A fatal Cessna 172S aircraft accident highlights the dangers of an aircraft stalling and then spinning while conducting turning manoeuvres, particularly at low heights.

A fatal Cessna 172S aircraft accident highlights the dangers of an aircraft stalling and then spinning while conducting turning manoeuvres, particularly at low heights.

On 29 December 2014, a Cessna 172S aircraft departed Cambridge Airport, Tasmania to photograph yachts participating in the 2014 Sydney Hobart race as they made their way around the southern coast of the Tasman Peninsula. On board the aircraft were the pilot and a photographer.

At about 1815 the aircraft commenced low-level photographic runs on yachts to the east of Cape Raoul. Shortly after completing a run on one yacht at a height of about 50 ft, the aircraft entered a steep turn. The aircraft had almost completed a 180° turn when the upper (right) wing dropped sharply while the aircraft’s nose pitched down to almost vertical. The aircraft impacted the water’s surface in an almost vertical nose down attitude with wings about level. Both aircraft occupants were fatally injured, and the aircraft was seriously damaged.

As a result of the steep turn, the aircraft’s upper wing aerodynamically stalled, resulting in a rapid rotation out of the turn. The aircraft’s steep pitch attitude on impact indicated that, because of the stalled upper wing, the aircraft entered a spin. There was insufficient height for the pilot to recover the aircraft. The final turn was not in accordance with the pilot’s training for low-level flight. Cessna identified that any C172 type aircraft that enters a stall/spin condition will require significant height to recover.

The Civil Aviation Safety Authority had issued the operator with a dispensation that permitted low-level flight down to 150 ft above obstacles. Low-level photographic operations on yachts conducted by the operator had been consistently flown at heights down to 50 ft. Although the aircraft was being operated at a height lower than that authorised by the dispensation, that in itself was not likely to have contributed to the accident.

The ATSB examined the role of the operators’ Safety Management System (SMS). While it was not established that the safety risk management processes and practices directly contributed to the occurrence, there were aspects that the operator could consider working towards to more effectively identify all key operational risks.

The operator advised that it has ceased low-level photography flights.

Safety message

Turning manoeuvres at or close to the aircraft’s critical angle of attack, or stall speed, if poorly handled, can result in a stall that will probably result in the aircraft entering a spin. This is particularly true for aircraft under 5,700 kg. The normally benign stalling characteristics of these aircraft types are exacerbated by the spin entry, which results in a steep pitch down and rotation towards the stalled wing. Recovery from this condition will take a considerable amount of altitude, dependant on the speed of response by the pilot and the use of appropriate control inputs.

Read the final report: Collision with terrain Cessna 172, VH-PFT, Maingon Bay (9 km south of Port Arthur), Tasmania, on 29 December 2014

A collision between an aircraft and aerobridge highlights the difficulties in detecting slow aircraft movement and why flight crew should remain aware of this possibility whenever the engines are running.

A collision between an aircraft and aerobridge highlights the difficulties in detecting slow aircraft movement and why flight crew should remain aware of this possibility whenever the engines are running.

On 22 April 2013, the flight crew of a United Airlines Boeing 747-422, flew from Sydney, New South Wales to Melbourne, Victoria. At Melbourne, the crew taxied to gate D5 and stopped, applying the parking brake. Shortly after stopping, the aircraft started to move forward again slowly. The flight crew realised the aircraft was moving and re-applied the brakes. The aircraft’s left wing collided with the aerobridge before the movement had stopped. No one was injured during the occurrence and the aircraft sustained minor damage.

After stopping at the gate, the aircraft parking brake was likely inadvertently released before the nose wheels were chocked and the engines shut down. The flight crew’s attention was inside the cockpit, focused on shutting down the engines. As such they were not actively monitoring aircraft movement, nor was that required at this stage. In addition, the parking guidance system at the gate was set to emergency stop mode by ground personnel when the aircraft first arrived, removing the possibility of an alert for the flight crew that the aircraft had moved. The flight crew became aware of the movement when the captain detected motion through peripheral vision. The very slow acceleration, combined with a lack of visual cues available to the flight crew made it difficult for the crew to detect the movement in time to prevent the collision.

Safety message

This occurrence highlights the importance of flight crew remaining aware of the possibility of aircraft movement whenever the engines are running as aircraft movement, particularly if it is slow, is difficult to detect. Additionally, ground support crew are reminded of the need to leave the parking guidance system in normal mode, unless an emergency stop is required.  

Read the final report: Collision with aerobridge involving Boeing 747-422, N119UA, Melbourne Airport, Victoria, on 22 April 2013

On 24 October 2014, the Melbourne to Sydney XPT service ST24 was approaching Culcairn station when there was a severe vibration.

On 24 October 2014, the Melbourne to Sydney XPT service ST24 was approaching Culcairn station when there was a severe vibration. The driver stopped at the station and upon inspecting the train found that the axle had broken adjacent to the bearing box on the fourth passenger carriage. There were no injuries to passengers or crew. The passengers continued their journey to Sydney on chartered buses.

The ATSB found that the axle bearing had failed and completely seized, probably due to cage failure.

The probable cage failure caused the rollers to misalign and seize. This seizure of the rollers generated friction and excessive amounts of heat into the bearing journal. The heat applied to the bearing journal caused it to go ‘plastic’ and separate from the axle (commonly referred to as a screwed journal). In this case, much of the evidence was either lost or damaged beyond useful examination. Consequently, there was insufficient evidence available to determine why the bearing cage may have failed.

The ATSB also identified that ARTC train control, despite receiving reports of trackside fires, made contact with NSW Trains operations, rather than directly with the driver. It is unlikely that direct communication with the driver of ST24 would have resulted in a different outcome in this case because, by the time the potential cause of fires was known, ST24 was already on its way to Culcairn. However, in some scenarios, communicating directly with the train driver would likely ensure a more timely response to issues that may affect the safety of the network.

ARTC will ensure that all matters relating, or potentially relating to, the safety of a train operating on the network will be advised in the first instance to the driver of the involved train by the relevant Network Control Officer.

Safety message

Any issues with train services that can compromise the integrity and safety of the network must be communicated directly to the train driver. Communicating through a third party can compromise a timely response.

Read the final report: Axle failure on XPT ST24, Culcairn, New South Wales, on 24 October 2014

At about 1901 on 22 August 2014, a V/Line train travelling the Werribee line on the Melbourne Metropolitan Rail Network collided with a stationary Metro Trains Melbourne (MTM) passenger train between Maidstone Street level crossing and Kororoit Creek Road. The MTM train had come to an unintended stop due to a loss of air pressure in its braking system.

At about 1901 on 22 August 2014, a V/Line train travelling the Werribee line on the Melbourne Metropolitan Rail Network collided with a stationary Metro Trains Melbourne (MTM) passenger train between Maidstone Street level crossing and Kororoit Creek Road. The MTM train had come to an unintended stop due to a loss of air pressure in its braking system.

The V/Line train had stopped at an Automatic signal that was indicating a Stop aspect and after a short while proceeded past the stop signal. Trains can proceed past an Automatic signal at Stop under conditions specified by an operating rule. Shortly after passing the signal, the train collided with the rear of the stationary MTM train at 43 km/h. The MTM train was carrying 51 passengers at the time of the collision. The driver and conductor on the V/Line train, the driver of the MTM train and eight passengers on the MTM train sustained minor injuries in the incident.

The ATSB found that the operating rule permitted the V/Line train to proceed past a signal at Stop into a section that was occupied by the MTM train. The V/Line train was operated past the signal at Stop in a manner contrary to the operating rule and proceeded at a speed that reduced the opportunity to observe the train ahead and stop in time. The rule placed reliance on the train driver to provide separation between trains by line-of-sight observation and was not an effective defence against errors.

The ATSB also found that the marker lights on the MTM train (Comeng type) did not meet the requirements of the Australian Standard for Railway Rolling Stock Lighting and Rolling Stock Visibility, AS/RISSB 7531.3:2007 for permissive working. This standard was developed by the Rail Industry Safety Standards Board (RISSB) and although MTM had adopted this Standard, it was not implemented on the Comeng trains in their fleet.

Metro Trains Melbourne has amended the existing procedure in Section 3 Rule 1 of The Book of Rules and Operating Procedures 1994 for permitting trains to pass an uncontrolled, unmonitored signal at Stop. The new amendments incorporate a procedure, which requires train drivers to contact and respond to an automated voicemail facility providing their details, the rail vehicle details and details of the signal at Stop.

Metro Trains Melbourne has advised the ATSB that a modification is being developed to increase the intensity of the marker lights of Comeng trains to a level compliant with the Australian Standard for Railway Rolling Stock Lighting and Rolling Stock Visibility, AS/RISSB 7531.3:2007.

Safety message

The rules pertaining to permissive signalling rely on a train driver to provide separation between trains by line-of-sight observation. In the hierarchy of hazard controls, rule based controls are considered the least effective defence against human error or violations. Train operators should institute additional risk mitigation measures, where safeworking systems allow permissive working.

Read the final report: Collision between V/Line train 8280 and MTM train 6502, Altona, Victoria, on 22 August 2014

Fatigue may have contributed to the first officer not hearing the captain’s ‘gear up’ call.

• Fatigue may have contributed to the first officer not hearing the captain’s ‘gear up’ call.

On the evening of 4 December 2014, a Saab Aircraft Co. 340B aircraft, registered VH-ZRJ and operated by Regional Express, was on a scheduled passenger service from Sydney to Narrandera, New South Wales. After take-off from runway 34 Left the crew inadvertently did not retract the landing gear. The crew later identified this and instinctively retracted the gear whilst the aircraft was above the maximum landing gear retraction speed.

The ATSB found that at the time of the occurrence the first officer (FO) was experiencing a level of fatigue that affected performance. However, the FO’s ability to self-assess their level of fatigue was impeded by a lack of training and objective tools to determine their suitability to operate.

The ATSB also found that the FO did not recall hearing the captain’s ‘gear up’ call, which meant that the gear was inadvertently not retracted. The factors that influenced this omission and its non‑detection included both crew focusing on departure procedures and the local weather, and the crew likely expecting that the landing gear was retracted as normal.

The crew detected the error when conducting the climb checklist. As this checklist was designed to confirm the configuration of the aircraft, the time that it was conducted coincided with a time when the aircraft’s speed was above the maximum gear retraction speed. Therefore, there was an increased risk that crew would react to the unexpected gear position before slowing the aircraft.

In March 2013, the Civil Aviation Safety Authority released new rules on fatigue management for flight crew. At the time of the occurrence, air operators that already held, or had applied for an air operator’s certificate after April 2013, had until April 2016 to transition to the new fatigue management rules. Consistent with this timeline, Regional Express was planning for their transition to meet those requirements at the time of the occurrence. In November 2015, this deadline was extended by the Civil Aviation Safety Authority to May 2017.

Safety message

This occurrence demonstrates some of the factors that increase the risk of making and not detecting errors of omission, particularly actions prompted by verbal cues. The use of a checklist helps identify errors, but they are most effective in this regard, if they are timed to be conducted before approaching aircraft limits.

Further, while this occurrence highlights the difficulties associated with assessing fatigue, operators and crew share responsibility for managing the risk of fatigue. Operators can reduce fatigue risk by providing crew with adequate rest opportunity, comprehensive training in fatigue management, and tools designed to support objective self-assessment of their alertness. Crew can then use the knowledge and tools to help identify when fatigue is present and may affect safety.

Read the final report: Landing gear overspeed involving a Saab 340B, VH-ZRJ, near Sydney Airport, New South Wales, on 4 December 2014

While repositioning, the pilot commenced lifting this Bell 206L-1 helicopter into a hover from a temporary helipad. It started rolling about the right skid until the main rotor blades struck the ground.

While repositioning, the pilot commenced lifting this Bell 206L-1 helicopter into a hover from a temporary helipad. It started rolling about the right skid until the main rotor blades struck the ground.

On 2 November 2013, the pilot of a Bell 206L-1 helicopter, registered VH-VDZ, was conducting passenger-carrying charter operations between Olympic Park oval and Flemington Racecourse, Melbourne, Victoria. At about 1830 Eastern Daylight-saving Time, the pilot prepared to reposition the helicopter from one of the temporary helipads at Olympic Park. There were no passengers on board.

As the pilot lifted the helicopter into a hover it started rolling about the right skid, which was in contact with the ground. The helicopter rapidly rolled further right until the main rotor blades struck the ground. A large amount of main rotor and other high energy debris was released from the helicopter and impacted a nearby marquee, a number of vehicles and a helicopter on an adjacent helipad. The pilot sustained minor injuries.

The ATSB found that the pilot did not identify and react to the helicopter’s right-skid low attitude in sufficient time to prevent the helicopter rolling over. In addition, an unsecured ballast bag was positioned on the left front floor of the helicopter, increasing the risk of injury to occupants. Further, the helicopter’s dual flight controls were removed to facilitate the flights. The person who removed the controls did not have the training or authorisation to conduct the maintenance procedure. The left cyclic stub cover was not installed, leaving the stub exposed. This resulted in the potential for the ballast bag to inhibit movement of the pilot’s cyclic control due to fouling of the left cyclic stub.

The ATSB identified safety issues relating to the availability of first aid and emergency response equipment at the oval and the proximity of the helipads to the perimeter fence and public access areas. Each increased the risk of injury to bystanders in the event of an accident.

For subsequent operations at the Olympic Park oval for the remainder of the event, the charterer positioned firefighting equipment at each helipad and first aid equipment was made available nearby. In addition, the helipads were repositioned further from the passenger marquee, and passengers were not loaded or unloaded if helicopters were in the process of landing or taking-off from adjacent helipads. Operations at the Olympic Park oval ceased following the 2013 carnival.

Safety message

This accident highlights the importance of coordinated control inputs by pilots during lift-off to control any roll, and if necessary smoothly lowering the collective in coordination with cyclic input to re‑establish the helicopter’s weight evenly on the ground before any roll becomes excessive. The importance of properly securing any equipment, particularly if stowed in aircraft cockpits, and of the correct removal and re-fitting of dual flight controls to prevent any obstruction or fouling of the controls is emphasised.

In addition, this accident is a reminder of the risks involved when operating helicopters in public areas. Although the likelihood of a helicopter accident on the ground that results in injuries was found by the ATSB to be low, in the event of an accident, high energy rotor and other debris can travel large distances. Where possible, operators should consider larger distances around helicopter landing areas, in particular when operating close to public areas.

Read the final report: Collision with terrain involving Bell 206L helicopter, VH-VDZ, at Melbourne, Victoria, on 2 November 2013

A wheel failure that led to a train derailment, damaging 590 m of track, likely originated from a crack on the tread surface, the ATSB has found.

A wheel failure that led to a train derailment, damaging 590 m of track, likely originated from a crack on the tread surface, the ATSB has found.

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

What the ATSB found

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

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

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

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

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

Safety message

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

Read the final report: Derailment of freight train MB520, Pangela, New South Wales, on 28 August 2015

The ATSB Commission today welcomes Greg Hood who begins his five-year appointment as the second Chief Commissioner of the Australian Transport Safety Bureau.    

Greg has more than 35 years’ experience in the transport industry, beginning his career as an air traffic controller in the Royal Australian Air Force (RAAF). Greg has since had a wide range of operational, training and management roles across the civil aviation industry. Most recently, Greg served in senior roles in Airservices Australia and the Civil Aviation Safety Authority.

As well as being a glider and powered aircraft pilot, Greg is involved with a number of aviation bodies. He is a Fellow of the Royal Aeronautical Society, a Freeman in the Honourable Company of Air Pilots, and a Life Member of the Qantas Founders Museum. Before joining the ATSB, Greg was a Board Member of Safeskies Australia and Vice-Chair of the steering committee for the Civil Air Navigation Services Organisation’s (CANSO’s) Operations Standing Committee.

The Commission looks forward to the extensive experience and expertise Greg will bring to the ATSB, and transport safety investigations.

The Commission sincerely thanks previous Chief Commissioner Martin Dolan for his valuable leadership over the past seven years. Martin has overseen a number of major ATSB investigations that resulted in significant improvements to transport safety. These include the ATSB’s investigation into:

• the uncontained engine failure of a Qantas A380 aircraft over Batam Island in 2010, which resulted in international safety improvements to Rolls-Royce engines and airframe certification standards for all aircraft
• safety issues involving Queensland coastal pilotage, resulting in regulatory and operational improvements to pilotage operations
• Sydney to Melbourne railway line that examined the safety of the rail track along with a systemic review of the track’s safety systems
• the in-flight upset of a Qantas A330 in Western Australia that uncovered critical lessons for manufactures of complex safety systems.

Martin has strengthened the ATSB’s position as a national and international leader in transport safety. He played a critical role in reforming Australia’s rail safety investigations under a single national jurisdiction and oversaw the unprecedented search for missing Malaysia Airlines flight MH370.

The Commission wishes Martin the best in his retirement and looks forward to building on his success under Greg’s leadership.  

As a result of the investigation into a Virgin Australia Regional Airlines flight sustaining a pitch disconnect while on descent into Sydney, the ATSB has identified a safety issue that needed to be highlighted before this investigation is completed.

As a result of the investigation into a Virgin Australia Regional Airlines flight sustaining a pitch disconnect while on descent into Sydney, the ATSB has identified a safety issue that needed to be highlighted before this investigation is completed.

• Inadvertent application of opposing pitch control inputs by flight crew can activate the pitch uncoupling mechanism which, in certain high-energy situations, can result in catastrophic damage to the aircraft structure before crews are able to react.

This interim report provides only the factual information and analysis associated with the identified safety issue and complements information already provided on an update on the ATSB website on 10 June 2014. New evidence may become available as the investigation progresses that will enhance the ATSB’s understanding of the occurrence.

Read the interim report: In-flight upset, inadvertent pitch disconnect, and continued operation with serious damage involving ATR 72 aircraft, VH-FVR, 47 km west-south-west of Sydney Airport, New South Wales, on 20 February 2014