub-grade scouring on either side of the culvert.

The magnitude of the scouring meant that the track could not support the weight of train 7SP3 as it passed over the affected areas. The resulting deformation in the alignment of the track initiated the derailment.

The ATSB also found that the track manager’s systems and operational procedures provided limited information and guidance to assist the network control staff in identifying and assessing the potential threat to the safety of rail traffic resulting from the significant localised weather event.

What's been done as a result

The track manager is trialling the use of flood sensors at high-risk locations and has engaged the services of a third party to provide early warning information on potential high-risk weather events.

Safety message

It is essential that rail transport operators have robust systems in place to monitor and mitigate the risks to infrastructure from significant weather events to ensure that the safety of rail operations is not compromised.

Why the ATSB is doing this research

One of the main objectives of air traffic services (ATS) is to prevent the collision of aircraft. Aircraft separation standards are set to ensure that the chance of a mid-air collision is very remote. When they are infringed, there are fewer defences left to guard against a mid-air collision. This ATSB research investigation looks at loss of separation (LOS) incidents in Australian airspace to understand how often they occur and in what contexts, how and why they are occurring, and whether there are any wider implications that the air traffic system is not functioning appropriately.

What the ATSB found

Although there had been an increase in the number of occurrences reported to the ATSB over the 2 years ending in June 2012, there were fewer LOS occurrences during that period than during 2005 to 2008. Traffic levels have generally increased during the same period. A LOS between aircraft under air traffic control jurisdiction happens on average about once every 3 days. In almost 90 per cent of LOS occurrences, there was no or minimal risk of aircraft colliding. On average, however, there are six occurrences per year where an elevated risk of collision exists. There have been no mid-air collisions in Australia between two aircraft under ATS control.

The investigation found that military controlled terminal area airspace in general, and all airspace around Darwin and Williamtown in particular, had a disproportionate rate of LOS (for civilian aircraft). Most of these LOS occurrences were contributed to by air traffic controller actions. This may be a result of the nature of aircraft operations and airspace constraints at some military airports, leading to reduced use and effectiveness of strategic separation defences, thereby placing more responsibility for separating aircraft directly onto the controllers. Furthermore, as military ATS are not subject to safety oversight by the Civil Aviation Safety Authority (CASA), there is no independent assessment and assurance as to the safety of civilian aircraft operations at military airports.

In civil airspace, LOS occurrences attributable to pilot actions are not monitored as a measure of airspace safety nor actively investigated for insight into possible improvements to air traffic service provision. As about half of all LOS incidents are from pilot actions, not all available information is being fully used to assure the safety of civilian airspace.

What's been done as a result

The ATSB has issued recommendations to the Department of Defence to review all processes and controls in place for aircraft separation in military ATS and to CASA to review whether its current level of involvement with military ATS is sufficient to assure the safety of civil aircraft operations. The ATSB also recommends using all available information, including pilot attributable LOS occurrences, to assure the safety of civilian airspace, and will itself investigate all serious LOS incidents.

Safety message

Aircraft separation is a complex operation with many levels of defences to avoid errors and to safely manage the results of the errors that will inevitably be made from time to time by air traffic controllers and pilots. The defences ensure that even if a LOS does occur, the chance of an aircraft collision is still very remote. Safety could be enhanced through understanding and addressing the reasons for the disproportionate rate of LOS occurrences involving civil aircraft in military airspace, and through the ongoing monitoring and investigation of all LOS incidents in civil airspace.

What happened

On 21 February 2012, at about 0900 Eastern Daylight-saving Time, at about 8 NM east of Gunnedah, New South Wales, a Piper aircraft company PA-39 aircraft registered VH-ICS (ICS) and a Pacific Aerospace CT/4B aircraft registered VH-YCR (YCR) were conducting instrument flight rules (IFR) flying training operations, in visual metrological conditions on a reciprocal track between Tamworth and Gunnedah. There was a flying instructor and two students on board ICS and a flying instructor and one student on board YCR.

YCR received traffic advice from Brisbane Air Traffic Services (ATS) on two other aircraft in the area below 5,000 ft, including ICS. YCR was nearing Gunnedah at 6,000 ft above mean sea level, and broadcast their intention to over-fly Gunnedah at 6,000 ft, on the Gunnedah common traffic advisory frequency. ICS then requested traffic information for a departure from Gunnedah to Tamworth, at 7,000 ft and later advised Brisbane ATS that they were 5 NM outbound from Gunnedah and passing 6,000 ft. Both aircraft were on the same bearing and unable to contact each other; both took evasive action at 6,000 ft. The PIC of YCR estimated that at the time of the event their separation was 1 NM laterally.  Neither crew sighted the other aircraft.

This incident highlights the importance of applying the principles of 'see and avoid' in conjunction with an active listening watch and clear communications when operating in the vicinity of a CTAF.

Aviation Short Investigation Bulletin - Issue 11

What happened

On 21 February 2012, a Robinson Helicopter Company R22 Beta helicopter, registered VH-HRY, collided with terrain 95 km south-west of Springsure aircraft landing area (ALA), Queensland. The pilot was the only person on board and was not injured. The helicopter was seriously damaged.

While en route from a private helicopter landing site near Springsure to Beauchamp Station, the pilot decided to land to close a gate and identified a suitable landing area located nearby. On approach to the landing area, the helicopter made an uncommanded turn to the right; the pilot immediately applied left pedal and forward cyclic to arrest the rotation. The rotation slowed with the helicopter facing downwind. The helicopter contacted the ground and rolled over.

This accident highlights the dramatic and rapid effect that a loss of 'yaw axis' directional control resulting from loss of tail rotor authority (LTA) or loss of tail rotor effectiveness (LTE) can have on helicopters.

What happened

On 17 February 2012, at about 1315 Central Standard Time, a Cessna 210, registered VH-RQD (RQD), was backtracking runway 18 for the general aviation parking area at Darwin airport, Northern Territory.  At the same time, a Cessna 310, registered VH-XXT (XXT), was holding at taxiway Echo 2 (E2) for an intersection departure from runway 29. 

The surface movement controller instructed RQD to cross runway 29 at about the same time as the aerodrome controller cleared XXT for take-off on runway 29. It was estimated both visually and by radar that XXT then overflew RQD crossing the runway by between 150 ft and 500 ft.

Runway incursions are recognised as an ongoing safety concern for the aviation industry and have been cited in numerous accidents world-wide. They can be the result of many different factors and involve pilots, controllers and vehicle drivers. This incident highlights the need for controllers to remain vigilant in monitoring and scanning the runway, both prior to, and after issuing take-off and runway crossing clearances to pilots.

Aviation Short Investigation Bulletin – Issue 17

What happened

The Australian Transport Safety Bureau (ATSB) was requested by the Civil Aviation Safety Authority (CASA) to assist in the examination of a number of aircraft flight control cable terminal fittings, to identify if they had been affected by stress corrosion cracking (SCC). The terminals had been manufactured from SAE-AISI 303 Se stainless steel (part numbers AN669 and MS21260) and were installed on Piper, Cessna and Beech aircraft. SCC is an environmental failure mechanism resulting from a combination of a susceptible material, applied (or residual) stress and a corrosive environment.

What the ATSB found

While several of the 54 submitted cable terminals showed evidence of surface pitting corrosion, none revealed any evidence of SCC when examined visually and using non-destructive testing techniques.

During the course of the ATSB examinations, CASA received fractured cable terminals from a Piper PA32 and an amateur built aircraft; these fittings were also submitted for examination. The failure mechanism in both cases was confirmed as SCC that had initiated on the external terminal surfaces. The ATSB was also advised of the additional failure of a terminal that was investigated by the New Zealand Civil Aviation Authority. The failure mechanism was also confirmed as SCC, however the cracking had initiated from the internal surface of the swaged terminal sleeve where it was in contact with the wire cable.

What's been done as a result

A number of actions have been taken in Australia and internationally to address the issue of SCC in control cable terminals manufactured from SAE-AISI 303 Se. The latest CASA airworthiness bulletin (AWB 27-001 Revision 3) updated owners on the potential for SCC of flight control cable terminals and urged operators to consider replacing the cables before they reach 15 years in service. A recent Federal Aviation Administration Airworthiness Directive (AD-2013-02-13) required the inspection of the stabilator control system on certain Piper aircraft and replacement of parts as necessary. CASA has also initiated a project that is seeking to amend Civil Aviation Order 100.5, ‘General requirements in respect of maintenance of Australian Aircraft’, to mandate a recurring inspection of terminals manufactured from SAE-AISI 303 Se which have a total time in service of 15 years or greater.

Safety message

The ATSB encourages owners, operators and maintainers of aircraft that may be fitted with cable terminals with part numbers AN669 and MS21260, to familiarise themselves with the issues surrounding terminal fitting corrosion and the associated risks to continued airworthiness. Personnel should familiarise themselves with CASA Airworthiness bulletin, AWB 27-001 and the US National Transportation Safety Board Safety Recommendations A-01-6 through -8 released on April 16, 2001. Both documents highlight the risk to continued safe operation associated with SCC of flight control cable terminals and provide a comprehensive background on the failure mechanism and experiences. The ATSB urges operators to consider replacement of the cables in line with the regulators guidelines, as experience has shown that inspection alone is not a complete defence against SCC failures.

Safety summary

What happened

On 16 February 2012, a Government Aircraft Factory N22C, registered VH‑ATO (ATO), was conducting a survey flight north-east of Melbourne Airport, Victoria when it was involved in two losses of separation with two Boeing 737 aircraft. The 737s, registered VH‑VZA (VZA) and VH‑TJY (TJY), were on approach to runway 27 at Melbourne Airport. All of the aircraft were in receipt of an air traffic control service.

What the ATSB found

Although air traffic control intended that the pilot of ATO should keep his aircraft separate from VZA and TJY using visual observation (visual (pilot) separation), not all the prerequisites for using this separation method were met. As a result, the onus remained on air traffic control to maintain either a vertical separation standard of 1,000 ft or a surveillance separation standard of 3 NM (5.6 km). Losses of separation occurred when separation between ATO and VZA reduced to 1.5 NM (2.8 km) and 300 ft, and between ATO and TJY when separation reduced to 1.7 NM (3.2 km) and 700 ft.

The ATSB also identified that the controller was not aware of how specific aspects of the survey operation were to be conducted and therefore could not be assured that separation would be maintained.

Additionally, the ATSB identified that limited guidance and training was provided to controllers operating outside the towered environment in the application of the visual (pilot) separation standard, increasing the risk of the incorrect application of the standard.

What's been done as a result

In response to these occurrences, Airservices Australia amended the Manual of Air Traffic Services to include a number of factors to be considered by air traffic controllers prior to assigning visual (pilot) separation. In addition, the training package for Melbourne Airport arrivals controllers was reviewed and updated to ensure that visual separation, transfer of separation responsibilities and associated phraseologies were adequately addressed. Finally, the controller checking regime was strengthened to ensure that any identified training and/or knowledge deficiencies in relation to assigning visual separation, and their impact on controller performance, were addressed.

Safety message

The use of visual (pilot) separation transfers responsibility for separation between aircraft operating in controlled airspace from the air traffic controller to the flight crew of one of the aircraft. This occurrence highlights that, for the standard to be effective, all parties must have a shared understanding. Correct application of the visual (pilot) separation standard ensures that all involved flight crew are aware of their responsibility, thereby assuring that aircraft will not come into unsafe proximity.

At about 0615 on 2 February 2012, the 42.7 m passenger ferry Rabaul Queen capsized and sank about 9 nautical miles off the Papua New Guinea (PNG) town of Finschhafen. Two hundred and forty six people were rescued during a search and rescue operation that was coordinated by the PNG Maritime Rescue Coordination Centre and the Australian Rescue Coordination Centre. However, at least 142 people are thought to have died as a result of the sinking.

On 16 February, following a request from the PNG Government, four officials from the Australian Transport Safety Bureau (ATSB) travelled to the PNG capital Port Moresby to offer initial advice to local authorities in safety aspects of the investigation into the sinking.

From that time until 28 June 2012, two ATSB transport safety investigators provided assistance to the PNG Government's Commission of Inquiry into the sinking of Rabaul Queen in accordance with Section 12AA (2)(a)(iii) of the Transport Safety Investigation Act 2003. This part of the ATSB’s governing legislation provides for cooperation with authorities in other countries in the interest of transport safety.

The Commission of Inquiry’s final report was presented to the Prime Minister of PNG on 28 June 2012 and it was subsequently tabled in parliament on 5 September 2012. Information, including the Commission of Inquiry's terms of reference, hearing transcripts and final report can be found at: http://www.coi.gov.pg/rabaulqueen.html

Safety summary

What happened

On 15 February 2012, a Toll Aviation Pty Ltd Fairchild Industries Inc SA227 Metro III aircraft, registered VH-UZA, was being operated on a post-maintenance acceptance flight in the circuit at Brisbane Airport, Queensland with two crew on board. On selection of the landing gear handle to the down position, the landing gear would not extend. After unsuccessful attempts to extend the landing gear in both normal and emergency gear extension modes, the crew decided to conduct a wheels-up landing. At about 0230 Eastern Standard Time the aircraft landed along the centreline of runway 19. The crew evacuated without injury and the aircraft sustained substantial damage.

What the ATSB found

The ATSB found that an electrical wire to the landing gear selector valve had separated at a connector adjacent to its terminal preventing normal operation of the landing gear to the down position. The investigation also identified an out of rig condition in the landing gear emergency extension system, which prevented correct operation of that system. Factors including the maintenance practices by a number of personnel and inconsistent maintenance documentation contributed to the existence of the defects.

What's been done as a result

The aircraft manufacturer advised that, as a result of this occurrence, re-routing requirements for the landing gear selector valve electrical wiring loom in the Metro aircraft have been distributed to all Metro operators through a Metro Global advisory publication.

The operator carried out a fleet-wide check of the landing gear on its Metro aircraft and rectified any defects found. The operator also re-routed the electrical wiring loom to the landing gear selector valve. In addition, the operator amended the pilot’s quick reference handbook and the Metro phase inspection worksheets and issued an engineering memorandum to all aircraft maintenance personnel detailing the operator’s requirements with regards to following standard procedures and approved data for maintenance tasks.

Safety message

This investigation highlights the importance of operators and approved maintenance organisations having a detailed understanding of the systems installed on the aircraft types that they are authorised to certify and aircraft manufacturers providing clear and concise maintenance procedures in an aircraft’s suite of manuals.

Safety summary

What happened

At about 1555 Eastern Daylight-saving Time on 4 February 2012, a Robinson R44 helicopter, registered VH‑COK, lifted off from Jaspers Brush Aerodrome, New South Wales for aerial photography of the launching of a deep-sea submarine in nearby Jervis Bay. On board the helicopter were the pilot and a camera operator.

Soon after lifting off the pilot’s door opened, and the pilot reached out to close the door. Simultaneously the helicopter abruptly pitched nose-up then steeply nose-down, rolling to the right before the right landing gear skid and main rotor blades struck the ground. A fuel-fed fire started in the vicinity of the fuel tanks and lower mast area prior to the helicopter coming to a stop. Both occupants were fatally injured, and the helicopter was destroyed.

What the ATSB found

The Australian Transport Safety Bureau (ATSB) found that the pilot’s door was not properly latched prior to lift off and opened during the turn to depart. In attempting to shut the door the pilot probably let go of the cyclic control from the normal (right) control hand, allowing for an unintended, abrupt nose-up pitch and the helicopter tail hitting the ground. The helicopter nosed over and impacted the ground. A fire began when one of the fuel tanks was breached.

The ATSB identified that the fatal injuries were due to the post-impact fire, as was the case in a number of other R44 accidents. A number of these R44s, including VH‑COK, had not and were not yet required to have been modified in accordance with a manufacturer service bulletin that specified replacement of aluminium fuel tanks with more impact‑resistant bladder‑type fuel tanks. The installation of these tanks decreased the risk of a post‑accident fire. At the time of the accident, these tanks were required to be fitted by 31 December 2014.

What's been done as a result

In response to this and a number of other fatal accidents in other R44 helicopters, the Civil Aviation Safety Authority (CASA) and the ATSB have separately highlighted the benefits of the upgraded bladder-type fuel tank and related modifications to operational and maintenance personnel. In addition, the helicopter manufacturer has progressively reduced the compliance time on service bulletin SB-78 in respect of the installation of the bladder‑type fuel tanks to 30 April 2013. A second bulletin aimed at removing a possible impact‑related ignition source was also issued and the manufacturer is issuing advisory information emphasising the importance of maintaining control of the helicopter during an unexpected event.

Safety message

This accident highlights the importance of ensuring all doors are secured prior to take-off. That said, the opening of a door in flight will not normally affect the operation of an R44, but the instinctive reaction to immediately deal with such an event can be quite strong. Pilots need to be aware that this reaction may be hard to overcome and in the event of an unexpected situation occurring such as the opening of the door, it is vital that pilots should continue to ‘fly the aircraft’. This includes choosing to land to close the door if necessary. The fitment of bladder-type fuel tanks to R44 helicopters is a worthwhile safety enhancement that could save lives and advice from CASA is that their installation in accordance with the manufacturer’s service bulletin by 30 April 2013 is mandatory.