Running line collision

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Source: Google Earth, annotated by ATSB

A collision involving a track worker and a passenger train at Petrie Station, north of Brisbane, highlights the need for sufficient resources, including time, information about the work environment, train movements and adequate protection to minimise risk to rail workers, a new ATSB investigation report says.

Late in the evening on 29 May 2017, a passenger train approaching Petrie Station from the north struck and fatally injured a Queensland Rail (QR) protection officer. He was part of a team of four protection officers implementing a planned track closure for maintenance of the Kippa-Ring rail corridor from Petrie Station to Kippa-Ring station. The protection officers were using personal continual vigilance (PCV), which requires track workers to see that tracks are clear, frequently look in both directions for approaching rail traffic and not rely on another person to give warning, when walking within three metres of a track (known as the Danger Zone).

The protection officer had placed permanent way protection* to warn approaching train drivers to stop and mark the outer limits of protection for the track maintenance worksite on the Kippa-Ring lines. The collision occurred while the protection officer was walking on the Up Caboolture line, which was open for rail traffic and not part of the track maintenance worksite.

The ATSB’s investigation found that the protection officer did not apply personal continual vigilance techniques while walking within the track Danger Zone. The investigation noted that while it was evident that immediately prior to the collision the protection officer’s attention was diverted by the mobile phone clipped to the front of his shirt illuminating, the protection officer was already in a position of danger with a collision imminent by this point, and the direction he was walking meant that his back was facing the train involved in the collision.  

This investigation highlights that to minimise risk, rail organisations should ensure processes relating to track work include provisions for protection officers to have sufficient resources, including time for task, information about the work environment, including train movements, and adequate protection available for the work.

“Although the reasons why the protection officer did not apply continual vigilance techniques could not be determined, it was possible that he had no expectation of rail traffic, and a number of factors that increased risk were identified,” ATSB Director Transport Safety Dr Godley said.

Those factors included time pressures, protection officers not being familiar with the new rail infrastructure layout at Petrie Station for the Kippa-Ring line (which officially opened in October 2016), no processes being in place for ensuring adequate time for protection officers to familiarise themselves with new or changed work sites, and the night shift protection officer supervisor inadvertently marking some open lines as closed on the Train Notice Diagram for Petrie Station that was used by the protection officers. Independent verification of the Train Notice Diagram was not undertaken, and so that error was not identified.

“This investigation highlights that to minimise risk, rail organisations should ensure processes relating to track work include provisions for protection officers to have sufficient resources, including time for task, information about the work environment, including train movements, and adequate protection available for the work,” Dr Godley said.

In response to the accident, QR have commissioned a number of independent reviews on its safe work on track processes and practices, including the use and selection of personal continual vigilance, mobile devices in the rail corridor and its worksite protection compliance inspection systems.

QR have also re-enforced the message of ‘the right to stop work and getting safety right before commencing’ as part of its ongoing network pre-start brief project.

* Permanent way protection: One or more devices approved by Access Providers that provide warning to protect rail traffic crew and workers. The device or devices may be used in conjunction with signalling or blocking facilities.

Read the final report: Running line collision with worker involving passenger train T570, Petrie, Queensland, on 29 May 2017

Loss of containers

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Source: ATSB

The loss of 81 containers overboard from the container ship YM Efficiency highlights the importance of safe and effective container stowage planning, an ATSB investigation has found.

Just after midnight on 1 June 2018, the YM Efficiency was steaming slowly into strong gale force winds and very rough seas off Newcastle, en route to Sydney, when it suddenly rolled heavily, causing container stacks to collapse and topple. As a result, 81 containers were lost overboard and a further 62 were damaged, while the ship sustained structural damage to its lashing bridges, superstructure, and accommodation ladder.

Substantial debris from the lost containers subsequently washed ashore on the New South Wales coast. At the time of the ATSB investigation report’s finalisation, search efforts for those containers – including with the use of remote underwater vehicles – had identified 66, with a few having washed ashore or close to shore. Five containers have been removed, and 15 containers have yet to be found.

Source: ATSB

The ATSB investigation determined that the forces generated during the sudden, heavy rolling placed excessive stresses on containers stowed aft of the ship’s accommodation. This resulted in the structural failure of containers and components of the lashing system, leading to the loss of containers overboard.

All potential causes for the sudden rolling were investigated, such as the possibility of an abnormal wave, but there was insufficient evidence to establish a definitive cause.

Further, the condition of the ship’s lashing equipment was considered not to have contributed to the loss of containers. However, the investigation found that the weights and distribution of containers in the affected bays were such that calculated forces exceeded allowable force limits as defined in the ship’s Cargo Securing Manual (CSM).

Dislodged containers six days after the accident

Figure 11: Dislodged containers six days after the accident.
Source: ATSB

Source: ATSB

ATSB Chief Commissioner Greg Hood said the safe carriage of containers at sea depends on loading, stowing, and securing them in compliance with the ship’s CSM.

“Checking stowage plans for compliance with the Cargo Securing Manual requirements is increasingly achieved through loading computer systems. Notwithstanding the efficiency of computerised loading systems, the scale and pace of modern container ship operations puts significant pressure on ship’s officers to check and amend or approve proposed stowage plans at a late stage.”

Mr Hood noted that in that context, the planning process ashore offers the best opportunity to take all practical measures to ensure that the proposed stowage plan presented to ships officers complies with the CSM and is as safe as reasonably practicable.

The ATSB investigation found that the weights and distribution of containers in the affected bays were such that calculated forces exceeded allowable force limits as defined in the ship’s CSM. The investigation also identified that the stowage arrangement was not checked for compliance with the CSM’s calculated lashing force limitations during the cargo planning process ashore.

“This left sole responsibility for compliance with the ship’s officers, with limited options to resolve deficiencies at a late stage in the process without unduly impacting operations,” Mr Hood said.

Further, the officers did not use the ship’s loading computer system and its lashing calculation program to check if the stowage arrangement complied, as they probably did not have an adequate understanding of the system.

“Weather forecasting, routing and good navigational practices in adverse weather all play a part in minimising the risk of injuries to crew and damage to ship, cargo and environment,” Mr Hood said.

“However, safe and effective container stowage planning is the primary control measure in managing the risks involved in carrying containers by sea.”

As a result of this accident, the ship’s managers, Yang Ming, have taken a number of safety actions to address the identified issues. These include requiring checks of lashing forces during the initial cargo stowage planning stage ashore, providing regular training of shore planners in multiple aspects of cargo loading and securing, and training responsible ship’s officers in the use of the ship’s loading computer system.

“The ATSB considers that the safety actions taken by Yang Ming have adequately addressed the issues that our investigation identified,” Mr Hood said.

Read the final report: Loss of containers overboard involving YM Efficiency, 16 NM east-south-east of Newcastle, New South Wales, on 1 June 2018

Landing accident

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Source: South Australia Police

An ATSB investigation into a landing accident involving a Van’s RV-6A at William Creek, South Australia on 28 July 2019 found that the aircraft’s nosewheel landing gear’s strut or fork made contact with the runway, bending the nose gear under the aircraft.

The accident occurred when the aircraft was landing on an unsealed runway at William Creek. During the landing, the aircraft’s main gear touched down first, before the nose gear touched down momentarily. The pilot would later note that although the nose gear lifted off the runway, the main gear stayed on the runway.

When the nose gear made contact with the runway surface for the second time, it bent under the aircraft. The propeller then struck the runway and the aircraft skidded on its nose before flipping over coming to a rest inverted. The pilot sustained serious injuries and the passenger minor injuries, while the aircraft was substantially damaged.

Pilots of tricycle variants of Van’s aircraft need to take into account the many factors that can affect the ground clearance of their aircraft’s nose gear.

The ATSB investigation found that during the landing sequence the nose gear fork or strut made contact with the runway surface and bent underneath the aircraft. The investigation also established that the nose gear’s strut and fork had sustained no fractures, and that instead, the top of the strut had bent, near the engine mount.

“A reduction in the nose gear ground clearance during landing can result in the nose gear strut or fork impacting the runway and affect the structural integrity of the nose gear,” said ATSB Director Transport Safety Stuart Macleod.

“In the tricycle variants of Van’s aircraft, the factors that can affect nose gear ground clearance include the dynamics of the landing, tyre pressure, weight over the nose gear, and runway condition and characteristics.”

In 2007, Van’s issued a mandatory Service Bulletin with a redesigned nose gear that provided greater clearance. The aircraft that flipped at William Creek was compliant with this Service Bulletin and was also fitted with two after-market devices aimed at reducing the risk of a nose-gear collapse and aircraft inversion.

Read the final report: Landing accident involving Van’s RV-6A, VH-ANU, William Creek ALA, South Australia, on 28 July 2019

Carburettor corrosion

Corrosion in the carburettor of a Cessna 182’s engine, which led to a power loss after take-off and a subsequent forced landing, demonstrates the importance of following maintenance periodic inspection requirements. 

On the morning of 6 January 2019, Cessna 182 registration VH-DGF took off from Tooradin Airfield, Victoria for skydiving operations with the pilot and four parachutists onboard. The aircraft continued to climb but at about 400 ft the engine sustained a sudden power loss. Climb performance was affected and the propeller windmilled.  

The pilot lowered the aircraft nose and identified a suitable location for a forced landing. The aircraft touched down in a relatively flat and open paddock and initially bounced and passed through two boundary fences. The left wing strut then collided with a tree, folding the left wing over on top of the right wing. The Cessna then collided with a third fence, crossed a private road and collided with a fourth fence collapsing the nose landing gear where it come to a stop.

With limited time and height available, the pilot displayed sound airmanship and decision making.

The aircraft was substantially damaged, but there were no injuries to the pilot and passengers. However, the investigation report does note that by not wearing the available upper torso restraint the pilot exposed himself to significant unnecessary injury risk, and highlights that a substantial body of research shows that wearing an upper torso restraint significantly reduces the risk of injury compared to just wearing a lap belt only. 

Following the accident, subsequent examination of the carburettor found a significant amount of aluminium oxide deposits in the carburettor float bowl and directly below the carburettor nozzle and main jet assembly.  

Loose aluminium oxide deposits likely blocked fuel flow within the carburettor resulting in the engine losing power shortly after take-off. 

With limited time and height available, the pilot displayed sound airmanship and decision-making by accepting the risk of a minor accident and conducting a forced landing rather than turning back and risking loss of control and the possibility of a much more serious outcome, the report notes. 

This investigation also highlights the importance of following the maintenance program for your aircraft to ensure its serviceability, particularly as in this case, draining and flushing the carburettor at its periodic inspection. 

The ATSB was unable to determine the extent to which this action was actually conducted during the six inspections since the engine and carburettor were overhauled in December 2011.   

Read the final report: Loss of power on take-off and forced landing involving Cessna 182, VH-DGF, Tooradin, Victoria, on 6 January 2019

Execution of checklists

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Source: Cobham

Ineffective execution of checklists and the absence of nose-wheel chocking contributed to an Avro RJ85 airliner rolling forward after engine start and colliding with aircraft stairs and a light pole at Perth Airport, a new ATSB report details.

During the 30 July 2019 occurrence, the flight crew of a Cobham Aviation Avro RJ85 were preparing their aircraft for departure for a charter flight with two cabin crew and 62 passengers on-board.

The subsequent ATSB investigation found that the flight crew did not effectively check the brake system pressure during two separate pre-flight checklists, which meant they did not detect that there was insufficient pressure within the braking system, and did not identify that the system needed to be pressurised prior to engine start. (The aircraft had been parked after its previous flight for a number of hours; longer than the brake accumulator reservoir could retain pressure.)

The ATSB found that the initial and primary missed checks related to the captain not performing checklist items as required, and the first officer not effectively monitoring the checking actions of the captain and not independently checking the pressure systems.

Because of the missed checklist items, on engine start there was no brake pressure in the aircraft’s parking brake system. Once the captain gave the ground engineer clearance to remove the main wheel landing gear chocks, there was no other restraint in place to prevent an inadvertent roll forward, as the operator’s procedures did not involve repositioning chocks on the nose-wheel of departing aircraft.

Once started, the combined thrust of the aircraft’s four engines at idle power and the slight apron slope caused the aircraft to inadvertently roll forward.  The crew attempted to apply the aircraft brakes. However, because there was no brake pressure, these attempts were ineffective.

The normal after-start checks would have pressurised the brakes, however because the crew were responding to the unexpected roll-forward, they did not perform these checks. The ATSB found that the crew had a very limited opportunity to take corrective action to prevent the collision. The close proximity of the edge of the apron and the surprise associated with the unexpected roll-forward reduced the crew’s ability to respond before it collided with portable aircraft stairs. The aircraft then collided with a bollard in front of a light pole, and then the light pole itself.

“This investigation highlights the importance of ensuring all checklist items are addressed,” says ATSB Executive Director Transport Safety Nat Nagy.

“As highlighted in this accident, individuals can be vulnerable to omitting checklist items and this can lead to accidents.

“Aviation safety relies on a resilient safety system involving multiple defences. In the context of multi-crew operations, one of the key defences against this type of accident is the other pilot monitoring and cross-checking the pilot who is completing the checklist. This can provide a last line of defence to trap individual errors.”

Mr Nagy also noted that although safety systems should seek to reduce errors developing, where possible engineering defences, like wheel chocks, should also be used to reduce error consequences.

The report notes that Cobham have reiterated to their check and training captains the importance of vigilance during checklists, and that they were planning to update procedures to require the use of nose-wheel chocks when dispatching aircraft from stand-off bays.

Read the final report: Ground collision with airport infrastructure involving British Aerospace AVRO 146-RJ85, VH-NJW, Perth Airport, Western Australia, on 30 July 2019

Loss of power, high drag

After a loss of engine power, probably due to insufficient fuel or an in-flight fuel management error, a twin-engined Cessna 310 aircraft did not maintain a safe flying speed before it collided with terrain just short of the runway, an ATSB investigation has found.

The Cessna T310R was on approach to land at a private airfield at The Lakes, adjacent to the Pacific Highway south of Port Macquarie on the NSW North Coast, while conducting a private flight from Toowoomba, Queensland, with a pilot and passenger on board. When the aircraft was about 8 km from the runway, a witness recalled hearing what he thought was a single-engine aircraft ‘cough’ and then stop. A separate witness, who was driving south on the Pacific Highway, recalled seeing the aircraft descending slowly, then roll to the left, pitch down and descend rapidly to the ground.

The aircraft was subsequently found to have collided with terrain, coming to rest in a narrow-wooded strip of land between the highway and the main northern railway line, about 800 metres from the runway threshold. The pilot and the passenger were fatally injured, and the aircraft was destroyed in the accident.

The ATSB investigation identified that during the final descent, the aircraft’s left engine was not producing power and the right engine was operating at low or intermittent power. The loss of engine power was probably the result of either insufficient fuel for the flight or an in-flight fuel management error.

It is imperative that the pilot retains control of the aircraft and maintains a safe airspeed.

Despite that power loss, examination of the wreckage identified that the aircraft was configured for a powered approach, in a high‑drag configuration with the left and right engine propellers unfeathered, the landing gear down and the flaps partially extended. The low engine power combined with the high-drag configuration meant that the aircraft’s speed and altitude could not be maintained.

The investigation report notes that maintenance of a high‑drag configuration while the aircraft’s performance declined indicated that either the pilot did not recognise any engine abnormalities until late in the approach or assessed that sufficient engine power remained to reach the runway.

ATSB Chief Commissioner Greg Hood said this accident highlighted how a loss in power requires different responses depending on whether an aircraft has single or multiple engines.

“However, regardless of the configuration, in order to maximise the survivability outcome, it is imperative that the pilot retains control of the aircraft and maintains a safe airspeed,” Mr Hood said.

“Where the aircraft’s performance degrades to the point that continued safe flight is not possible, the pilot must shift their focus to conducting a forced landing.”

Mr Hood also stressed that pilots need to routinely follow recognised fuel management practices in order to maintain the highest level of safety and avoid fuel exhaustion or starvation events.

The Civil Aviation Advisory Publication 234-1(2)(Opens in a new tab/window) provides important guidance on the current fuel requirements and good fuel-management practices.

Read the final report: Loss of control and collision with terrain involving Cessna T310R, VH-JMW, 40 km south-south-west of Port Macquarie, New South Wales, on 28 October 2017

Nicotine withdrawal

The driver of an empty passenger train that passed two signals at ‘Danger’ and entered a level crossing before the crossing booms had lowered was probably influenced by nicotine withdrawal symptoms, an ATSB investigation has found.

The 2 January 2018 incident occurred when a V/Line three-car VLocity train (number 7750) was repositioning on a non-passenger-carrying service from the outer Geelong, Victoria suburb of Waurn Ponds to Geelong Station, from where it was due to operate a passenger service to Melbourne’s Southern Cross Station. Shortly after passing Marshall Station, the train passed two signals at Danger (MSL10 and MSL8), entered the single line section between Marshall and South Geelong, and then entered the Marshalltown Road level crossing before the crossing booms had lowered.

At about the same time a V/Line Melbourne to Warrnambool service, with two crew and 166 passengers on-board, had departed Geelong and was heading towards Marshall on the same single line section. The trains were scheduled to cross using the loop track at Marshall. When the train controller in Melbourne became aware that train 7750 was passing signals at Danger, the controller initiated an emergency radio fleet call instructing both trains to stop. When stopped, the distance between the trains was about 940 metres.

The subsequent investigation into the occurrence, conducted on behalf of the Australian Transport Safety Bureau (ATSB) by the Victorian Government Office of the Chief Investigator, Transport Safety, determined that the driver’s performance was probably influenced by symptoms associated with nicotine withdrawal, having not applied a nicotine patch on that day.

Attempts by safety-critical workers to stop smoking should be managed under medical supervision.

The investigation report notes that nicotine withdrawal symptoms typically become apparent within a few hours of last nicotine exposure, and that task-related effects can include difficulty concentrating, memory impairment and attention difficulties. These and other symptoms of nicotine withdrawal probably had an adverse effect on the performance of the driver.

Further, the driver of train 7750 also tested positive for an inactive metabolite of cannabis, with levels suggesting use within the previous seven days. However, it could not be determined whether cannabis use had affected the driver’s performance at the time of this incident.

“Nicotine withdrawal can affect a driver’s performance. To minimise adverse impacts, attempts by safety-critical workers to stop smoking should be managed under medical supervision,” said Chris McKeown, Chief Investigator, Transport Safety.

The report also notes that at the time of the incident, signalling at Marshall did not include any additional enforcement controls to protect against a train exceeding its authority.

Subsequent to the incident, V/Line installed a train protection system at Marshall to stop a train that has passed a signal at Danger. The system also has several over-speed sensors to prevent a train entering the Marshalltown Road level crossing when unprotected.

As part of other infrastructure projects, V/Line also continues with planning for the provision of three-position signalling for this section of track.

“This investigation highlights that rail operators should consider fitting authority-overrun intervention at locations, such as at Marshall, that present a heightened risk due to rail operations on a single, bidirectional track,” Mr McKeown said.

Read the final report: Signals passed at danger by train 7750, at Marshall, Victoria, on 2 January 2018

Technical assistance to the Civil Aviation Authority of the Philippines – Aircraft Accident Investigation and Inquiry Board investigation of an accident involving a Beechcraft King Air 350, RP-C2298, about 41 km south of Manila, on 1 September 2019

Summary

On 1 September 2019, a Beechcraft King Air 350 aircraft registered RP-C2296, on an aeromedical flight from Dipolog Airport to Manila collided with terrain at Brgy. Pansol, Calamba, Laguna, Philippines about 41 km south of Manila. All of the nine occupants received fatal injuries.

The Civil Aviation Authority of the Philippines – Aircraft Accident Investigation and Inquiry Board (AAIIB) requested assistance from the Australian Transport Safety Bureau (ATSB) to download the aircraft’s cockpit voice recorder (CVR).

To facilitate this support and to provide the appropriate protections for the CVR information, the ATSB appointed an accredited representative in accordance with paragraph 5.23 of ICAO Annex 13 and commenced an investigation under the Australian Transport Safety Investigation Act 2003.

On 8 October 2019, the Fairchild A100S cockpit voice recorder (CVR) from RP-C2296, which was severely fire damaged (Figure 1), was brought to Australia by two AAIIB investigators. In the presence of the AAIIB investigators, the CVR was successfully downloaded at the ATSB data recovery facility in Canberra, Australian Capital Territory. All data recovered from the CVR was provided to the AAIIB investigators to assist with their Annex 13 investigation.

Figure 1: Fairchild A100S CVR from RP-C2296

Cockpit voice recorder

Source: ATSB

The Philippines AAIIB is responsible for the investigation and release of the investigation report regarding this accident. Any enquiries regarding the investigation should be addressed to the Philippines Aircraft Accident Investigation and Inquiry Board at the contact details listed below:

Aircraft Accident Investigation and Inquiry Board
Civil Aviation Authority of the Philippines
Email: aaiib@caap.gov.ph
Web: www.caap.gov.ph

Occurrence summary

Investigation number AE-2019-054
Occurrence date 01/09/2019
Location Brgy. Pansol, Calamba, Laguna, about 41 km south of Manila, Philippines
Report release date 07/01/2020
Report status Final
Investigation level Defined
Investigation type External Investigation
Investigation phase Final report: Dissemination
Investigation status Completed
Mode of transport Aviation
Aviation occurrence category Collision with terrain
Occurrence class Accident
Highest injury level Fatal

Are you operating your amateur-built helicopter as designed?

Operating an amateur-built experimental helicopter outside the recommended design intent can potentially expose the helicopter to unintended stresses, and lead to the failure of critical components in-flight.

What happened

On 28 July 2015, the pilot and owner of an amateur-built Cicaré CH-7BT helicopter, registered VH‍-JEW, was conducting a ferry flight from Indee Station to Roy Hill Station, Western Australia. When about 8.5 NM north‑east of Roy Hill Station, the stabiliser assembly fractured leading to an in-flight break up and collision with terrain. The pilot was fatally injured and the helicopter was destroyed.

Amateur-built Cicaré CH-7BT helicopter, registered VH-JEW

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Source: Andrew Miles

Why did it happen

The ATSB examined the helicopter wreckage and identified that the stabiliser had separated in‑flight from the tail boom as a result of fatigue cracking of the stabiliser mount. This was the second fatal accident in Australia involving in-flight stabiliser separation on a Cicaré CH-7B helicopter (In-flight break-up involving Cicaré CH-7B, VH-SWQ, 43 km north-west of Barcaldine Airport Queensland on 12 May 2014 (AO-2014-086)).

During the course of the investigation, the ATSB found that a number of these amateur-built helicopters were being used for mustering operations, although the manufacturer stipulated that they were designed for recreational and sport use only. In addition, the ATSB established that both VH-JEW and VH-SWQ were fitted with external storage accessories, likely without the appropriate engineering assessment to ensure there would be no adverse effects on the performance, handling and structure of the helicopter. Although not the only contributors to the development of these accidents, operating outside the manufacturer’s design intent and limitations has the potential to induce stresses on the aircraft, leading to premature wear and possible failure.

Safety advisory notice

AO-2015-089-SAN-014: Operating an amateur-built helicopter within the stated design intent and limitations is essential for safe conduct of flight. The ATSB advises owners/operators to be aware of the risks associated with operating amateur-built helicopters outside the limitations prescribed by the manufacturer. For example, mustering operations and the addition of unapproved modifications, can potentially produce unintended stresses on the airframe leading to the premature failure of components.

Read more about this ATSB investigation: In-flight break-up involving Cicaré S.A. CH-7BT helicopter, VH-JEW, near Roy Hill Station, Western Australia, on 28 July 2015

Publication details

Investigation number AO-2015-089-SAN-014
Publication type Safety Advisory Notice
Publication mode Aviation
Publication date 20/12/2019

Operate within design intent

The fatal in-flight break-up of a Cicaré CH-7 helicopter highlights the importance of operating amateur-built helicopters within their design intent to avoid unintended stresses, and ensuring that any modifications are assessed for the effects on structural integrity and handling.  

On 28 July 2015, the pilot/owner of an amateur-built (kit-assembled) Cicaré CH-7BT helicopter, registration VH-JEW, departed Indee Station in Western Australia for Roy Hill Station for planned aerial mustering work the next day. When about 8.5 NM north-west of Roy Hill Station, the helicopter’s stabiliser assembly fractured and separated from the tail boom, leading to the separation of the mast and main rotor. The helicopter then collided with terrain, fatally injuring the pilot.

During the subsequent ATSB investigation, examination of the recovered components found that the stabiliser mount had fractured due to overstress following the propagation of a fatigue crack in the area adjacent the weld. The crack had likely to have been present for some time prior to the final fracture.

While the ATSB was unable to fully determine the reasons for the initiation and propagation of the fatigue crack, it was likely the result of some combination of the design, operating conditions, and untested accessories. The helicopter had been fitted with an external storage pod, likely without the appropriate engineering assessment to ensure that the pod would not have an adverse effect on the helicopter’s performance, handling and structure.

The ATSB also found that, although the CH-7B was intended for recreational use only, this and other CH-7B helicopters had been used for aerial mustering. Operating outside the manufacturer’s design intent had the potential to induce stresses on the aircraft, leading to premature wear of components and possible failure.

“Aerial mustering can involve extremely frequent manoeuvring and rapid power changes that can apply very high loads on a helicopter that may be quite different to the type of flying for which it was designed,” ATSB Director Transport Safety Dr Stuart Godley said.

“The ATSB is advising the Australian agricultural mustering community that the manufacturer, Cicaré S.A., has stated these helicopters are not intended or recommended for aerial work, particularly mustering operations.”

“The ATSB is also advising owners and operators of amateur-built helicopters that, operating within their stated design intent and limitations is essential for safe flight. This also includes the addition of unapproved modifications or external accessories.”

Dr Godley noted that mustering operations and the addition of unapproved modifications, outside the limitations prescribed by the manufacturer, can potentially produce unintended stresses on the airframe leading to the premature failure of components.

“A Safety Advisory Notice is currently being distributed to Cicaré helicopter owners highlighting the risks associated with operating amateur-built helicopters outside of their design intent.” 

Safety Advisory Notice AO-2015-089-SAN-014: Are you operating your amateur-built helicopter as designed?

Read the final report: In-flight break-up involving Cicaré S.A. CH-7BT helicopter, VH-JEW, near Roy Hill Station, Western Australia, on 28 July 2015