Safety summary

What happened

In the early hours of 14 July 2015, the offshore support vessel (OSV) Skandi Pacific was loading cargo containers from the semi-submersible oil rig Atwood Osprey at its offshore location, about 90 miles north-west off Dampier. Shortly after 0505, cargo transfer was stopped due to worsening weather conditions. Skandi Pacific was moved 30 m away from the rig with the rough seas still on its port quarter. Two crewmembers then began securing cargo on the vessel’s aft deck.

While securing the cargo, the crewmembers slackened the securing chain they had used to secure the containers on the starboard side to better secure the entire stow. At about 0523, two large waves came over Skandi Pacific’s open stern, shifting the unsecured containers forward. One of the crewmembers was trapped between the moving containers, chains and a skip and suffered fatal crush injuries.

What the ATSB found

The ATSB investigation found that the risks associated with securing the cargo in the prevailing weather conditions on 14 July had not been adequately assessed. The fatally injured man was standing in a dangerous location near the unsecured cargo containers when they shifted.

The investigation identified that Skandi Pacific’s safety management system (SMS) procedures for working/securing cargo on deck in poor weather were inadequate with no clearly defined weather limits. Further, there were no clearly defined limits for excessive water on deck that necessitated stopping operations, leaving individuals to make difficult, and necessarily subjective, decisions about whether or not to stop work.

The ATSB also found that Skandi Pacific’s managers had not adequately assessed the inherent high risks associated with seas coming over the vessel’s open stern when work, including cargo handling operations, was being undertaken on its aft deck.

What's been done as a result

Proactive safety action by Skandi Pacific’s managers to avoid a similar accident includes improved cargo handling practices across its OSV fleet. Amongst these measures are updated procedures for working in adverse weather and cargo loading, including specific weather condition limits. In addition, existing risk assessments for offloading deck cargo at installations have been updated to include a section on risks associated with securing cargo.

The safety action taken by the vessel’s managers has adequately addressed the safety issues related to cargo handling/securing in adverse weather. The action taken has partially addressed the safety issue with regard to open stern vessels.

Therefore, the ATSB has issued a safety recommendation to the vessel’s managers to undertake further work to better address the risks associated with the use of vessels with open sterns. The ATSB has also issued a safety advisory notice to shipmasters, owners, and operators of OSV’s to highlight the risks posed by the open stern vessels to the industry more broadly.

Safety message

Offshore support vessel operations are inherently high risk because they often occur in exposed locations in a particularly dynamic environment. Multiple factors, including the weather conditions, schedule requirements, time of day, limited crew numbers, restrictions due to vessel design and systems, amongst others, add complexity to operations. Therefore, risk assessments are critical, with the weather and its impact on factors, such as an open stern, invariably a vital consideration.

Safety issues and actions

The safety issues identified during this investigation are listed in the Findings and Safety issues and actions sections of this report. The Australian Transport Safety Bureau (ATSB) expects that all safety issues identified by the investigation should be addressed by the relevant organisation(s). In addressing those issues, the ATSB prefers to encourage relevant organisation(s) to proactively initiate safety action, rather than to issue formal safety recommendations or safety advisory notices.

All of the directly involved parties were provided with a draft report and invited to provide submissions. As part of that process, each organisation was asked to communicate what safety actions, if any, they had carried out or were planning to carry out in relation to each safety issue relevant to their organisation.

Where relevant, safety issues and actions will be updated on the ATSB website as information comes to hand. The initial public version of these safety issues and actions are in PDF on the ATSB website.

Cargo handling procedures

Number:	MO-2015-005-SI-01
Issue owner:	DOF Management, Norway (DOF Management)
Operation affected:	Marine: Shipboard operations
Who it affects:	All owners and operators of offshore support vessels

Safety issue description:

Skandi Pacific’s safety management system (SMS) procedures for cargo handling in adverse weather conditions were inadequate. Clearly defined weather limits when cargo handling operations could be undertaken and trigger points for suspending operations were not defined, including limits for excessive water on deck.

Proactive safety action taken by DOF Management

Action number: MO-2015-005-NSA-003

Following the accident, DOF management submitted a ‘safety flash’ to the offshore industry organisation, International Marine Contractors Association. The safety flash summarised key safety matters and the accident, allowing wider dissemination of lessons learned to the industry. The company also undertook to review the adverse weather working guideline and the cargo loading procedure to include cargo lashing arrangements, and risk assessment for securing cargo.

Subsequently, DOF Management advised the ATSB that the existing working in adverse weather procedure had been reviewed and updated. The procedure now includes weather limits related to specific wind speeds, sea state, tidal streams, visibility and vessel movement. The precautions to be taken are directly related to each of the trigger points. In addition, working parameters for vessels with open sterns include a trigger point in the event that water is shipped on deck over the stern. The master is to be informed, who is then required to have a risk assessment conducted.

Current status of the safety issue

Issue status: Adequately addressed

Justification: The revised procedures for working in adverse weather and cargo handling, and the additional safety action taken has adequately addressed the safety issue.

Cargo securing procedures

Number:	MO-2015-005-SI-02
Issue owner:	DOF Management, Norway
Operation affected:	Marine: Shipboard operations
Who it affects:	All owners and operators of offshore support vessels

Safety issue description:

Skandi Pacific’s safety management system (SMS) procedures for cargo securing were inadequate. There was no guidance for methods of securing cargo in adverse weather conditions.

Proactive safety action taken by DOF Management

Action number: MO-2015-005-NSA-002

Following the accident, DOF management submitted a ‘safety flash’ to the offshore industry organisation, International Marine Contractors Association. The safety flash summarised key safety matters and the accident, allowing wider dissemination of lessons learned to the industry. The company also undertook to review and update the cargo securing procedure and risk assessment to include the requirement for a lashing plan and load sequence planning with rig prior to entry of 500 m zone.

Subsequently, DOF Management advised the ATSB that its existing cargo loading procedure and risk assessment had been revised to include further clarification surrounding cargo lashing and hazards of shifting cargo. The revised procedure contains trigger points for assessing further operation when there is:

• water on deck over the stern
• an unexpected deterioration in weather
• an unfavourable change of the vessel position/heading.

Additionally, when offloading and backloading cargo alongside offshore installations, the risk assessment for securing cargo is to be reviewed and updated to ensure all hazards of shifting cargo are identified and addressed.

Further, a simultaneous operations (SIMOPS) procedure for combined rig and vessel cargo loading operations has been developed and implemented. The SIMOPS procedure is in addition to the procedures for working in adverse weather and cargo loading.

Current status of the safety issue

Issue status: Adequately addressed

Justification: The revised procedures and risk assessments for cargo handling and securing, and the additional safety action taken has adequately addressed the safety issue.

Open stern offshore support vessels

Number:	MO-2015-005-SI-03
Issue owner:	DOF Management, Norway
Operation affected:	Marine: Shipboard operations
Who it affects:	All owners and operators of offshore support vessels

Safety issue description:

Skandi Pacific’s managers had not adequately assessed the risks associated with working on the aft deck of vessels with open sterns, including consideration of engineering controls to minimise water being shipped on the aft deck.

Response to safety issue by DOF Management

Action number: MO-2015-005-NSA-004

Following the accident, DOF management submitted a ‘safety flash’ to the offshore industry organisation, International Marine Contractors Association. The safety flash summarised key safety matters and the accident, allowing wider dissemination of lessons learned to the industry. The company also undertook to conduct of a risk assessment for anchor handling tug supply (AHTS) vessels conducting cargo operations. The risk assessment was to include considering engineering controls to minimise excessive water on the vessel back deck (for example, stern door or other vessel type).

Subsequently, DOF Management advised the ATSB that the existing risk assessment for offloading deck cargo at installation had been reviewed and updated to include a section regarding risks associated with securing cargo. The company indicated that it had assessed and mitigated risks associated with vessels with open stern.

ATSB comment/action in response

The ATSB acknowledges the proactive safety taken by DOF Management. However, the ATSB considers further action is necessary to adequately address the risks associated with the use of vessels with open sterns, including the engineering controls to minimise shipping seas on the aft deck proposed in the company’s response. Therefore, the ATSB has issued the following recommendation and safety advisory notice.

ATSB safety recommendation to DOF Management

Action number: MO-2015-005-SR-006

Action status: Released

The Australian Transport Safety Bureau recommends that DOF Management take further action to adequately address the safety issue concerning the use of vessels with open sterns.

Current status of the safety issue

Issue status: Partially addressed

Justification: Further action by DOF Management to adequately address the safety issue, including the company’s proposal to consider engineering controls to minimise shipping seas on the aft deck of open stern vessels, is considered necessary.

ATSB safety advisory notice to masters, owners and operators of offshore support vessels

Action number: MO-2015-005-SAN-005

Action status: Closed

The Australian Transport Safety Bureau advises the masters, owners and operators of all offshore support vessels to ensure that the risks associated with working on the aft deck of vessels with open sterns are adequately assessed.

Additional safety action

Whether or not the ATSB identifies safety issues in the course of an investigation, relevant organisations may proactively initiate safety action in order to reduce their safety risk. The ATSB has been advised of the following proactive safety action in response to this occurrence.

DOF management advised the ATSB that a marine risk awareness presentation titled SAFE the RITE WAY and a safety handbook have been developed and implemented. A 'lessons learned' communication plan from this accident are included in the SAFE the RIGHT WAY induction and presentation. Presentations have been delivered both externally to industry partners and forums and internally via mandatory DOF induction training.

Context

Skandi Pacific

At the time of the accident, the anchor handling tug supply (AHTS) vessel, Skandi Pacific, was registered in the Bahamas, classed with Det Norske Veritas (DNV) and managed by DOF Management, Norway. The vessel was under charter to Chevron Australia to facilitate support operations for the semi-submersible oil rig, Atwood Osprey.

As an offshore support vessel (OSV) Skandi Pacific was designed for offshore operations including anchor handling and towing, and had a multi-national crew of 12, including the master. The master had 20 years of seagoing experience, including 5 years as master on OSVs. He had been assigned to the vessel for the past 2½ years and had joined it about 2 weeks before the accident.

The chief mate had 14 years of seagoing experience, including 7 years on offshore support vessels. He had been chief mate on Skandi Pacific for 1½ years as chief mate and had joined about 2 weeks before the accident.

The Integrated Ratings (IR) on deck at the time of the accident were suitably qualified in their respective ranks. Both IRs had experience at this rank on board OSVs and had joined Skandi Pacific about 2 weeks before the accident.

DP system

A computerised Dynamic Positioning (DP) system uses the vessel’s thrusters and propellers to control its position and heading. The DP system automatically adjusts the propulsion units to counteract the environmental forces (Figure 6) to keep the vessel on location at, or very near to a specified position.

Figure 6: Vesselpropulsion, thrusters, movement and external forces

Source: DOF Management (annotated by ATSB)

Accurate measurement of the vessel’s position at any point in time is necessary for precise DP. Additionally, as the vessel is subject to wind, wave and current forces, these forces also need to be accurately measured by the DP system. The system then controls the vessel’s motion in the three horizontal degrees of freedom:

• surge^[12]
• sway^[13]
• yaw.^[14]

The position reference systems consist of DGPS^[15], RADius^[16] and Fanbeam,^[17] of which all three reference systems are required for DP class 2^[18] operations.

Skandi Pacific was equipped with two stern thrusters, two bow thrusters and two controllable pitch propellers, designed to comply with a DP equipment class two system. The vessel’s position could also be maintained manually by using a single joystick to control all thrusters.

When the vessel was operating in DP mode, its status could be one of the following:

• Green status: normal operation indicating the position and heading were within predetermined limits.
• Yellow status: degraded DP control indicating position keeping was deteriorating and/or unstable (moving 2 m from the set position) and weather conditions becoming unsuitable for DP operation (the DP operator or DPO,^[19] master and rig supervisor should then discuss continued operations).
• Red status: indicating a DP emergency triggered by either by a system failure or external condition, preventing the vessel maintaining its position within 4 m from the set position.

Annual DP trial programme

Annual DP trials are a thorough test of a DP system to verify its capability and performance and to confirm it has been maintained in accordance with international requirements. Further, all major DP systems and sub-systems are tested to determine the ability of the vessel to maintain position after single system failures,^[20] associated with the assigned equipment class.

These tests confirm that the ‘failure modes and effects analysis’^[21] conducted during the design process of the vessel is still valid. Any new equipment or system upgrades are incorporated in all trials to ensure they react as intended.

DP capability plot

DP capability defines a vessel’s ability to remain in position under given environmental and operational conditions. The capability plots (Figure 7) are calculated for normal operation and for DP system failures, such as a loss of thruster, including worst case failures.

These plots are not of actual performance, but are based on calculations and provided by the manufacturer of the DP system. The calculated DP capabilities of the vessel can be used to determine if the vessel will remain in position during DP operations in the prevailing or forecast weather conditions.

Skandi Pacific’s DP capability plots (Figure 7) show the ‘normal operations’ and ‘single bow thruster failure’. The plots show the limiting wind speed 360 degree envelopes (blue line), where each point on the envelope represents the wind speed at which it is calculated that the vessel will be unable to maintain position in DP mode. With a single bow thruster failure, the vessel had reduced capability when winds exceeded 60 knots.

Figure 7: Skandi Pacific's DP capability plots

Source: Skandi Pacific (annotations by ATSB)

DP system check

Offshore facilities are protected by the establishment of an exclusion safety zone^[22] around the structure and entry into the exclusion safety zone is controlled by the facility.

Prior to entering the exclusion zone at any facility, all vessels are required to complete a pre-entry checklist. The purpose is to ensure satisfactory operation of the vessel’s DP system, including full functional checks of the operation of the thrusters, power generation, automatic DP and joystick/manual control.

Additionally, when departing the facility, the vessel is to be manoeuvred well clear of the facility before changing operating modes. The Guidelines for Offshore Marine Operations (G-OMO)^[23] recommend that this distance is usually between 1½ to 2½ vessel lengths, depending on the drift conditions.

Operational risk management

The DOF Management operational risk management procedures are mainly based on best practice and the G-OMO. These procedures included the following guidance.

Risk assessment

Risk Assessments (RA) are used to identify and then mitigate risks to an acceptable level. If the risks cannot be mitigated to an acceptable level, the work should not proceed.

The RAs on board Skandi Pacific included details of the task, the team members, activity description, identified hazards, the effects of those hazards, existing controls and additional control measures.

Toolbox talks

A toolbox talk (TBT) is a meeting of the personnel involved in an imminent task to review the task, individual responsibilities, equipment required, competency of the individuals, hazards, and any RAs in place.

On board Skandi Pacific, all personnel involved in cargo handling operations attended TBTs. The objective was to communicate the RA and to capture any additional controls not already identified. This included (but was not limited to):

• individual roles
• tools, methods and procedures to be used
• a review of the RA
• promote the ‘stop the job’^[24] culture.

Management of change

The company had a management of change (MOC) process in place for all tasks. This process was used when unexpected changes in circumstance occurred before or during the course of the task. It was then used to identify the change type, details, criticality and what action was required now that the change had occurred. The task would not continue until the implications of that change were reviewed. If appropriate, the RA would be reviewed before resumption of the task and a TBT carried out. For example, the loss of the use of a bow thruster on board Skandi Pacific changed the operational capability of the vessel. Therefore the MOC process was used to define and assess subsequent operational limitations.

Cargo stowage and securing

There are many sources of relevant guidance for cargo handling on board OSVs. The International Maritime Organization’s (IMO) Resolution A.863(20)^[25] states the following for OSVs with an open stern:

vessels are provided with instructions to counter dangerous situations if cargoes with a tendency to float and/or with low friction coefficients are stowed on the exposed deck

the number of cargo handlers should be sufficient for safe and effective cargo operations

the crew of OSVs should be adequately trained

safe havens and escape routes for personnel from the cargo deck should be properly marked and kept clear at all times. A crash barrier, fitted along each side of the deck, could be one method of achieving a safe haven.

Further guidance is contained in Regulation 5, Chapter VI, SOLAS^[26] (Stowage and securing) which specifically references all cargoes, cargo units and cargo transport units shall be loaded, stowed and secured in accordance with the Cargo Securing Manual (CSM).

The Cargo Securing Manual^[27] (CSM) is to include information on a number of pre-identified items:

details of fixed securing arrangements and their locations

examples of correct application of portable securing gear on various cargo units, carried on the vessel.

Skandi Pacific’s CSM contained the above procedures for cargo handling alongside installations and included the following guidance for open stern AHTS vessels:

Open stern anchor handling vessels require special care, especially with regards to freeboard. Consideration should be given to the open stern being physically barriered. Use RA and TBT to minimise crew or cargo exposure to elements, particularly when working with the stern towards the weather.

Additionally, the IMO Resolution A.717(17), Code of Safe Practice for Cargo Stowage and Securing, states:

The proper stowage and securing of cargoes is of the utmost importance for the safety of life at sea. Improper stowage and securing of cargoes has resulted in numerous serious vessel casualties and caused injury and loss of life, not only at sea but also during loading and discharge.

Maritime boundaries

In 1994, the Australia government ratified the United Nations Convention on the Law of the Sea (UNCLOS) and became legally bound to its provisions. As such, Australia is bound to follow UNCLOS rules for maritime boundaries, access to the various marine zones and managing the resources and activities within those boundaries.

Figure 8: Maritime boundaries off the North West Shelf, Western Australia

Source: Geoscience Australia (annotated by ATSB)

To determine the maritime boundaries (Figure 8) requires the delineation of the Territorial Sea Baseline^[28] (TSB). The TSB is the line from which the outer limits of a number of maritime zones are calculated and include the:

• 3 nautical mile limit of the coastal waters^[29]
• 12 nautical mile limit of the territorial sea^[30]
• 24 nautical mile limit of the contiguous zone^[31]
• 200 nautical mile limit of the Australian Exclusive Economic Zone.^[32]

Jurisdiction

The Offshore Constitutional Settlement (OCS) is an agreement between the Commonwealth and the States, which provides the basis for an agreed division of powers in relation to coastal waters and other matters. These include the regulation of shipping and navigation, offshore^[33] petroleum exploration, crimes at sea, and fisheries.

National Offshore Petroleum Safety and Environmental Management Authority

The National Offshore Petroleum Safety and Environmental Management Authority’s (NOPSEMA) functions and powers are derived from the Offshore Petroleum and Greenhouse Gas Storage Act 2006 (OPGGS Act) and associated regulations. The OPGGS Act provides that NOPSEMA is charged with regulating health and safety, well integrity and environmental management for all offshore petroleum facilities and activities in Commonwealth waters.^[34] Additionally, it has similar functions where State and Territory powers to regulate have been transferred, covering the area within the first three nautical miles for coastal waters.

The Australian Maritime Safety Authority

The Australian Maritime Safety Authority (AMSA) is charged with the responsibility for ensuring the safety of Australian flagged vessels and foreign flagged vessels in Australian ports and waters, and the seafarers on board. International and national conventions and regulatory frameworks provide the standards enforced by AMSA to achieve safety outcomes. 

According to AMSA, it delivers necessary safety outcomes through inspections such as those under Port State Control, flag State requirements, Cargo, Maritime Labour Convention, and Occupational Health and Safety (OHS) when the ship is in port.

Trained AMSA OHS inspectors perform investigations of accidents and dangerous occurrences on ‘prescribed ships’^[35]:

• in an Australian port
• entering or leaving an Australian port
• in the internal and territorial waters of Australia.

Skandi Pacific was not covered under the above requirements and, hence, Australian OHS legislation did not apply to the vessel.

Memorandum of Understanding between AMSA and NOPSEMA

The Memorandum of Understanding (MoU) between the two authorities provides for the cooperation of both parties in the administration of their respective commitments including audits, inspections and accident investigations of offshore facilities. It delivers a consistent and comprehensive regulatory regime in offshore waters and avoids duplication in respect of vessels and facilities where the two organisations have regulatory obligations. The MoU was last revised in 2013, when AMSA and NOPSEMA agreed to further joint inspections of floating facilities.

At the time of the accident, Skandi Pacific was not engaged in cargo handling operations with Atwood Osprey. The vessel was also outside the territorial waters of Australia. Its location and status meant that it was outside the jurisdiction of both NOPSEMA and AMSA.

Safety investigations

The IMO’s Casualty Investigation Code is mandatory under SOLAS and requires the flag State^[36] of a vessel to conduct a marine safety investigation into every ‘very serious marine casualty’.^[37] The Bahamas, as the flag State of Skandi Pacific was obliged to investigate the fatal accident on 14 July. The Bahamas Maritime Authority commenced a safety investigation under their national legislation.

The ATSB, as a substantially interested State,^[38] also commenced a safety investigation.

Similar past accidents

The ATSB’s predecessor, the Marine Incident Investigation Unit (MIIU), investigated a similar fatal accident on board an OSV in 1995.

Shelf Supporter was a 1985-built OSV equipped with a DP system. The vessel had a large, clear aft deck that enabled it to carry stores and equipment to/from offshore facilities. It operated off the north-west coast of Australia.

At about 0550 on 29 December 1995, Shelf Supporter’s master manoeuvred the OSV to approach an offshore platform’s crane position with its bow in (that is, stern to sea). It had cargo on the aft deck, which had been secured by the vessel’s crewmembers using tugger wires and winches.

Shortly after 0600, two crewmembers went out to the aft deck to prepare for unloading cargo. They released the tugger wires and re-spooled the starboard wire onto the winch drum. However, before they could re-spool the port wire, the vessel arrived under the crane and its lifting hook was lowered just above their heads. They left the port wire flaked on deck, and hooked on the first lift.

On the bridge, the master was maintaining the vessel’s position and saw a wave breaking over the stern. He broadcast a warning to the two men on deck. As the water ran up the deck, he saw one of the men just forward of a skip. He then saw the skip move forward and crush the man against another skip.

The following summary of some of the MIIU’s findings is particularly relevant:

• OSVs frequently work in moderate and even rough seas. Their design with a long low aft deck, generally with no protective stern bulwark makes seas breaking over the stern common place.
• Sea conditions at the time of the accident were not such as to warrant cancelling operations.
• Although a warning may be called out to crewmembers on deck, they have little time to react. If a sea breaks over the stern and they do not see it approaching, their reactions must be instinctive.
• The securing of cargo in block stows with the tugger wires is common practice in the offshore industry. It is simple and easy to set up and quick to release. However, it has a big disadvantage because once removed, all of the deck cargo is unsecured until discharged.

In June 2016, the International Marine Contractors Association (IMCA)^[39] promulgated details of a recent incident involving cargo shift on an OSV’s aft deck in heavy weather while alongside a platform.

The OSV was engaged in cargo handling operations with its starboard quarter to the weather when it experienced a sudden and unexpected squall. A large wave was shipped and flooded the aft deck. The water shifted one container and turned another one over. The backloaded containers had not yet been secured due to on-going backloading. Fortunately, no one was injured.

The lessons learned included:

• The risk of abnormal waves should be taken into consideration in risk assessments and tool box talks for work, particularly when the vessel is positioned stern to the weather
• Greater emphasis should be placed on the ‘stop work policy’ – anyone should be able to stop the job, any time, when in doubt
• A new and higher bulwark to be fitted to the vessel and other similar vessels.

__________

12. The bodily motion of a ship in a seaway forward and back along the longitudinal axis.
13. The side-to-side bodily motion of a ship in a seaway, independently of rolling, caused by a uniform pressure being exerted all along one side of the hull.
14. The horizontal oscillation of a ship about a vertical axis approximately through its centre of gravity.
15. Differential Global Positioning System.
16. RADius is a short distance reference system consisting of transponders installed as targets, in this case on the platform and sensors on the OSV vessel.
17. Fanbeam is a short range laser scanning radar system.
18. DP equipment Class 2 has redundancy so that no single fault in an active system will cause the system to fail. Loss of position should not occur from a single fault of an active component or system such as generators, thruster, switchboards, remote controlled valves etc.
19. The designated watchkeeping officer responsible for managing the dynamic positioning of the vessel.
20. Single failure criteria include any active component or system (such as generators, thrusters, switchboards or remote controlled valves), together with any normally static component (such as, cables, pipelines or manual valves) that cannot be shown to have adequate protection from damage or have proven reliability.
21. A systematic analysis of the systems to demonstrate that no single system failure will cause an undesired event.
22. Established within a radius extending to a distance determined by the relevant legislations beyond the outline of any installation, excluding submarine pipelines (NOPSEMA).
23. The G-OMO provides guidance in the best practices which should be adopted to ensure the safety of personnel on board all vessels servicing and supporting offshore facilities, and to reduce the risks associated with such operations.
24. Stopping The Job is one in which everyone has the right to stop the job, the duty to stop the job and the moral responsibility to stop the job.
25. The Code of Safe Practice for the Carriage of Cargoes and Persons by Offshore Support Vessels (OSV Code).
26. The International Convention for the Safety of Life at Sea, 1974, as amended.
27. IMO Resolution A.489(XII), adopted on 19 November 1981, Safe Stowage And Securing Of Cargo Units And Other Entities In Ships Other Than Cellular Container Ships Cargo Securing Manual.
28. The TSB corresponds with the low water line along the coast, including the coasts of islands. The baseline can be drawn around low tide elevations which are defined as naturally formed areas of land surrounded by and above water at low tide but submerged at high tide, provided they are wholly or partly within 12 nautical miles of the coast. For Australian purposes, the baseline corresponds to the level of Lowest Astronomical Tide (LAT)
29. Coastal Waters is a belt of water between the limits of the Australian States and the Northern Territory and a line 3 nm seaward of the territorial sea baseline. Jurisdiction over the water column and the subjacent seabed is vested in the adjacent State or Territory as if the area formed part of that State or Territory.
30. The Territorial Sea is a belt of water not exceeding 12 nm in width measured from the territorial sea baseline. The major limitation on Australia's exercise of sovereignty in the territorial sea is the right of innocent passage for foreign ships.
31. The Contiguous Zone is a belt of water contiguous to the territorial sea, the outer limit of which does not exceed 24 nm from the territorial sea baseline.
32. The Exclusive Economic Zone (EEZ) is an area beyond and adjacent to the territorial sea. The outer limit of the EEZ cannot exceed 200 nm from the baseline.
33. An offshore area starts 3 nm from the TSB from which the breadth of the territorial sea is measured and extends seaward to the outer limits of the continental shelf.
34. The Commonwealth marine area is any part of the sea, including the waters, seabed, and airspace, within Australia’s exclusive economic zone and/or over the continental shelf of Australia, that is not State or Northern Territory waters.
35. A prescribed ship is a ship registered in Australia, a ship engaged in coastal trading, a ship on which the majority of crewmembers are residents of Australia and which are operated by persons or firms which have their principal place of business in Australia or a ship declared by the Minister to be a prescribed ship.
36. Flag State means a State whose flag a ship is entitled to fly.
37. A very serious marine casualty means a marine casualty involving the total loss of the ship or a death or severe damage to the environment.
38. A substantially interested State means a State where, as a result of a marine casualty, nationals of that State lost their lives or received serious injuries.
39. The IMCA is a trade association representing companies and organisations engaged in delivering offshore, marine and underwater solutions.

Findings

From the evidence available, the following findings are made with respect to the crewmember fatality on board Skandi Pacific, at sea on 14 July, 2015. These findings should not be read as apportioning blame or liability to any particular organisation or individual.

Safety issues, or system problems, are highlighted in bold to emphasise their importance. A safety issue is an event or condition that increases safety risk and (a) can reasonably be regarded as having the potential to adversely affect the safety of future operations, and (b) is a characteristic of an organisation or a system, rather than a characteristic of a specific individual, or characteristic of an operating environment at a specific point in time.

Contributing factors

• Skandi Pacific’s officer of the watch suspended cargo handling operations due to adverse weather conditions, including water on deck, and moved the vessel off the oil rig to secure cargo on its aft deck.
• The task of securing the cargo after operations were stopped and the options to safely complete it were not adequately assessed.
• The vessel remained on the same heading in dynamic positioning (DP) mode because the officer of the watch considered this the safest option instead of others, such as running with the weather.
• The master was not called and remained unaware of the situation and, hence, did not get the opportunity to consider safer options for securing cargo, such as running with the weather or changing the vessel’s heading.
• Working on deck when water was being shipped was contrary to the master’s instructions.
• In an attempt to secure cargo effectively, the vessel’s crewmembers tensioned down the primary securing chain, which left the entire block of cargo unsecured.
• The crewmembers on deck carried out their plans in isolation without the active involvement of the officers on watch.
• A crewmember was standing in a position of danger when attempting to fasten a securing chain forward of a block of cargo.
• A large wave came over the vessel’s stern and shifted the block of cargo, which crushed the crewmember, fatally injuring him.
• While it was required to have two men on the working deck, at the time of the accident, the men on deck were separated for about 30 seconds, after one of them went forward to the deck locker to get a shackle to resecure the cargo.
• Skandi Pacific’s safety management system (SMS) procedures for cargo handling in adverse weather conditions were inadequate.Clearly defined weather limits when cargo handling operations could be undertaken and trigger points for suspending operations were not defined, including limits for excessive water on deck. [Safety issue]
• Skandi Pacific’s SMS procedures for cargo securing were inadequate. There was no guidance for methods of securing cargo in adverse weather conditions. [Safety issue]

Other factors that increased risk

• Skandi Pacific’s managers had not adequately assessed the risks associated with working on the aft deck of vessels with open sterns, including consideration of engineering controls to minimise water being shipped on the aft deck. [Safety issue]
• At the time of the accident, the officer who was solely in charge of the DP system was performing the tasks of both the DP officer and the communications/monitoring officer, contrary to the risk assessment for cargo transfers. The other officer on the bridge was occupied entering the vessel’s next passage plan into the electronic chart display and information system.
• During the operations leading up to the accident, the officers on the bridge did not keep the men on the aft deck in sight at all times as required by the vessel’s cargo handling procedures. Further, the radio communication between the men on deck and the officers was inadequate.

Other findings

• While one of Skandi Pacific’s bow thrusters was not operational at the time of the accident, the ‘management of change’ (MoC) process implemented as a result of its failure was appropriate. The vessel was capable of conducting operations within the limitations/conditions defined by the MoC process, and did so while on station at and off the rig.

Safety analysis

The accident

At 0505 on 14 July, Skandi Pacific’s chief mate stopped backloading after the vessel’s DP system was no longer able to maintain its positon within defined parameters in the deteriorating weather conditions. In the rough seas, waves were regularly coming on deck over the vessel’s open stern.

By 0507, the chief mate had stepped Skandi Pacific out, to about 30 m off the rig on its leeward side, in DP mode. He then instructed the IRs to lash the containers on the aft deck.

At about 0520, after the IRs had lashed the cargo they found two mini-containers on the starboard side forward, not properly secured by the primary chain. In order to better secure the containers, the IRs decided to use a secondary chain secured to the crash barrier and then to the primary chain. Tightening the secondary chain would tighten the primary chain against the mini-containers. Their plan required tensioning down the tugger wire (and hence the primary chain). When they slackened the chain, the block of cargo on the starboard side was unsecured.

At 0523, two large waves came over the vessel’s stern in quick succession, shifting the unsecured containers on the starboard side. Their movement caused the primary chain to tension (Figure 9). As a result, the slack chain was lifted up, blocking the escape route of the IR who had stepped inside the primary chain to secure the secondary chain to the crash barrier. Although he tried to move clear of the advancing containers, in the few moments he had (to get clear) his escape (route) was impeded by the chain and he could not get clear.

Figure 9: Diagrams to illustrate the event sequence leading to the accident

Source: Cargo manifest (annotated by ATSB)

Prevailing weather conditions

At 1500 on 13 July, a BoM weather forecast (Figure 10) was issued for the general area where the Atwood Osprey platform is located:

A high is stalling over the southwest coast of WA. The ridging associated with the high will keep a relatively tight E/SE’ly pressure gradient over the Pilbara and adjacent waters. Expect fresh to strong winds through the forecast period.

Monday 13 July Confidence High, Partly Cloudy

• Mean winds 25/30 knots (possibly up to 32 knots)
• Total wave 3.1 m to 3.5 m (possibly up to 4.0 m)

Tuesday 14 July Confidence High, Partly Cloudy, Mostly sunny

• Mean winds 23/28 knots (possibly up to 32 knots)
• Total wave 2.6 m to 2.9 m (possibly up to 3.5 m)

The forecast showed a temporary lull in the wind speed and sea/swell conditions during the early hours of the following day, 14 July.

Figure 10: BOM’s commercial weather services forecast for 13/14 July 2015

Source: Skandi Pacific

Later in the afternoon on 13 July, another OSV started cargo handling operations on the lee side of Atwood Osprey. Shortly after 1800, the rig’s controller instructed Skandi Pacific’s master that his vessel would be called in next, about midnight, after the other vessel had departed.

The master continued monitoring the weather conditions throughout his 1800-2400 watch. The DP capability plot (Figure 7) also indicated that the vessel could maintain position in the conditions. Therefore, he noted in his night orders to the watchkeeping officers:

Make sure you are happy with position keeping and vessel movement before starting any ops.

There is quite some backload.

Stow as well as possible i.e. good blocks to secure for transit back to port. Weather is due to deteriorate again so keep this in mind.

Call me if in doubt.

Standing orders apply.

Skandi Pacific’s CSM provided guidance based on G-OMO, which is considered to be the best practice for offloading and backloading cargo alongside offshore installations, including:

Weather Conditions

• Weather conditions must be appropriate for the operation
• Always stop work in adverse weather conditions
• Comply with relevant guidelines on weather criteria.

However, consideration of the weather conditions and what could be deemed ‘adverse weather’ is subjective. Further, the company’s safety management system (SMS) did not provide any clearly defined guidance on weather limits for undertaking deck cargo handling operations or triggers to stop operations. The only such guidance was contained in Skandi Pacific’s charterer’s marine operating guidelines for bulk cargo operations:^[40]

Weather Limit Guidelines

Provided proper preparations have been made, the appropriate bulk transfer checklist has been completed and all other factors considered and found favourable, the following weather limits are recommended for conducting bulk transfers between vessels and an offshore facility:

• Wind < 30 knots / 15 m/s
• Sea < 3 metres (significant wave height)^[41]

The master used these guidelines to determine that the cargo handling operations could proceed. At midnight on 13 July, the forecast weather conditions (wind speed and significant wave height) were within the above weather limits.

The company’s SMS did not contain any clearly defined limits or parameters for cargo handling operations in adverse weather conditions. To determine if the conditions were appropriate for operations was at the discretion of the master. On 14 July, one of the conditions that he stipulated was to stop work if there was water on deck.

Clearly defined limits in the SMS would have removed subjectivity from the decision making and established a common understanding for everyone involved in cargo handling operations.

Cargo handling operations on 14 July

Toolbox Talk

On July 14, Skandi Pacific’s master outlined the main points of the toolbox talk (TBT) for cargo operations to the persons involved in the cargo handling operations, that is, the IRs and 0000-0600 mates. The briefing outlined a number of pre-determined safety topics, including:

Type of operation, work equipment, methods/procedures to be adopted, communication, and human factor assessment, ‘Stop the Job’ policy, crane/lifting requirements, individual responsibilities for controls, access, manual handling, working environmental conditions, potential hazardous..., …‘good blocks stows’ and ‘lash cargo well.’

The weather conditions were also discussed and the master instructed the IRs and OOWs that if water was shipped on deck, then the work was to be stopped. All of them verbally acknowledged this instruction and then signed the TBT form. Further, before starting his duties, the IR on the 0200-0800 watch received a briefing from the chief mate and signed the TBT form to acknowledge he had been shown all the required provisions of the earlier TBT.

Water on deck

Between 0140 and 0502, seas were occasionally shipped on deck, increasing in regularity and size before 0500. Between 0502 and 0503, two large waves were shipped over the aft deck in quick succession, followed by another one at 0505 (Figure 11).

Figure 11: Seas washing across the aft deck at 0502 and 0505

Source: Skandi Pacific’s CCTV (annotations by ATSB)

Between 0507 and the time of the accident, after Skandi Pacific had stepped out from the rig, waves continued to be shipped on the aft deck from time to time. However, the IRs continued working, moving around the deck. At 0519, while they were at the aft end of the deck on the starboard side, a wave washed over the port side (Figure 12).

Figure 12: The CCTV frame at 0519

Source: Skandi Pacific’s CCTV (annotations by ATSB)

The design of the AHTS vessel with long, low aft decks without protective stern bulwarks meant that spray on deck and seas breaking over the stern were common. However, neither the mates nor the IRs on deck considered the water shipped on deck from 0502 onwards prevented the crew from lashing the cargo in those circumstances and conditions.

After the accident, the 0200-0800 IR who was also on deck stated that ‘at no time did he feel that we were working in unsafe weather conditions during any of the operations’. Hence, he did not consider stopping the job. This indicates that the definition of conditions when work was to be stopped, such as excessive water on deck, was subject to a person’s judgment and decision. The IRs statement suggests that there was a sense of security despite the worsening conditions.

Had the SMS contained clearly defined limits for excessive water on deck that necessitated stopping operations, the crewmembers would have been in a better position to make safe decisions. For example, the chief mate did stop backloading shortly after the DP status limit was exceeded. He had informed the rig that it was too rough with more water coming on deck making it dangerous for those operations and his crew. While the chief mate probably felt the need to ensure the cargo on deck was lashed, the risks to the men working on deck did not decrease by moving the vessel 30 m away from the rig. If anything, those risks increased as they moved around the deck lashing cargo in deteriorating weather conditions.

In submission to the draft investigation report, DOF management stated:

… There was no forewarning of the 2 unexpected waves, which occurred in close succession, and caused the incident.

However, between 0450 and the time of the accident, progressively larger waves were shipped on the vessel’s deck. The CCTV footage shows that during this period of about 33 minutes, at least 15 waves large enough to wash across the deck were shipped. When the vessel’s stern pitched into the wave coming over the stern, more water came on deck.

Backloading

From the commencement of cargo handling operations, six items were transferred to Atwood Osprey and nine items backloaded to Skandi Pacific. Figure 13 details the positions, relative sizes and types of cargo on deck after the cargo handling operations were suspended.

The shipboard CSM included guidance for crewmembers when backloading cargo:

• be aware that as soon as sea fastenings are released, there is a chance for the cargo to shift
• be aware of the potential of trapped hands between the tugger wire and cargo
• be aware that cargo can move when tightened by the tugger.

Securing mini-containers

It follows that if unsecured cargo can shift then safe practice is to minimise the amount of time the cargo is unsecured. The fact that cargo will be unsecured at times and be subject to external forces possibly leading to its movement should be identified through an appropriate RA.

In submission to the draft investigation report, DOF management stated:

Cargo is always unsecured for a period when backloading occurs. The Risk Assessment specifically dealt with the hazards posed by shifting cargo and stipulated additional control measures. The Toolbox Talk specifically provided for the cargo to be well lashed before departure.

However, the RA for loading deck cargo was completed before the cargo handling operations started. The identified hazard of shifting containers was to be mitigated by ‘Staying away from containers. Avoid enclosed areas’. After cargo handling operations were stopped at 0505, the RA was not reviewed nor were the risks associated with securing cargo in the prevailing conditions adequately assessed.

By about 0518, the IRs had hauled in the starboard tugger wire and tensioned the primary chain around the cargo. When checking the lashing, however, they found that forward two mini-containers were not secured and decided to use a secondary chain to secure them.

Figure 13: Stowage arrangement after cargo operations were stopped on 13 July

Source: Skandi Pacific’s master (annotated by ATSB)

Their plan involved tensioning down the primary chain and securing a secondary chain to it. They decided to shackle the end of the secondary chain to the primary, to allow it to run along without snagging (Figure 14).

Figure 14: Utilising a secondary chain to secure cargo deck

Source: DOF management (annotations by ATSB)

Shortly afterwards, one of the IRs left the aft deck to get the shackle. Meanwhile, at the container, the other IR remained in the crush zone on the starboard forward end of the deck. He was in between the primary chain and the forward mini-container, inboard and outside of the crash barrier (Figure 9).

While the intent of the plan was to secure the cargo properly, the risks associated with the sequence of intended actions were not properly assessed. Importantly, the risk of working near unrestrained cargo that would be more susceptible to shifting as the weather conditions deteriorated, was not assessed. Furthermore, they did not comply with the master’s instruction to stop work if water was shipped on deck.

In submission to the draft investigation report, DOF management stated:

No prior assessment of the risk or any policy or safety procedure would have prevented the incident.

However, the need to secure cargo was a foreseeable risk. Securing the cargo needed to be undertaken after making conditions safe for the men to work on deck. At about 0520, the risk increased when the tugger wire was tensioned down, leaving containers 14, 10, 9 and 11 unrestrained. The risk further increased when the IR stepped into the crush zone forward of the cargo stow. At 0523, when the two large waves were shipped, the entire stow moved forward.

Essentially, the dangerous conditions while the IRs were securing the cargo were compounded when the primary chain was tensioned down and the IR stepped into a position from where he did not have a clear and unobstructed escape route.

Suspending cargo handling operations

Skandi Pacific was alongside the rig for about 4 hours on 14 July. The vessel’s station keeping status deteriorated to yellow several times, as it shifted more than 2 m from the set position.

At 0503, an alarm activated indicating the DP system status was red (that is, the vessel was more than 4 m from its set position). The chief mate stopped operations as required by the procedures and informed the rig. However, no one called the master to inform him of the suspended cargo handling operations nor discuss the current situation and changed activities on deck.

The chief mate moved Skandi Pacific, in DP mode, about 30 m away from the rig, stayed in the lee of Atwood Osprey, and maintained a heading of between 237° and 238°. The sea conditions continued to deteriorate and waves continued to be shipped over the vessel’s open stern.

The chief mate then instructed the IRs to secure the cargo with the vessel in this position. However, the risks of securing cargo with rough seas on the quarter and the vessel pitching heavily at times and shipping seas on deck were not adequately assessed or reviewed. Further, the master’s instruction to stop work if water was shipped on deck was not complied with.

Amongst the options the chief mate indicated he had considered were running with the weather until the cargo was secured or stepping out from the rig and staying in the lee until the cargo was secured. He had taken the latter option as in his opinion staying in the sheltered position off the rig was the safest option.

However, with rough seas on the quarter, the vessel pitching heavily at times and shipping seas on deck, it would have been prudent (and necessary) for the chief mate to call the master and discuss cargo securing options with him and the IRs. In other words, a review of the previous risk assessment or a reassessment. Calling the master would also have provided him the opportunity to reiterate or clarify his instruction that work be stopped if there was water on deck.

Had the chief mate called the master, other options to secure the cargo could have been considered. For example, in this situation the master indicated that he would have also considered running with the weather or tensioning the tugger wire around the cargo, then turning the vessel to protect the crewmembers on deck. As a result, the opportunity for the master to consider available options to prevent or reduce the likelihood of waves being shipped over the stern was lost.

Supervision and communication

Skandi Pacific’s risk assessment for cargo transfer stated ‘Minimum of two competent persons to be on the bridge, one solely in charge of the DP, one monitoring communications and watching around the vessel for dangers. However, at about 0520 on 14 July, the chief mate, who was solely in charge of the DP system, was performing both tasks. At that time, the second mate on duty was in the forward part of the bridge entering the passage plan to Dampier into the electronic chart display and information system.

Communications between the bridge and the IRs on deck was maintained via UHF and VHF radio. At the time of the accident, the IR securing the secondary chain had the VHF radio for communications with the bridge and the rig’s crane. The IR who went to get the shackle had the UHF for direct communications with the bridge.

The risk assessment also required two men to be on deck when carrying out cargo operations. At interview, the master stated this was partly to ensure that no individual went into a crush zone without another watching for water coming over the stern and also to watch out for the other. However, this situation occurred shortly before 0523 when the IRs were separated as one IR went to the deck locker (located about 10 m forward) to get the shackle. It was during this short period of time (30 seconds) that seas broke over the stern and shifted the containers.

While the chief mate warned the deck crewmembers over the UHF radio ‘watch out, water on deck’, the IR working on the secondary chain did not have a UHF radio. In any case, even if he had heard the warning, he would have had little time to react.

Skandi Pacific’s procedures for cargo handling alongside installations included the following for backloading operations:

The OOW in charge of backloading should always have full sight of all cargo operations and personnel on deck including the crane wire and hook.

Figure 15: Line of sight of Skandi Pacific’s aft deck from the Bridge

Source: DOF Management (annotated by ATSB)

After the IRs had initially tensioned the tugger wire at about 0518, the chief mate observing from the DP console (Figure 15) on the bridge, believed that the cargo handling operations had been completed. After the accident, the chief mate stated ‘I thought they were almost finished as they were both out of sight and I could see the chains tightening’.

The aft deck had CCTV coverage and was visible on the monitors above the DP console. In this way it was possible to monitor the status of the work as far forward as the tugger winch including the area in which the IRs were working. However, the chief mate was the DPO and his responsibilities operating the DP system did not allow him to continuously monitor the CCTV screen. Furthermore, he was not aware of the IRs plans and intentions to secure the mini-containers as they did not inform the mates on the bridge.

In submission to the draft report, DOF management stated:

The IRs are not required to report that information to the mates. That was work which was performed by the IRs in the ordinary course of operations.

However, lashing cargo in the prevailing conditions with rough seas on the quarter with the vessel pitching heavily at times and shipping water on deck, was not the ‘ordinary course of operations’. Working in those high risk conditions was also contrary to the master’s instructions. The risks further increased when the IRs tensioned down the primary chain at about 0520 and then started rigging the secondary chain. At 0522, both men were working forward of the mini-container. Had one of them not left to get a shackle, the consequences of the accident could have been worse.

In any case, the purpose of the IRs carrying the two radios clearly was two-way communication to mitigate any risks by having a common understanding of the work/situation and for important messages, including warnings to be issued.

Exposed aft deck

Skandi Pacific’s aft deck had an open stern, which permitted seas to be shipped. The shipboard operating procedures for cargo handling alongside installations identified the exposed deck as follows:

Open stern anchor handling vessels require special care and consideration should be given to the open stern being physically barriered.

The procedures also stated the crewmembers and cargo were exposed to the elements when working with the stern towards the weather. The guidance stated that a RA and TBT were to be used to minimise their exposure to the weather.

However, Skandi Pacific’s managers had not adequately assessed the risks associated with working on the aft deck of vessels with open sterns, including the consideration of engineering controls to minimise shipping water on the vessel’s aft deck.

DP status

On 8 July, Skandi Pacific’s master submitted a management of change (MOC) form for a change of situation because number two bow thruster was out of service. This meant that the vessel no longer met DP class 2 status requirements.

The MOC form noted:

• Conditions of working alongside installation to be assessed by master and rig’s OIM prior to entry of 500 m zone and deemed acceptable.
• Manual manoeuvring if weather is acceptable but there is a force pushing on, however, resultant force must be drift off. No hose work in this instant.
• DP class 1^[42] criteria for leeside working.
• RA to be done if hose work is intended stern should be into weather to reduce effect of loss of bow thruster.

The change in operational conditions necessitated a new or revised RA to be completed before work could be started.

The MOC was signed by the master, vessel manager and marine advisor. An additional RA was then undertaken, for working on an installation with DP class 1 status, when on the lee side of the rig. The activities assessed were setting up DP, DP work on lee side and deck cargo handling operations.

The risk level was assessed as ‘medium’^[43] which required additional control measures be implemented to reduce the residual risk level to ‘low’.^[44]

The measures put in place following the failure of the bow thruster were appropriate in the prevailing circumstances. Skandi Pacific was manoeuvred into position off the oil rig, stern in, on a heading of between 237° and 238°, similar to the previous OSV. The vessel maintained position on station at the rig until 0505, when operations were stopped by the chief mate.

__________

40. Bulk cargo operations involves the transfer of potentially hazardous liquids by use of hoses between vessel and rig.
41. The average of the highest one-third of a set of measured waves. The maximum wave height can be up to twice the significant wave height.
42. DP equipment class 1 has no redundancy. Loss of position may occur in the event of a single fault.
43. Task should only proceed with appropriate management authorisation after consultation with special personnel and assessment team. Where possible the task should be redefined to take account of the hazards involved or the risk should be recorded further prior to task commencement.
44. The task may be acceptable, however, it should be reviewed to determine if the risk can be reduced further.

The occurrence

At 1515^[1] on 7 July, Skandi Pacific (Figure 1) sailed from the Port of Dampier with a cargo for the semi-submersible oil rig, Atwood Osprey (Figure 2), about 90 miles^[2] north-west of Dampier.

Figure 1: Skandi Pacific and Figure 2: Atwood Osprey

Source: DOF Management Source: Atwood Oceanics

At about 0600 on 8 July, Skandi Pacific arrived on location at the rig. The vessel was scheduled to carry out cargo handling operations over the following days. Throughout that time, the vessel’s master and mates maintained a two person, 6-on/6-off schedule for navigational watches.

Over the next few days, Skandi Pacific cargo handling operations were conducted with the vessel in Dynamic Positioning^[3] (DP) mode.

The wind throughout this time was from the south-southeast at force^[4] 5 to 6 (17 to 27 knots).^[5]

On July 10, the weather deteriorated and winds increased to force 8 to 9 (34 to 47 knots) preventing Skandi Pacific from carrying out cargo handling operations. The adverse weather conditions continued over the following days and the vessel remained on standby off the rig.

On 13 July, Skandi Pacific’s master received Bureau of Meteorology (BoM) reports, including its commercial weather services report, forecasting that conditions would ease temporarily during the early morning of 14 July.

During the 1800-2400 watch on 13 July, Skandi Pacific was standing off the rig. The master noted in his night orders that cargo handling operations were due to commence after another offshore support vessel (OSV) had departed. In his orders, he also stated that ‘the weather was due to deteriorate again so keep this in mind’.

At 0010 on 14 July, the rig’s controller called Skandi Pacific’s master and instructed him to move into the 500 m exclusion zone off the rig and prepare to backload cargo (cargo transfer from the rig to the vessel). Shortly after, the master handed over the watch to the chief mate. The master then remained on the navigation bridge (bridge) and conducted a toolbox talk^[6] for the cargo work with the chief mate, second mate, and the two integrated ratings^[7] (IR) who were to be on deck during cargo work.^[8] This talk included instruction for crush hazard awareness, backloading cargo in block stows, escape routes and for the IRs to stop work if seas were shipped on deck.

Shortly thereafter, the master left the bridge. At that time, the wind was easterly at 15 to 25 knots with 2 to 3 m seas, consistent with the weather forecast.

Figure 3: Dampier and position of the Atwood Osprey

Source: Australian Hydrographic Service with ATSB annotations

At about 0025, Skandi Pacific’s chief mate moved the vessel closer to the rig, as planned, and placed it in DP mode. At 0045, after completing the DP checklist, he began moving it under the rig’s loading platform, which was on its leeward side. At about this time, the master briefly returned to the bridge. He noted the weather as acceptable for the operations, with occasional sea spray on deck.

By 0105, the chief mate completed the move and the two IRs were already on deck, releasing lashings in preparation for backloading empty mini-containers, open top containers and 10-foot sea containers from the rig.

At 0140, backloading of containers from the rig started and from time to time, there was spray across Skandi Pacific’s deck. The vessel’s motion in the seas meant that it moved around its position under the loading platform, but the DP system kept it within the set range (2 m) and on a true heading^[9] of between 237° and 238°.

Shortly before 0200, the IR starting his watch came to the bridge for the toolbox talk and signed the briefing form. He then proceeded to the aft deck and the IR completing the 2000-0200 watch handed over to him and left the deck.

At 0400, the wind was recorded in the vessel’s deck log book as northeast force 5 to 6 (17 to 27 knots). The sea state was recorded as 5 (that is, wave height 2.5 to 4 m or rough seas). In those weather conditions, waves were occasionally shipped on deck over the vessel’s open stern. This became more frequent over the next hour and, in the minutes before 0500, some bigger waves washed across a large part of the aft deck.

At 0501, the second of two mini-containers was landed at the forward part of the aft deck on the starboard side. The IRs released the crane hook from the container and moved clear. Between 0502 and 0503, two waves were shipped on deck in succession as the vessel pitched with the water washing forward about 40 m across the port side of the aft deck.

At 0503, the DP status alarm triggered indicating that Skandi Pacific had moved outside the set limit of 4 m. The chief mate informed the rig that it was ‘too rough’ with the vessel getting pushed ‘further out of position’ and ‘more and more water’ coming on deck, making it ‘dangerous’ for the operations and the men on deck. He asked the rig to stop backloading and then advised the IRs that the operations had been suspended. The deck log book entry stated ‘0505 Stop Job, weather increasing in strength’. Shortly after 0505, another large wave came over the stern.

By 0507, the chief mate had stepped Skandi Pacific about 30 m to leeward of the rig. The vessel remained in DP mode and on the same heading. He then instructed the IRs to lash the containers on deck.

Shortly thereafter, the two IRs moved aft to start lashing the containers. From the chief mate’s seated position at the DP console, facing aft, he could see the men as they moved around the aft end of the deck. They first lashed the cargo platforms on the port side with chains, run from the crash barrier at the stern of the vessel around the platforms. The chains were attached at the forward end of the deck to a tugger wire^[10] and tensioned with the port tugger winch.

By 0511, the IRs had completed lashing on the port side. During this time, a couple of smaller waves had been shipped on deck.

At 0512, the IRs moved to the starboard side cargo stow, which included open top, mini and 10-foot sea containers. They moved between the vessel’s stern and the forward part of the stow. A few smaller waves came over the stern during this time.

By about 0518, the IRs had lashed the cargo stow using the starboard winch to heave the tugger wire (in a similar manner to the port side) to tension the chains rigged around the containers. They then began checking the lashings starting from aft. At 0519, while they were aft at the starboard quarter, a wave came over the port quarter and washed across the port side.

At about 0520, when the IRs checked the forward part of the stow, they found the two forward mini-containers were not properly secured by the primary chain. They decided to secure them using a secondary chain secured to the crash barrier between the mini-containers and the skip, and then to the primary chain (Figure 4). When tightened, the secondary chain would tighten the primary chain against the mini-containers. That would require the primary chain to be slackened off (tensioned down – the term used on board the vessel).

Shortly thereafter, the tugger wire was payed out, which again unsecured the entire starboard cargo stow. No one informed the mates on the bridge that the primary chain had been tensioned down.

The IRs began rigging the secondary chain forward of the mini-containers. They decided to use a shackle looped around the primary chain and secured to the end of the secondary chain. This arrangement would allow the shackle to run along the primary chain and keep the tension in it.

At 0522, both IRs were preparing the secondary chain. Thirty seconds later, one IR went forward to the nearby store to get the shackle, leaving the other to connect the chain to the crash barrier.

Figure 4: Skandi Pacific’s aft deck securing chain arrangement

Source: Skandi Pacific’s CCTV at 0521 on 14 July 2015 (annotated by ATSB)

Moments before 0523, a large wave came over the stern and washed across the deck. The water on deck had not yet receded, when a larger wave came over the stern. From his position on the bridge, the chief mate had seen the seas coming over the stern and called out a warning to the men on deck over the UHF radio. The IR getting the shackle had the UHF radio while the one rigging the secondary chain had the VHF radio.

At 0523,^[11] as the large quantity of water washed forward along the deck, it shifted some of the starboard side cargo containers (Figure 5) and continued as far forward as the Skandi Pacific’s superstructure. The IR rigging the secondary chain just forward of the mini-containers tried to move clear of the advancing containers but did not have enough time to get clear. He was trapped in between the forward mini-container and the primary chain, and was crushed against a skip.

Figure 5: Aft deck plan showing stowage and other key positions

Source: DOF Management (annotated by ATSB)

The IR returning with the shackle heard the warning over his radio. When he reached the mini-containers, he saw the injured man. He immediately called the bridge and informed the chief mate that the other IR had been injured. The chief mate told the second mate on watch with him to call the master, and to take over the DP console. He then went to the accident area.

Shortly thereafter, the master arrived on the bridge, and the second mate informed him that an IR was pinned between the deck cargo. The master called the rig, advised that there had been an accident and requested medical assistance.

At 0527, the master sounded the general alarm followed by a public address to muster all crewmembers at their stations. He also asked the rig to arrange a helicopter for a medical evacuation

A short while later, the chief mate and other crewmembers freed the IR, who was unresponsive. The crewmembers then started cardiopulmonary resuscitation (CPR) on the seriously injured man and the master manoeuvred Skandi Pacific under the rig’s loading platform.

At 0605, three crew from Atwood Osprey, including two medics boarded Skandi Pacific. They continued CPR and moved the injured IR onto a stretcher in preparation for transfer to the rig.

At 0613, the injured IR was transferred to Atwood Osprey. He was then taken to the rig’s hospital, where, at 0630, the medics declared him deceased.

__________

1. All times referred to in this report are local time, Coordinated Universal Time (UTC) + 8 hours.
2. A nautical mile of 1852 m.
3. Dynamic Positioning is a computer-controlled system to automatically maintain a vessel's position and heading by adjusting its propulsion units to suit the weather and sea conditions.
4. The Beaufort scale of wind force, developed in 1805 by Admiral Sir Francis Beaufort, enables sailors to estimate wind speeds through visual observations of sea states.
5. One knot, or one nautical mile per hour equals 1.852 kilometres per hour.
6. The toolbox talk communicates the risk assessment and specific controls to the work party.
7. Integrated ratings are qualified to perform the duties of both an able seaman and an engine rating.
8. The IRs’ working hours consisted of sea watches, plus 2 hours either before or after their watch during cargo operations. On 13/14 July, the three IRs work routines were 2000-0200, 0000-0600 and 0200-0800. Additionally, a day work IR was available from 0600-1800.
9. All ship’s headings in this report are in degrees by gyro compass with negligible error.
10. Relatively small (15-20 mm) diameter wires, stowed on their own winches, one each side at the forward end of the working deck. The direction of pull is facilitated by passing the wires through snatch blocks, which can be secured in various places along the working deck.
11. The accident was recorded in the vessel’s deck log book at 0525, some 2 minutes later than the CCTV footage.

Sources and submissions

Sources of information

The sources of information during the investigation included:

• Skandi Pacific’s master and directly involved crewmembers
• DOF Management
• Geoscience Australia
• National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA)
• Australian Maritime Safety Authority (AMSA).

References

International Maritime Organisation, 2015, The International Convention for the Safety of Life at Sea (SOLAS) 1974, as amended, IMO, London.

International Maritime Organisation Resolution A.489(XII), Adopted on 19 November 1981, Safe Stowage And Securing Of Cargo Units And Other Entities In Ships Other Than Cellular Container Ships Cargo Securing Manual.

International Maritime Organisation Resolution A.863(20), Code of Safe Practice for the Carriage of Cargoes and Persons by Offshore Support Vessels (OSV Code), as Amended.

Guidelines for Offshore Marine Operations (G-OMO), Guidelines for Offshore Marine Operations Revision: 0611-1401, 2013. Visit www.g-omo.info and follow the link on the G-OMO tab to Guidelines for Offshore Marine Operations.

National Offshore Petroleum Titles Administrator (NOPTA), Offshore Petroleum and Greenhouse Gas Storage Act 2006. Visit www.nopta.gov.au and follow the link on the Legislation, determinations, guidelines & fact sheets tab to offshore petroleum acts.

Ritchie, G 2008, Offshore Support Vessels, A Practical Guide, The Nautical Institute, UK. Visit www.nautinst.org and follow the link on the Publications to the publications list.

Submissions

Under Part 4, Division 2 (Investigation Reports), Section 26 of the Transport Safety Investigation Act 2003 (the Act), the Australian Transport Safety Bureau (ATSB) may provide a draft report, on a confidential basis, to any person whom the ATSB considers appropriate. Section 26 (1) (a) of the Act allows a person receiving a draft report to make submissions to the ATSB about the draft report.

A draft of this report was provided to the Australian Maritime Safety Authority, The Bahamas Maritime Authority, DOF Management, National Offshore Petroleum Safety and Environmental Management Authority and the master, chief mate, second mates and integrated ratings on board Skandi Pacific and the integrated rating’s next of kin.

Submissions were received from the Australian Maritime Safety Authority, The Bahamas Maritime Authority, DOF Management, National Offshore Petroleum Safety and Environmental Management Authority and the master on board Skandi Pacific and the integrated rating’s next of kin. The submissions were reviewed and where considered appropriate, the text of the report was amended accordingly.

Purpose of safety investigations & publishing information

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through: identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

The occurrence

A limited-scope, fact-gathering investigation into this occurrence was conducted in order to produce this short summary report and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

In the early hours of 10 July 2015, Hyundai Dangjin (cover) was in the final stages of loading its cargo of iron ore at Port Walcott, Western Australia. The ship was starboard side alongside the wharf and the chief mate and draught surveyor were on the wharf to check the ship’s draught. They could see the forward and aft draught marks but not the midships marks.

At 0450,^[1] the chief mate asked the second mate, via UHF radio, to read the midships draught on the ship’s port (outboard) side. The ship’s crew had already rigged a rope ladder (Figure 1) adjacent to the draught marks there.

Figure 1: Rope ladder, as rigged at the time of the accident

Source: Australian Maritime Safety Authority

In preparation to climb down the rope ladder, the second mate donned a life vest (non-inflatable flotation aid). The able seaman (AB) on duty offered to go down the ladder instead of the second mate, who was a large and heavy man. The second mate declined the AB’s offer (mates are trained to read draught marks).

Just after 0455, the chief mate and draught surveyor returned from the wharf to the ship’s office. The chief mate then called the second mate and asked for the midships draught. The second mate did not reply.

At that time, the second mate was near the bottom of the ladder, about 7 m below the ship’s deck. He called out to the AB for help and said he was having difficulty. When the AB checked, he saw the second mate struggling to hold on to the ladder. As the AB looked around for a rope to throw down, the second mate fell into the water. The AB threw a nearby lifebuoy to the second mate and it landed a few metres away.

The second mate tried to swim to the lifebuoy, but was not able to reach it. The sea was rough (1.4 m sea on a 0.4 m swell) and the water temperature was about 22 °C.

Rescue attempts

At about 0458, the AB called the third mate on the radio and told him that the second mate had fallen into the water. The AB then climbed down the ladder and entered the water. At this time, the second mate was about 4 m from the ladder and drifting further away. The AB had difficulty breathing and swimming in the rough, cold seawater. He was unable to reach the second mate and returned to the ladder.

The third mate reported the man overboard to the chief mate, before hurrying to the rope ladder. When he arrived there, he saw the second mate about 20 m from the ladder. His arms were moving slowly and he was not getting any closer to the lifebuoy about 3 m away. The third mate then went aft to get a lifebuoy with a lifeline attached.

At about 0510, the chief mate informed the master that the second mate had fallen from the rope ladder. The master left his cabin and went to the ship’s office, where he ordered that the port accommodation ladder and pilot ladder be lowered to the water.

The AB was at the bottom of the rope ladder when an ordinary seaman (OS) arrived. The AB was already suffering from the effects of the cold water and was having trouble holding on to the ladder. The OS threw a rope to the AB and he tied it around his waist.

Meanwhile, the third mate returned with a lifebuoy with a lifeline and threw it towards the second mate. The lifebuoy landed close to him and he was able to get an arm through it. The third mate then started to pull him towards the ship’s side near the rope ladder.

The AB had remained at the bottom of the ladder, to assist the second mate when he was close enough. When the second mate was about 5 m from the ship’s side, crew at the scene saw that he was no longer holding onto the lifebuoy.

Raising the alarm

At about this time, the chief mate arrived on deck near the rope ladder. He saw the AB holding on to the bottom of the ladder, up to his waist in the water. The chief mate took the lifebuoy line from the third mate and instructed him to go to the bridge and raise the alarm.

At about 0512, the third mate rang the general alarm. He then announced over the ship’s public address system that there was a man in the water, and for the crew to go to their muster stations.

The AB could not assist the second mate who was drifting further away, so he climbed the ladder to the deck. He was suffering from the effects of the cold water and exhaustion and was escorted to the ship’s hospital by two other crewmembers.

As the second mate drifted further aft, the chief mate continued to call out to him and shine a torch in his face. He did not receive any response.

When the third mate returned to the main deck, the accommodation ladder had been lowered to the water level. He climbed down and was able to drag the second mate onto the ladder’s lower platform. He then commenced cardiopulmonary resuscitation (CPR) on the second mate while the accommodation ladder was being raised to deck level with both men on its lower platform.

By 0520, two members of the terminal’s emergency response team and the port’s emergency management officer had boarded Hyundai Dangjin. Shortly after, when the accommodation ladder was at deck level, they visually assessed the second mate and detected no signs of life.

The master was concerned due to the gap between the ship’s side and the accommodation ladder platform, and the second mate’s weight. In order to avoid a further incident, he instructed his crew to transfer the second mate to the deck using the stores crane and a suitable sling. The master then went to inform the ship’s managers of the accident.

At 0540, the AB, suffering from hypothermia symptoms, was taken ashore for assessment at a local hospital.

At about 0555, a St John Ambulance paramedic boarded the ship. By this time, the second mate had been moved to the deck, CPR was continued and the paramedic assessed him. At 0605, after finding no sign of life, the paramedic informed the master that the second mate had died.

ATSB comment

The rope ladder had been rigged upside down (Figure 1). With their wrong side up, the ladder steps (folded aluminium) did not provide a flat surface to stand on comfortably. Further, the steps were not good handholds.

The sole precaution taken by the second mate while reading the draught marks was his life vest. No fall prevention measures were put in place or used. The life vest’s specifications could not be determined but similar types provide around 7 to 10 kg of buoyancy.

While the AB was standing by on deck, man overboard response measures (such as a lifebuoy with light and line near the ladder) were not in place. Fortunately, his well-intentioned but impulsive descent of the ladder in an attempt to rescue the second mate did not result in another casualty.

The second mate’s initial postmortem examination report stated the cause of death as ‘undetermined (pending further investigation)’. However, the report noted that some findings of the examination ‘could be seen with drowning’. The report stated that the body was of a man of large build and included his height and weight. This is consistent with the attending police officer’s report, which noted that the second mate ‘was a man of large overweight build’.

Safety action

Whether or not the ATSB identifies safety issues in the course of an investigation, relevant organisations may proactively initiate safety action in order to reduce their safety risk. The ATSB has been advised of the following proactive safety action in response to this occurrence.

Toyo Sangyo

Toyo Sangyo Company (Toyo Sangyo), Hyundai Dangjin’s managers, have taken the following safety actions to avoid a similar accident.

Review of shipboard safety management system

Toyo Sangyo’s review of its shipboard safety management system (SMS) resulted in a ‘Safe Draft Check Instruction’ being included in the procedures related to cargo operations for bulk carriers. The instruction details the procedures (including permits to work) when checking the ship’s draught from a rope ladder.

The ship’s managers issued a circular to its managed fleet to raise awareness of the accident, lessons learned and inform crew of the changes to SMS procedures.

Rio Tinto Iron Ore

Review of draught survey methods

Rio Tinto Iron Ore, the Port Walcott terminal managers, reviewed the draught survey methods at its terminals. As a result of the review, the reading draught marks from rope ladders was prohibited. An alternate method, using a manometer, was put in place.

Rio Tinto Iron Ore has promulgated the revised draught survey requirements and methods through a circular to all of its terminals. The revised requirements and methods have also been provided to ship’s agents for inclusion in pre-arrival information for shipmasters.

Safety message

In many cases, little attention is paid to planning apparently straightforward tasks, such as using a rope ladder. This can lead to important factors and relevant considerations not being taken into account, including the experience and physical ability of persons undertaking the task.

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through: identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

__________

1. All times referred to in this report are local time (WST), Coordinated Universal Time (UTC) + 8 hours.

What happened

At about 1618 Eastern Standard Time on 8 July 2015, the pilot/owner of an amateur-built Pitts Model 12, registered VH‑JDZ, took off from Maitland Airport, New South Wales.

Witnesses reported hearing a loud engine noise at about 1630 that caught their attention. They then observed the aircraft at the top of what appeared to be a vertical climb. The aircraft slid backwards, tail first, before entering a horizontal spin. Shortly after, the witnesses lost sight of the aircraft below the tree line and some reported hearing a loud bang.

The aircraft was located by search aircraft and ground personnel who arrived at the site of the accident at about 1715. The aircraft had collided with terrain in thick bushland, fatally injuring the pilot. The aircraft was destroyed by impact forces and an intense post-impact fire.

What the ATSB found

Radar data and witness reports were consistent with the aircraft being used for aerobatic manoeuvres in the minutes prior to the accident.

The ATSB considered the results of the pilot’s post-mortem examination, which indicated the pilot had coronary artery disease that may have resulted in permanent incapacitation. However, while that remained a possibility, there was insufficient evidence to conclude that it influenced the development of the accident. The ATSB found that for reasons that could not be determined, VH‑JDZ entered a vertical manoeuvre from which the pilot did not regain control before colliding with terrain. Additionally, the aircraft was being flown at a height which reduced the time available to effect a recovery, if required.

The ATSB also identified instances of misinterpretation of a number of the regulations concerning the maintenance of amateur-built experimental aircraft. This has the potential to affect the safety of these aircraft and those on board.

Safety message

Aerobatic flying requires extensive training and ongoing commitment to maintain the skills necessary for safe operations. Unauthorised aerobatic manoeuvres increase the risk to the pilot, any passengers and third parties in the vicinity of the aerobatics.

Flying at low level reduces the safety margin available should something unexpected happen. The ATSB has issued a series of ‘Avoidable Accidents’ publications, the first of which details the risks involved in low-level flying and includes the following statement:

Low-level flying also presents fewer opportunities to recover from a loss of control compared to flight at higher altitudes. It takes time to react and to regain control of an aircraft, and the closer to the ground you are, the less time and distance you have. Flying at low altitudes is not only risky when things are going right; it becomes downright perilous when things are going wrong.

More information is available from the ATSB’s avoidable accident web page.

Finally, ongoing safety requires aircraft owners and maintainers to operate and maintain the aircraft in accordance with relevant regulations, including those specific to experimental aircraft. Aircraft operation and maintenance outside the regulatory requirements increases safety risk.

Amateur-built Pitts Model 12 registered VH-JDZ

Source: Supplied

Safety analysis

Background

The private flight in a Pitts Model 12, registered VH-JDZ (JDZ), was conducted in favourable weather conditions but ended in a collision with terrain, fatally injuring the pilot. The witness observations were consistent with the aircraft exiting a vertical manoeuvre in an uncontrolled state, with insufficient height for recovery before impacting terrain. Wreckage and accident site examination indicated that the aircraft collided with terrain inverted, slightly nose-down and with little or no forward speed.

Given the extent of the impact damage and intensity and effect of the post-impact fire, there was no evidence that any mechanical failure or aircraft unserviceability contributed to the development of the accident. In addition, the surrounding area contained cleared and open paddocks, which could have been used for a precautionary or emergency landing had that been required.

This analysis will consider the circumstances that preceded the loss of control.

Unauthorised flight manoeuvres

The pilot was appropriately licenced to fly JDZ solo and had been encouraged to fly the aircraft solo and with an instructor to increase familiarity and gain experience on type. The pilot did not hold the required authorisation to conduct aerobatic manoeuvres or fly at low altitude. The pilot’s instructors advised the pilot to not conduct solo aerobatic manoeuvres. However, radar surveillance data and witness reports were consistent with the pilot conducting aerobatic manoeuvres in the minutes preceding the impact with terrain. This included flight below 200 ft above ground level.

The pilot’s decision to conduct the aerobatic manoeuvres solo, and without authorisation, increased the risk of unintended departure from controlled flight. In addition, the pilot’s conduct of those manoeuvres at low altitude reduced the height, and therefore the time available in which to recover control of the aircraft should it depart from controlled flight.

The observed vertical manoeuvre, followed by the reported horizontal flat spin is consistent with a loss of control. The reason for the loss of control could not be determined.

Flight control fouling

The forward seat harness buckles were found unsecured during the wreckage examination. The post-impact fire hindered the ATSB’s ability to determine if the harness had been secured in a non-standard manner prior to the flight, increasing the risk that they might unbuckle. In addition, although unlikely, the possibility that if buckled correctly the buckles may have come undone as a consequence of the impact sequence could not be discounted. Despite these possibilities, the ATSB concluded that the as-found insecurity of the front seat harness buckles suggested that they were not secured correctly as part of the standard pre-flight preparation for solo flight.

Unsecured harnesses have the potential to interfere with the flight controls, in particular during aerobatic flight. The cockpit layout would have inhibited the pilot’s ability to clear such an interference in flight. Any interference could result in an unintended manoeuvre or inhibit the pilot’s ability to recover from a manoeuvre, whether the manoeuvre was intended or unintended.

While flight control fouling remains a possibility, there was insufficient evidence to determine if it was a contributor to the accident.

Pilot incapacitation and non-reporting of medication

Pilot incapacitation can impair a pilot’s performance to the extent that safe operation of the aircraft is adversely affected. It can be due to the effects of a medical condition or a physiological impairment and represents a potential threat to flight safety. It can have either a long- or short‑term effect on the pilot.

The pilot’s post-mortem examination indicated that the pilot had coronary artery disease that could have resulted in a permanent incapacitation event. In addition, reports of other flights indicated the pilot suffered from temporary incapacitation as a result of nausea caused by the onset of g forces. Further, the use of non-prescribed medical or herbal supplements or the effects of a cold or virus can increase the risk of pilot incapacitation. The conduct of aerobatic manoeuvres can exacerbate the effects of a number of these conditions and non‑prescribed ‘treatments’.

All of these factors were present during this occurrence and pilot incapacitation could have preceded the loss of control or influenced any recovery. However, while an incapacitating event remained a possibility, there was insufficient evidence to conclude probable contribution to this accident.

Many documents highlight the risks involved with various medications and their possible effects on pilot performance and flight safety. The Designated Aviation Medical Examiner reported being unaware of all medications and supplements reported taken by the pilot. Therefore, the medical examiner was unable to determine any possible interactions between the prescribed anti‑hypertensives and/or the non‑prescribed medication and herbal supplements. This removed a potential protection against the risk of pilot incapacitation as a result of those medicines and supplements.

Maintenance

The ATSB found that uncertified maintenance was conducted on JDZ by authorised and unauthorised persons. The registered operator is responsible for the airworthiness and maintenance control of the aircraft to ensure its safe operation. Additionally, the pilot in command must not commence a flight unless all required maintenance has been completed and certified.

This and other ATSB investigations have reiterated the importance of adhering to the regulations as they apply to aircraft maintenance and operation. However, there is evidence that some in the industry are unsure of, or are misinterpreting a number of the regulations concerning the operation and maintenance of amateur-built experimental aircraft. Authorised aircraft maintenance is mandated to assure a level of safety for aircraft operations. Unauthorised maintenance increases the risk of mechanical failure, in turn reducing the level of safety and increasing the risk of injury or death.

Sources and submissions

Sources of information

The sources of information during the investigation included the:

• Civil Aviation Safety Authority
• New South Wales Police and Coroner
• Department of Defence
• Airservices Australia
• Bureau of Meteorology
• a number of flight instructors and Pitts Model 12 pilots
• aircraft kit manufacturer and builder
• maintainers of VH-JDZ.

Submissions

Under Part 4, Division 2 (Investigation Reports), Section 26 of the Transport Safety Investigation Act 2003 (the Act), the ATSB may provide a draft report, on a confidential basis, to any person whom the ATSB considers appropriate. Section 26 (1) (a) of the Act allows a person receiving a draft report to make submissions to the ATSB about the draft report.

A draft of this report was provided to the Civil Aviation Safety Authority, the United States National Transportation Safety Board, the aircraft kit manufacturer, a number of flight instructors, the Department of Defence and Airservices Australia.

No submissions were received from those parties.

Context

Pilot information

The pilot commenced flying in December 2006 and was issued with a Private Pilot (Aeroplane) Licence in January 2008. In addition, the pilot was endorsed for single-engine aeroplanes not exceeding 5,700 kg maximum take‑off weight and category design features including retractable undercarriage and manual propeller pitch control.

The pilot had accrued about 750 hours flying experience, mostly in Piper PA32 and Eagle Aircraft 150-type aircraft. The pilot completed an emergency manoeuvre training course in a Pitts S2A in June 2010 and commenced aerobatic training in a similar aircraft in August 2012. In February 2014, the pilot was issued an endorsement to fly ‘tail wheel undercarriage aircraft’ and completed a flight review at the same time.

The pilot commenced dual familiarisation flying in VH-JDZ (JDZ) in December 2014. Basic aerobatic training was also conducted in JDZ from March 2015. At the time of the accident the pilot had accrued about 22 hours in JDZ, of which about 7 hours was solo. The pilot’s aerobatic flying experience, under instruction and in a Pitts S2A, a Yakovlev Yak 52 and JDZ, totalled about 21.5 hours.

The pilot had not yet achieved the required competency to be authorised for spinning or an aerobatic endorsement. In addition, the pilot was advised by his instructors to not conduct solo aerobatics.

The pilot held a current Class 2 Medical Certificate that was issued on 22 January 2015.

Aircraft information

General

JDZ was an amateur-built Pitts Model 12 two-seat tandem biplane, serial number 42. It was powered by a Vedeneyev M14P radial engine and had a two-blade composite constant speed propeller. The only special requirements to operate the Pitts Model 12 were an endorsement for tail wheel undercarriage and for manual propeller pitch control.

The pilot purchased JDZ from the builder on 11 November 2014 and became the registered operator on 11 December 2014.

Construction and certification

JDZ was purchased as a kit from the aircraft manufacturer in the United States and assembly commenced in Australia in 1999. The aircraft was issued with a Special Certificate of Airworthiness (SCOA) on 24 October 2006. An annex to the SCOA outlined a number of Phase I operational limitations and specific maintenance requirements. This included the requirement for at least 25 hours of flight testing within a 35 NM (65 km) radius of Wedderburn Airport, New South Wales. Unusually, the SCOA was not limited by an expiry date.

An entry in the aircraft logbook on 12 November 2014 stated that the required 25 flight test hours were complete. Manoeuvres recorded as tested included 'loops, rolls, spins, half‑cuban eights, roll off the top of a loop, wingover and snaps [snap rolls]’. The SCOA flight test area was amended on 12 December 2014 to include Maitland Airport.

On 12 June 2015, SCOA Phase II replaced Phase I, authorising operation of an amateur-built aircraft in accordance with the Phase II limitations. These limitations restricted the conduct of aerobatic manoeuvres to those that had been flight tested.

Airworthiness and maintenance

The aircraft logbook statement required JDZ to be maintained under Civil Aviation Regulation 1988 (CAR) Schedule 5 and in accordance with the additional requirements of the annex to the SCOA. An annual inspection was to be carried out every 100 hours or 12 months, whichever came first. The last annual inspection was completed on 16 March 2015, and the associated maintenance release was valid at the time of the accident.

Uncertified maintenance

Maintenance carried out on an aircraft is required to be certified complete in accordance with CAR 42ZE and CAR Schedule 6. However, there were multiple maintenance actions carried out on JDZ that were not certified complete in the aircraft logbook. These included:

• a weld repair to the tail wheel post structure, including fabric replacement and rudder system removal and re‑fitment
• replacement of the original wooden propeller blades with composite blades^[3]
• replacement of engine oil and fuel delivery ‘flop tubes’^[4]
• replacement of the fuel quantity indicating system
• replacement of the tail wheel
• adjustment of the flying wires during the aircraft ‘flight test phase’.

Pilot maintenance

CASA authorised the holder of a private pilot licence to conduct certain maintenance as specified in CAR Schedule 8 (Schedule 8). In addition, CASA Instrument 33/13 Authorisation of persons to carry out maintenance on certain amateur‑built, kit-built and light sport aircraft with a special certificate of airworthiness detailed that, in some circumstances, a person who builds or has previously built an amateur‑built aircraft of a similar type, may be authorised to conduct certain maintenance and issue a maintenance release for that aircraft.

All maintenance conducted by a pilot under CASA Instrument 33/13 and/or Schedule 8 was required to be certified as per CAR 42ZE.

The occurrence pilot was authorised to conduct maintenance on JDZ as specified in Schedule 8. However, the pilot was not authorised to conduct maintenance on JDZ under Instrument 33/13 as they did not build the aircraft.

It was reported that the pilot replaced the tail wheel of JDZ due to excessive wear and shimmy. This maintenance action was permitted if carried out in accordance with Schedule 8. In addition, it was reported that adjustment of the aircraft flying wires, which was not included in Schedule 8, was carried out by another pilot during the Phase I flight testing period. Neither the tail wheel replacement nor the flying wire adjustments were certified in the aircraft logbook.

Maintenance of amateur-built aircraft

This and other ATSB investigations have identified a degree of uncertainty amongst a number of pilots and engineers regarding the certification of maintenance performed on amateur-built experimental aircraft. When asked, CASA advised that, in accordance with CASA Instrument 33/13, a licenced aircraft maintenance engineer (LAME) is authorised to certify for maintenance of certain amateur‑built, kit‑built and light sport aircraft with a SCOA. This authorisation extends to the scope and privileges of the LAME’s licence. Additionally, a LAME may certify for maintenance ‘for and on behalf of’ a maintenance organisation, if the aircraft undergoing maintenance is within the scope of activities for that organisation.

CASA also advised that other than a number of specific exemptions, amateur-built aircraft are to be maintained in accordance with the regulations and any additional instructions detailed in a SCOA annex. Ultimately, as per CAR 42CB Experimental aircraft, the certificate of registration holder is responsible for ensuring the aircraft is maintained in accordance with the regulations. In addition, CAR 133 Conditions of flight requires the pilot in command to ensure that all the required maintenance has been completed and is appropriately certified.

Weight and balance

An initial weight and balance was carried out on JDZ on 19 October 2006.

The ATSB estimated the aircraft’s weight and balance for the accident flight based on the available data. This indicated that the aircraft was likely operating within limitations at the time and the ATSB concluded that weight and balance was unlikely to be a factor in the loss of control.

Meteorological information

Witnesses described the weather at the time they observed JDZ as being calm with a clear sky.

Weather observations were recorded by an automatic station at the Maitland Visitor’s Centre. Observations for 1500 on 8 July 2015 recorded a temperature of about 15 °C, relative humidity of 60 per cent and a southerly wind at 6 km/h (about 3 kt). This was consistent with the witness observations.

According to the Geoscience Australia website (see www.ga.gov.au/), at about 1630 the sun was at an elevation of 5° above the horizon and an azimuth of 300°.^[5] The aircraft that was observed on primary radar, and the ATSB concluded to have been JDZ, was flying in an easterly direction just prior to disappearing from radar at about 1631 (see the section titled Radar and airspace information). The ATSB concluded that it was unlikely sun glare was a factor in the loss of control.

Communications

A review of the recorded Maitland common traffic advisory frequency^[6] broadcast data determined that the pilot transmitted a departure call on that frequency at 1609 local time. No further transmissions from JDZ were recorded.

Radar and airspace information

Aircraft transponder equipment

The aircraft logbook indicated that during the assembly, the aircraft was fitted with a Mode C transponder that could be activated by the pilot. There was no subsequent logbook entry in respect of the transponder.

Aeronautical Information Publication Australia^[7] EN ROUTE (ENR) 1.1 Section 56 OPERATING REQUIREMENTS FOR TRANSPONDERS, paragraph 56.1 stated that:

Pilots of aircraft fitted with a serviceable Mode 3A or Mode S transponder must activate the transponder at all times during flight, and if the Mode 3A transponder is Mode C capable, that mode must also be operated continuously.

In addition to the potential benefits to air traffic control of the activation of an aircraft’s transponder, aircraft traffic collision avoidance systems^[8] rely on transponder information for their traffic alerting and collision avoidance functions.^[9] These systems have the potential to enhance crews’ self separation, in particular in uncontrolled airspace.

Analysis of recorded radar data

The primary radar data for the aircraft that was manoeuvring in the area in which the pilot of JDZ was reported to regularly conduct aerobatics showed:

• an unidentified aircraft immediately to the south of Maitland Airport at about 1622
• from immediately south of the airport the aircraft tracked to the vicinity of the Keinbah Quarry
• the aircraft then tracked variously east and west for about 4 minutes
• the primary radar return for the aircraft was lost on two occasions and was reacquired after 23 and 10 seconds respectively
• the primary radar return for the aircraft was lost a third time at about 1631 and was not detected again.

Expert analysis of the aircraft’s radar data as it tracked variously east and west for 4 minutes indicated that the aircraft was manoeuvring consistent with the conduct of aerobatic manoeuvres.

In addition, the recorded flight path of a search aircraft with an operational transponder was also reviewed. The radar data from this aircraft showed that the:

• unidentified aircraft’s last detected location was consistent with the accident site
• primary surveillance radar could detect aircraft in that area down to an altitude of about 200 ft.

The ATSB concluded that, based on the analysis of the primary radar data, and its consistency with the witness observations, the unidentified aircraft was highly likely to have been JDZ. The ATSB could not determine whether the lack of a secondary surveillance radar return for JDZ was a result of the transponder not being activated or the equipment not operating correctly. Of note, secondary surveillance radar returns were observed for other aircraft in the area, indicating that terrain shielding was not a factor.

Airspace

• The Visual Terminal Chart^[10] for the area showed that JDZ was operating in uncontrolled, Class G airspace. This airspace, which extended up to an altitude of 8,500 ft, provided ample altitude in which to conduct aerobatic manoeuvres.

Site and wreckage information

Witness information

Witnesses reported that a loud engine noise caught their attention and caused them to look up to see JDZ near the top of what appeared to be a vertical climb. The aircraft was then observed to slide backwards tail first, before entering a flat spin. The flat spin descent was described as slow. Sight of the aircraft was lost behind trees and, shortly after, an explosion was heard by some witnesses.

Table 1 provides a summary of the observations that were unique to each witness. Figure 2 shows the location of each witness with respect to the accident site. Of the witnesses, witness D had flying experience.

Table 1: Summary of specific witness observations

Witness	Distance from the accident site	Witness-specific observations
A	1.75 km south	Aircraft ‘swooped side to side’ as it slid backwards, before entering an inverted flat spin.
B	2.9 km south	Observed in a nose-down attitude before sight was lost.
C	1.5 km north-west	Heard a loud bang after sight was lost.
D	1.75 km north-north-east	Reported that the engine sounded normal. The witness did not recall hearing the engine cut out or stall. After sight was lost, the witness heard a loud explosion, followed a few minutes later by a second explosion.

Figure 2: Witness location with reference to the accident site

Source: Google earth, modified by the ATSB

The area was reported to be popular with aerobatic pilots. The witnesses advised that they regularly observed various aerobatic manoeuvres by these aircraft.^[11] It was reported that the manoeuvres by the pilot of JDZ were, up to the point where sight was lost, consistent with the regularly-observed aerobatic manoeuvres.

The height of JDZ at the top of the vertical climb was estimated from the witness observations. While it could be expected that the accuracy of this estimation was affected by the witness’ limited visual references, observations from the three closest witnesses to the accident site suggested that the height of the aircraft at the top of the vertical climb was less than 2,000 ft above ground level.

Wreckage information

The accident site was about 8 km south-west of Maitland Airport and was located in thick bushland near the Hunter Expressway. Examination of the site and wreckage determined that immediately before colliding with terrain, the aircraft was inverted, slightly nose-down and in an almost vertical descent. An initial fuel-fed post-impact fire was followed by an intense oil-fed fire, which in combination destroyed most of the aircraft.

The aircraft structure was severely damaged by impact forces and the post-impact fire, limiting the evidence available and conclusions that could be drawn from an examination of the wreckage. However, that examination determined that:

• all components of the aircraft were located at the impact site
• there were no pre-accident defects with the aircraft and engine
• the cockpit canopy frame was consistent with it being in the closed position at the time of impact
• damage to the aircraft’s tubular structure was consistent with impact with trees and/or terrain
• what remained of the wooden wing spars showed little damage, consistent with little forward speed just prior to the impact with terrain
• the engine was partly submerged in the soft earth, at an angle of about 23° to the horizon
• continuity of engine controls was confirmed; however, the rest of the engine and its accessories were extensively damaged, or destroyed by the fire, preventing further assessment
• one propeller blade was torn from the hub and was wedged between the engine and the ground. The other blade was undamaged and had stopped in a vertical position. The positions of the propeller blades indicated that the engine rotated no more than a quarter turn following the impact with terrain.

Flight controls

The flight control system and cables were examined as far as possible. With the exception of the elevator control tube and hinge bolt, continuity of the flight controls was established on-site. A number of elevator and tail structure components were recovered for subsequent technical examination at the ATSB’s technical facilities in Canberra, Australian Capital Territory.

Technical examination of the recovered components determined that the fractures of the control tube and hinge bolt were consistent with overstress. No pre‑existing defects were identified and the failures were likely the result of impact with trees and/or terrain.

Seat harness and buckles

The webbing of both seat harnesses was almost entirely destroyed in the post-impact fire. Despite this level of damage, various buckles and harness adjust mechanisms were identified. Of these, one five-point harness buckle and one lap-belt harness buckle were found in the secured, or closed position. The other buckles were found unsecured (Figure 3). Refer to the section Test and research for more detail.

Figure 3: As-found five-point and lap-belt harness buckles. Of these four buckle sets, one of each type was secured (see the lower left and right images below)

Source: ATSB

Medical and pathological information

Post-mortem examination

The post-mortem examination identified that the pilot was fatally injured as a result of multiple injuries, consistent with an aircraft accident, and was deceased at the time of the post‑impact fire. The examination also identified significant coronary artery disease. Toxicology results were negative for alcohol and commonly-tested drugs.

Medical information

CASA records showed that the pilot had been monitored for borderline high blood pressure (hypertension) by the same Designated Aviation Medical Examiner (DAME) since January 2007. In this regard, the pilot had been taking anti-hypertensive medication as prescribed by his general practitioner (GP) since August 2012.This medication was permissible in accordance with the International Civil Aviation Organization Manual of Civil Aviation Medicine and was reportedly effective in maintaining the pilot’s blood pressure within prescribed limits.

The DAME and the GP advised that the pilot had not reported any side effects to the medication.

It was reported that the pilot also regularly took various herbal tonics that were dispensed by a naturopath. Additionally, the pilot was reported to use over-the-counter herbal supplements for relief from allergies, sinusitis and colds. The pilot did not report the use of these herbal supplements to their GP or DAME.

Civil Aviation Safety Regulations 1998 (CASR) 67.155 stated the criteria for medical standards for the holder of a private pilot licence. In particular, item 2.3 of the regulation required a pilot to not use:

…any over-the-counter or prescribed medication or drug (including medication or a drug used to treat a disease or medical disorder) that causes the person to experience any side effects likely to affect the person to an extent that is safety-relevant

As part of the initial issue and/or renewal of a medical certificate, any prescribed or over‑the‑counter medications taken for greater than 2 weeks (including herbal or alternative therapies) are to be documented. A review of the pilot’s CASA medical file showed that the anti‑hypertensive medication was the only medication noted.

The pilot was reported to be active and healthy. The DAME and GP advised they had no indication to suspect the pilot had significant coronary artery disease, as was identified by the post‑mortem examination.

It was reported that the pilot had been suffering from a head cold for at least a week prior to the accident. However, the severity of the symptoms could not be determined. In addition, the pilot had been heavily involved in the Hunter Valley Air Show over the period 4–5 July 2015. Reportedly this included preparations over several weeks, activities over the weekend and assisting with the post-event clean-up.

The pilot was reported to be well rested and in good spirits in the 2 days prior to the accident. There was insufficient evidence to indicate fatigue was a factor in the loss of control.

Nausea during aerobatic flying

It was reported that the pilot was affected by nausea during certain flying activities. Low g Load (g)^[12] tolerance and associated airsickness resulted in the pilot’s aerobatic training flights being kept brief or cut short on a number of occasions and with a number of instructors. Certain manoeuvres, such as spinning and negative g, reportedly affected the pilot more significantly than others. In addition, on more than one occasion during an aerobatic training flight, the nausea overwhelmed the pilot to the point where the instructor had to take control of the aircraft.

Civil Aviation Advisory Publication (CAAP) 155-1(0) Aerobatics provided detailed information on many aspects of aerobatics, including the physiological effects of g forces. Section 4.1 stated:

Aerobatic manoeuvres involve rapid changes in speed and direction which impose significant accelerative forces on the aircraft and pilot. The physiological effects of these G forces can range from minor discomfort to loss of consciousness.

Pilots beginning aerobatics may be adversely affected by airsickness, disorientation and discomfort but continued practice, and the use of appropriate methods of mitigating the physiological effects, will allow most pilots to adapt fairly quickly to standard aerobatic manoeuvres.

The CAAP also provided further and more-detailed information on the various g forces and their effects on the body. It described that pilots can build up their tolerance to g forces with practice but need to be aware that established tolerance levels can be significantly reduced by various factors that affect their physical condition. These factors included, but were not limited to, fatigue, illness, medication, low blood pressure and dehydration. In addition, lack of recent aerobatic practice will also reduce a pilot’s g tolerance and pilots returning to aerobatics after some time need to check and then gradually re-establish their tolerance level.

Section 4.20 Disorientation, included the following statement:

Sustained rapid rotation, such is in flick manoeuvres or spins, can also lead to disorientation because visual reference is made difficult due to the rapid rotation and there is no visual correction to the confused signals from the balance mechanism.

Recent ear, nose, throat infections may cause injury or pain, as well as disorientation, during aerobatics.

The pilot’s last recorded aerobatic training flight was 28 May 2015. Training notes for that flight indicated the pilot was unable to recover from a stable inverted spin. The pilot’s reported disorientation and nausea that day led to the decision to end the flight and return to the airfield.

Survival aspects

The pilot was not required to and did not notify a SARTIME,^[13] or leave a Flight Note with a responsible person. In addition, consistent with there being no need for the carriage in the aircraft of an ELT,^[14] the aircraft was not equipped with a permanent emergency locator transmitter (ELT). It was reported the pilot did carry a portable ELT but, only on extended cross‑country flights.

The pilot’s decision to not nominate a SARTIME or leave a Flight Note and not carry an ELT increased the risk of a delayed emergency response in the event of an accident or incident. However, in this case the accident was not considered survivable due to the magnitude of the impact forces and intensity of the post-impact fire.

Operational information

Low-level flying

The pilot in command must not fly the aircraft over non-built-up or –populous areas at a height lower than 500 ft unless it is within the exemptions detailed in CAR 157 (4) Low flying. Radar data showed JDZ below 200 ft on two occasions during the flight that day. There was no evidence to indicate any requirement, or authorisation for going below 500 ft during the flight.

Flying endorsements

The CASR Dictionary, Part 1 Definitions defined aerobatic manoeuvres as those that involve:

• bank angles that are greater than 60˚; or
• pitch angles that are greater than 45˚, or are otherwise abnormal to the aircraft type; or
• abrupt changes of speed, direction, angle of bank or angle of pitch.

A pilot was required to hold the appropriate aeroplane category and a spinning endorsement before an aerobatic endorsement was issued. In addition, the pilot was required to have received training and shown competency in all the course units mentioned in Part 61 Manual of Standards.^[15] That training included performance criteria covering loops, rolls, stall turns, recovery from unusual attitudes and spins. The knowledge requirements included, but were not limited to an understanding of the definitions of negative and positive g and the associated effects on the pilot and the aircraft.

CASR 61.065 prohibited the conduct of any activity for which the licence holder was not authorised. In addition, CASR subpart 61.S stated the requirements for aerobatic endorsements. These included that:

• an initial aerobatic endorsement would authorise the pilot to conduct aerobatic manoeuvres in an aeroplane above 3,000 ft above ground level (AGL)
• subsequent endorsements were necessary for aerobatic activities at lower altitudes.

Aerobatic flying

It was reported by a number of Pitts Model 12 pilots and instructors that:

• loops in a Pitts Model 12 aircraft usually required 1,000 to 1,500 ft to complete
• loops with a vertical consistency of around 1,500 ft would be required by the student to achieve aerobatic training competency
• aerobatic manoeuvres during training were normally commenced at 5,000 ft
• in all cases the loop should be entered and exited at the same altitude.

The height required to recover from a spin varies with pilot competency and experience. Spin recovery within the number of turns normally required for the aircraft type is essential to achieve basic competency. Early identification of the spin and correct control inputs should result in a prompt recovery.

The Pitts Model 12 pilot operating handbook Aerobatic Flight included, in part, that the pilot should:

…

-Do be certain that you have ample altitude for the maneuvers [sic] that you want to perform.

-Do be sure that you are familiar enough with the maneuvers [sic], and the airplane, that a bad recovery will produce no worse result than embarrassment.

-Know the limitation on your PITTS Model 12 and yourself.

In addition, the pilot’s operating handbook identified the procedures for emergency spin recovery as:

- POWER OFF

- REMOVE YOUR HAND FROM THE STICK

- DETERMINE DIRECTION OF SPIN ROTATION

- APPLY FULL OPPOSITE RUDDER

- WHEN ROTATION STOP [sic], RECOVER

Finally, CAAP 155-1(0) Aerobatics provided pilots with:

• information and guidance on safety issues related to aerobatic flight, including in respect of the aircraft, pilot and regulations
• an explanation of spin recovery techniques
• advice on the importance of ensuring sufficient height to recover from an aerobatic manoeuvre by 3,000 ft AGL (or the lower limit of the pilot’s approval). In particular, section 7.3.2 of the CAAP stated:

It is highly probable that the consequence of an error or failure during low-level aerobatics will be fatal to the participants.

Test and research

Unsecured seat harness

CAR 155 (5) Aerobatic manoeuvres required an unoccupied seat harness to be secured by the pilot in command prior to conducting an aerobatic manoeuvre. In addition, CAAP 155‑1 (0) Aerobatics discussed the importance of securing unoccupied seat harnesses to prevent them fouling the controls. The ATSB was advised that this procedure had been demonstrated to the pilot and that the pilot was aware of the associated regulatory requirement.

The ATSB determined that the pilot was secured in the rear seat harness and that the unsecured seat buckles were associated with the forward, unoccupied seat (see the previous discussion titled Site and wreckage information). Testing in a Pitts Model 12 aircraft determined that an unsecured forward seat harness had the potential to interfere with the aircraft’s flight controls. Figure 4 shows the orientation of the flight controls with reference to an unsecured forward seat harness.

Refer to appendix A Unsecured seat harness for more information.

Figure 4: Unsecured forward seat harness, showing the potential for the harness to interfere with the flight controls, in particular during aerobatic manoeuvres

Source: ATSB

ATSB research

ATSB research report AR-2007-043(2) Amateur-built aircraft, published 26 March 2013 and available at www.atsb.gov.au concluded the following in relation to amateur-built aircraft accidents:

• Between 1988 and 2010, amateur-built aircraft on the Australian VH-register had an accident rate three times higher than comparable VH-registered factory-built aircraft conducting similar flight operations.
• The fatal and serious injury accident rate was more than five-times higher in amateur-built aircraft than in similar factory-built aircraft.
• Loss of aircraft control led to 25 per cent of all amateur-built accidents, slightly more than for factory-built aircraft accidents. However, the loss of control accident rate was over four times higher. As compared to factory-built aircraft, serious injury was three times more likely after loss of control in amateur-built aircraft accidents.
• Loss of control accidents were more likely to arise from aircraft handling issues where pilots had comparatively lower levels of experience on the aircraft type.
• Loss of control was more likely to occur in the initial climb phase of flight.
• Amateur-built aircraft pilots were significantly more experienced overall than factory-built aircraft accident pilots. However, they were significantly less experienced on the amateur‑aircraft type being flown at the time of the accident when compared to pilots of factory-built aircraft accidents and amateur-built aircraft owners in general. Twenty per cent of amateur-built aircraft accident pilots had less than 10 hours experience on the accident aircraft type.

ATSB research report AR-2008-045 Improving the odds: Trends in fatal and non-fatal accidents in private flying operations, published in June 2010 and also available at www.atsb.gov.au identified that 44 per cent of all accidents and over half of fatal accidents between 1999 and 2008 were attributed to private operations. These figures far surpassed the proportions for any other flying category, even though private operations contributed to less than 15 per cent of the hours flown in that decade. The report also identified that:

• the three most common occurrence types in fatal accidents were collision with terrain, loss of control and wirestrike
• aircraft handling was a significant contributor to loss of control and collision with terrain fatal accidents
• compared with non-fatal accidents, fatal accidents were more likely to be associated with violations of rules and regulations. Violations of rules and regulations remove safety defences and, when coupled with an error, increase the likelihood of an accident.

Previous occurrences

ATSB investigations

The ATSB has investigated a number of fatal accidents involving the conduct of aerobatics. All are available via the ATSB website at www.atsb.gov.au.

199501051 – Collision with terrain involving Pitts S-2A, registered VH-IXY

On 8 April 1995 the pilot was observed practising aerobatic manoeuvres in a Pitts S-2A, registered VH-IXY. The early afternoon flight was observed from the ground by a number of other pilots, including a highly-experienced pilot and flying instructor. This pilot/instructor was in radio contact with the pilot.

The instructor reported a number of unusual manoeuvres by the pilot of VH-IXY and unsuccessful attempts by the instructor to contact the pilot. The aircraft then appeared to stabilise and the pilot responded saying he thought he might have blacked out. The aircraft landed normally and the pilot and instructor discussed g-induced loss of consciousness.

During a later aerobatic flight by the pilot of VH-IXY, after a period of standard aerobatic manoeuvres, the instructor on the ground observed the aircraft pitch up before commencing a continuous roll to the left. The instructor made several unsuccessful attempts to contact the pilot by radio. The nose of the aircraft dropped and the aircraft dived almost vertically into the ground.

The pilot was fatally injured and the aircraft destroyed.

AO-2014-114 - Collision with terrain involving DHC-1 Chipmunk, registered VH-UPD

The ATSB also investigated the collision with terrain involving a DHC-1 Chipmunk, registered VH‑UPD, which occurred near Coffs Harbour, New South Wales on 29 June 2014.The passenger and witness reports indicated that, during an attempted aerobatic manoeuvre, the aircraft entered a spin. The pilot had reportedly received some aerobatic training but had yet to receive an endorsement. Video footage taken by witnesses showed the aircraft established in a slow, upright spin. The on‑site evidence was consistent with the spin continuing until the impact with terrain. The ATSB found it was likely the pilot did not possess the necessary skills and judgement to conduct the manoeuvre safely and consistently.

AO-2014-163 - Collision with terrain involving amateur-built aircraft, registered VH-EGT

On 10 October 2014, the pilot of an amateur-built One Design DR-107 aircraft, registered VH‑EGT, was observed performing a series of low-level aerobatic manoeuvres. Each involved a vertical climb and tumbling manoeuvre followed by a vertical dive and a low altitude recovery. Witnesses reported that, during recovery from the last vertical dive, the aircraft collided with terrain. The aircraft was destroyed by the impact and the pilot was fatally injured.

There was insufficient evidence to determine why the recovery was not accomplished above the pilot’s minimum‑authorised aerobatics height. The accident highlighted the risks inherent in performing low-level aerobatics and the ATSB encouraged pilots to always maintain minimum approved heights above the ground when performing aerobatics.

United States National Transport Safety Bureau investigations

A review of the United States National Transportation Safety Board (NTSB) Aviation Accident Database identified two accidents involving Pitts Model 12 aircraft losses of control and one regarding possible pilot impairment that showed similar traits to the ATSB’s investigation of the accident involving JDZ. Below is a brief summary of the NTSB’s investigation reports into these accidents (available at NTSB website).

Loss of control accidents

NTSB investigation report MIA00LA149 involved a collision with terrain of a Pitts Model 12 on 9 May 2000, with both occupants fatally injured. It was reported the pilot had been flying in formation, but discontinued the return flight to practice aerobatics. Examination of the wreckage showed extensive damage consistent with the aircraft impacting the hard ground inverted, in about a 20°–25°nose‑low attitude. The NTSB determined the ‘probable cause’ of the accident as ‘the pilot’s loss of control in flight for undetermined reasons’.

NTSB investigation report ANC05LA033 found that a Pitts Model 12 collided with terrain while the pilot was performing low‑altitude aerobatic manoeuvres on 12 February 2005. Site and wreckage examination concluded that all damage was consistent with the aircraft impacting the ground in a near-vertical descent. The NTSB determined the ‘probable cause’ of the accident as:

The pilot’s failure to maintain control of the airplane while performing a low altitude, aerobatic maneuver [sic], which resulted in an uncontrolled descent, and an in-flight collision with terrain. A factor associated with the accident was the initiation of a low altitude aerobatic manoeuvre.

Pilot impairment

NTSB investigation report CEN11LA582 found that ‘the pilot’s impairment during an aerobatic airshow performance for reasons that could not be determined…resulted in an in-flight loss of airplane control’. The report identified the pilot had previously sought treatment for vertigo and nausea suffered while conducting aerobatics.

United Kingdom Air Accidents Investigation Branch investigation

The United Kingdom Air Accidents Investigation Branch^[16] published investigation report EW/G2009/05/11 regarding a collision with terrain involving a Pitts S-12 that occurred on 14 May 2009. The pilot was the sole occupant and received serious injuries. The report ‘emphasised the importance of entering a manoeuvre at a height from which recovery was possible in the event of failure to complete it as planned’. Additionally the report referred to the summary of British Aerobatic Association Safety Sense Leaflet 19 Aerobatics, which stated:

…start with sufficient height to give plenty of margin if things go wrong

__________

3. Replacement of the blades was entered in the aircraft logbook, but the entry did not include the associated release and traceability documentation required by CAR Schedule 6. In addition, the registration details and logbook statement had yet to be updated with the new propeller information.
4. A flop tube is a flexible hose with a weighted end. The weight ensures the hose draw point remains submerged in the respective fluid whether the aircraft is in normal or inverted flight.
5. The clockwise horizontal component of the sun’s or moon’s position from true north, measured in degrees.
6. Common Traffic Advisory Frequency is the frequency on which pilots operating at a non-towered aerodrome should make positional radio broadcasts.
7. A package of documents that provides the operational information necessary for the safe and efficient conduct of national (civil) and international air navigation throughout Australia and its Territories.
8. An aircraft collision avoidance system that monitors the airspace around an aircraft for other aircraft equipped with a corresponding active transponder and gives warning of possible collision risks.
9. AIP ENR 1.6 Section 7.1 Operation of SSR Transponders, paragraph 7.1.2.
10. Visual Terminal Charts provide aeronautical and topographical information for operations under the Visual Flight Rules in the vicinity of major aerodromes. They also show controlled airspace.
11. Witness simulations of their observations with an aircraft model were consistent, even when unsure of the correct manoeuvre terminology.
12. g Load is the nominal value for acceleration. In flight, g load values represent the combined effects of flight manoeuvring loads and turbulence. This can be a positive or negative value.
13. The time nominated by a pilot for the initiation of search and rescue action if a report has not been received by the nominated unit.
14. Crash-activated radio beacon that transmits an emergency signal that may include the position of a crashed aircraft. Also able to be manually activated.
15. The purpose of Part 61 Manual of Standards Instrument 2014 is to set out the standards relating to flight crew licensing.
16. AAIB reports can be viewed via https://www.gov.uk/government/organisations/air-accidents-investigation-branch.

Appendices

Appendix A – Unsecured seat harness

Examination of seat harness components

The aircraft was fitted with two seats to accommodate a passenger forward and the pilot aft. Both seats had a five‑point harness and a lap-belt harness. The dual harness arrangement is typical for aerobatic aircraft. The five-point and lap-belt harnesses are secured to separate airframe attachment points. In addition, the buckles of each harness type operate in opposite directions to minimise the risk of accidental release. It was reported that VH-JDZ had the same type of harness in the forward and rear seats.

The various secured and unsecured harness buckles located on site were retained for further examination.

Forward five-point harness

The lever mechanism of the unsecured forward five-point buckle was observed to be in the closed position; however, it could not be determined if this lever was in the closed position during flight or as a result of the impact with terrain. It was noted, however, that all five buckle components were separate from each other, consistent with the buckle assembly not being secured or closed. Visual examination of the unsecured five-point buckle components did not identify any deformation or damage. In addition, when tested, the buckle mechanism was capable of operation and security.

Rear harness

The rear pilot shoulder harness restraint cable that connected it to the airframe structure had fractured in overload. The tubular structure to which the rear pilot crotch strap was secured had fractured at each end of the tube, where it is welded to the airframe structure. In addition, components of the ‘secured’ rear five-point harness buckle showed signs of deformation (Figure A1).

Figure A1: Deformation to rear seat buckle in comparison with the forward buckle, and fracture of rear seat crotch strap hard point

Source: ATSB

Conclusion

Damage to the airframe and the severed harness cable at the rear pilot position was consistent with the pilot being secured in the seat at the point of impact. Therefore, the open buckles of the five point harness and lap belt were associated with the unoccupied, forward passenger seat.

Unsecured harness testing

Civil Aviation Regulation 155 (5) Aerobatic manoeuvres required an unoccupied seat harness to be secured by the pilot in command prior to conducting an aerobatic manoeuvre. In addition, Civil Aviation Advisory Publication 155‑1 (0) Aerobatics indicates that unoccupied seats should have their harnesses secured to prevent them fouling the controls.

In the Pitts Model 12 the harnesses can be secured by connecting the buckles, pulling the adjustment straps tight, wrapping the adjusting lengths round the bundle and tucking in the loose ends. The ATSB was advised that this procedure was demonstrated to the pilot and that the pilot was aware of the need to secure the seat harnesses.

The ATSB conducted testing in a Pitts Model 12 aircraft to ascertain if unsecured forward seat harness components had the potential to interfere with the aircraft’s flight controls.

The rear pilot’s rudder pedals are positioned on either side of the forward seat base. A loose lap strap and associated buckle, from either the forward seat lap belt or five-point harness, were found to have the potential to interfere with rudder pedal operation. In addition, a buckle component could lodge between the rudder pedal and the diagonal tubular bracing of the airframe (Figure A2).

Figure A2: Possible rudder pedal interference from an unsecured forward seat harness

Source: ATSB

Access to the rudder pedals from the rear seat was limited and it would be very difficult to release a misplaced front seatbelt by hand. Also, due to the design of the rudder control system, rearward movement of one rudder pedal does not naturally impart a forward movement of the opposite pedal.^[17] Therefore, the cockpit layout and rudder design may inhibit the pilot’s ability to free an obstructed rudder pedal in flight.

It was also noted that it was possible for the forward seat crotch strap and associated buckle to interfere with the forward seat elevator control stick (Figure A3). It would not be possible for a rear‑seat pilot to remove this obstruction by hand during flight operations.

Figure A3: Possible elevator control interference from an unsecured forward seat harness

Source: ATSB

__________

17. Also known as an ‘open loop control’.

Findings

From the evidence available, the following findings are made with respect to the collision with terrain involving a Pitts Model 12, registered VH-JDZ, which occurred about 8 km south-west of Maitland Airport, New South Wales on 8 July 2015. These findings should not be read as apportioning blame or liability to any particular organisation or individual.

Contributing factors

• Control of the aircraft was lost during a vertical manoeuvre that was likely entered at an altitude lower than that required and the aircraft was not recovered before impact with terrain.

Other factors that increased risk

• The pilot conducted low-level flight and aerobatic manoeuvres despite not holding the appropriate authorisations, significantly increasing the risk of an accident.
• The pilot used non-prescribed medication and herbal supplements without informing their doctor and Designated Aviation Medical Examiner, removing a protection against pilot incapacitation.
• Uncertified and unauthorised maintenance was carried out on VH-JDZ, which increased the risk that a technical issue would affect the safety of the aircraft and those on board.
• Industry interpretation of the regulations regarding the maintenance of amateur-built experimental aircraft was varied, increasing risk associated with the maintenance of those aircraft.

Other findings

• The front seat buckles were found unsecured and, although unable to be determined if they were not secured correctly as part of the standard pre-flight preparation for solo flight, or they may have undone as a consequence of the impact sequence, any insecurity during aerobatic manoeuvres has implications for flight control fouling.

The occurrence

At about 1618 Eastern Standard Time (EST)^[1] on 8 July 2015, the pilot/owner of an amateur-built Pitts Model 12, registered VH-JDZ (JDZ), departed Maitland Airport, New South Wales on a local flight. The aircraft was being operated in the experimental category and the pilot was the only person on board.

JDZ was fitted with a transponder^[2] however, the aircraft was not detected by secondary radar. The lack of a secondary surveillance radar return was consistent with either the transponder not being activated or, if activated, the equipment not operating correctly (see the section titled Radar and airspace information). However, primary surveillance radar detected an aircraft at about 1622, to the south of Maitland Airport. The location and movements of this aircraft were consistent with the area in which the pilot of JDZ was reported to regularly conduct aerobatics (see the following discussion).

The primary radar data indicated that the aircraft initially flew in a south-easterly direction, before heading west toward an area near Lovedale Road and Keinbah Quarry. The aircraft then tracked variously east and west, consistent with the conduct of aerobatic manoeuvres. The aircraft disappeared from radar before reappearing on two occasions during the flight. At about 1630 the aircraft disappeared from radar a third time and was not detected again.

Witnesses reported that the area in which they saw the aircraft leading up to the accident is regularly used for aerobatics. Several witnesses reported hearing a particularly loud engine sound at about 1630 that caught their attention. Witnesses described:

• the aircraft at the top of what appeared to be a vertical climb
• the aircraft sliding backwards, tail first, before entering a flat spin
• that the flat spin descent was slow and almost straight down, with little forward speed
• that the aircraft completed several rotations during the spin before sight was lost behind trees.

Three of the witnesses believed the aircraft had impacted terrain and contacted the police. At about 1650 emergency personnel arrived in the area and commenced a ground search. At the same time, a number of aircraft from Maitland Airport commenced an aerial search. A rescue helicopter was also dispatched.

The aircraft was located from the air at about 1712 and ground crews arrived at the site shortly after. The aircraft had collided with terrain in thick bushland in the area in which aircraft regularly conducted aerobatics and close to where the previously-discussed aircraft disappeared from primary surveillance radar. The pilot was fatally injured and there was an intense post‑impact fire. The fire could not be extinguished with the available resources and was monitored until it self‑extinguished (Figure 1).

Figure 1: Accident site viewed from the front of the aircraft and showing the surrounding thick vegetation and minimal structural damage to the wings and airframe (consistent with the reported vertical descent)

Source: ATSB

__________

1. Eastern Standard Time (EST) was Coordinated Universal Time (UTC) + 10 hours.
2. A radio device that, when triggered by the correct radio signal (called interrogation), transmits a pre-coded reply. Air traffic control ground equipment interrogates the aircraft’s transponder, identifies the aircraft by its reply code and displays the aircraft’s position on the controller’s radar screen.

Purpose of safety investigations & publishing information

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through: identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

The aircraft departed Newcastle Airfield (EINC), County Wicklow, Ireland, with two pilots on board. The intention was to perform a short flight before returning to Newcastle Airfield. Approximately 20 minutes into the flight, a small amount of blue smoke was noticed in the cockpit, followed by a loss of engine oil pressure. The pilot decided to carry out a forced landing and a suitable field was selected. To prevent engine damage, the pilot shut down the engine during the approach to the chosen field. The aircraft landed and came to rest without further incident. There were no injuries and the aircraft was undamaged. Subsequent examination revealed that a hose supplying engine oil to the engine oil cooler had disconnected in flight, resulting in the loss of all engine oil. The aircraft was fitted with a Jabiru 2200A engine.

As the accident occurred in Ireland, the Air Accident Investigation Unit (AAIU) Ireland is responsible for investigating this occurrence. As part of its investigation, the AAIU requested assistance from the Australian Transport Safety Bureau (ATSB) as the State of Manufacture of the engine. In accordance with chapter 5.18 of Annex 13 to the Convention on International Civil Aviation, the ATSB appointed an accredited representative to assist the AAIU and initiated an investigation (AE-2015-051) under the Australian Transport Safety Investigation Act 2003.

The AAIU investigation has been completed and the final investigation report is available from the AAIU website at www.aaiu.ie.

The report contains two recommendations for Jabiru Aircraft Pty Ltd:

1. Jabiru Aircraft Pty Ltd should include a warning in the Instruction and Maintenance Manuals for the Jabiru 2200 engine and similar Jabiru engine types, highlighting that if oil cooler hoses are installed with oil on the hose fittings or, with oil on the inside of the hose in the vicinity of the fittings, hose security may be adversely affected.
2. Jabiru Aircraft Pty Ltd should, with the aid of a suitable publication, promulgate de-identified details of the subject event to users of its engines.

In accordance with Chapter 6.12 of Annex 13 to the Convention on International Civil Aviation, Jabiru Aircraft Pty Ltd have advised the ATSB that they have communicated the following actions to the AAIU:

Jabiru Aircraft Pty Ltd released Service Letter (JSL018) on 1 October 2015 as an informational letter on the subject of oil cooler hoses applicable to all Jabiru engines. Additionally, the following text has been added to Installation Manuals JEM3302-6 and JEM2202-8, and Maintenance Manual JEM0002-6:

‘Note: If oil cooler hoses are installed with oil on the hose fittings or, with oil on the inside of the hose in the vicinity of the fittings, hose security may be adversely affected.’

 

Arrivals radar was being operated by a trainee controller under the supervision of a rated controller. VH-ANJ and VH-FKI were both tracking to Perth via Clackline. The trainee controller had given both heading and altitude instructions to the aircraft in an attempt to manage their separation. A breakdown in separation standards occurred when the aircraft approached to within 3 nautical miles and 500 feet vertically before the instructions took effect. The supervising controller took over and provided VH-FKI with traffic information on VH-ANJ which allowed visual separation to be maintained.

Although the trainee controller recognised that there would be a separation problem the instructions given to the aircraft were not given in time nor were they sufficient to separate the aircraft under all possible conditions.

The supervising controller was slow to take control of the situation because he wished to give the trainee, who was at an advanced stage of training, the opportunity of recognising the situation and making the necessary corrections.

The trainee's task was made more difficult when VH-FKI did not descend as early as anticipated and drifted to the right of the runway 24 localiser, and towards VH-ANJ, after the pilot had reported established.

The following factors led to the development of this occurrence.

1. The trainee controller did not have sufficient expertise to be able to recognise and allow for all possible variables in the traffic conflict situation.

2. The supervising controller made an error of judgement when he delayed his intervention and was unable to prevent the breakdown in separation standards.

3. Whilst not a direct factor, the flight path of VH-FKI complicated the situation.

VH-FCE departed Coffs Harbour for Williamtown at 1237 ESuT and was maintaining 10,000 ft with an estimate for Taree of 1307.

VH-TQQ departed Sydney for Port Macquarie at 1231 and passed over Williamtown at 1252 while cruising at FL170 with estimates for Taree of 1307 and Port Macquarie 1314. Air traffic control (ATC) cleared VH-TQQ to leave the control area on descent and at 1305 VH-TQQ reported leaving FL170 and was instructed to contact Sydney on the area frequency.

At 1306 VH-TQQ made an all stations call on area frequency and reported having left FL170 on descent to Port Macquarie. The flight service officer (FSO) notified VH-TQQ of the Area QNH and advised that there was no IFR traffic. At 1308 the FSO advised VH-TQQ that there was traffic at 10,000 ft and the crew replied they had just sighted VH-FCE while passing through that aircraft's level.

During the subsequent investigation, the crew of VH-TQQ stated that they were descending at 1700 ft/min and were approximately 1 NM east of track. While conducting a normal lookout scan, they sighted VH-FCE approximately 1 to 2 NM to their left and an estimated 2,000 ft to 3,000 ft below.  As they could maintain visual contact, they decided that no evasive action was needed. The captain stated that had he received traffic information on VH-FCE he would have levelled off above 10,000 ft until positive passing had been established.

The crew of VH-FCE stated that they were on track and over Taree when they sighted VH-TQQ descending from approximately 1,000 ft above and 2 NM left of their aircraft. They confirmed that they heard VH-TQQ make the area transmission and were looking out for the aircraft but decided it was not necessary to respond to this transmission. They also decided that as they could see the aircraft no evasive action was necessary.

The FSO's evaluation of the situation was influenced by the phraseology used by the Sector 2 controller who indicated to the FSO that VH-TQQ would call requesting traffic information on area frequency at top of descent. The FSO had sufficient information on hand to alert both aircraft. However, when VH-TQQ called at 1306 she calculated that the time of passing would occur at 1307 and that in this time period VH-TQQ would not have descended 7,000 ft. Based on this assessment the FSO chose not to pass traffic information to the two aircraft.

CONCLUSION

Significant Factors

The following factors were considered relevant to the development of the incident.

1. The FSO incorrectly assessed a traffic conflict situation and did not pass traffic information to the crews of VH-TQQ and VH-FCE.
2. The co-ordination procedures used between ATC and FS contributed to the FSO's incorrect assessment.
3. The crew of VH-FCE had prior knowledge of the presence of VH-TQQ but decided not to respond toVH-TQQ's descent call.

SAFETY ACTION

As a result of the Bureau's investigation the Civil Aviation Authority, inter alia, reviewed the phraseologies used between Air Traffic Control and Flight Service in relation to aircraft proceeding into or out of controlled airspace.

During the take-off roll all engine indications were normal. However, shortly after liftoff the pilot noted that engine RPM was decreasing. Efforts to restore power were not successful, and the pilot was committed to a forced landing on rough terrain beyond the end of the flight strip. During the landing roll the left main landing gear was dislodged, and a fuel tank was ruptured. Fire broke out and destroyed the aircraft.

The subsequent examination of the wreckage was hampered because of the extensive fire damage. The only abnormality discovered was that those spark plugs which could be removed from the engine showed signs of being exposed to an over-rich fuel/air mixture. The fire damage to the relevant engine systems prevented the reason for this condition from being positively determined.

Shogun and Pirate sections [2 X FA 18] were operating at Flight Level 310 in the Mudgee/Cowra area when VHF communications became poor and, at times, impossible. As a result, Sydney air traffic control were unable to pass traffic alerting information for the descent phase of the operation.

Subsequent communications were established during the descent and there was no breakdown in separation.

VH-HYB, on track between Mildura and Griffith, en route to Sydney, was maintaining non-standard Flight Level 380. The non-standard level was approved by air traffic control to help the aircraft avoid turbulence. UTA 147, flying on the same track in the opposite direction was maintaining Flight Level 350 but requested a climb to Flight Level 370. This request was immediately approved by air traffic control Sector 4. An adjacent controller noticed the altitude readout on UTA 147 as Flight Level 363 when both aircraft were about 10 nautical miles apart nose to nose.

He immediately called out to the Sector 4 controller who was engaged in coordination. Before the UTA 147's altitude clearance could be amended to Flight Level 360, to achieve the required 2000 feet vertical separation, the pilot of UTA 147 read back "maintaining Flight Level 370". The controller immediately attempted to pass traffic information to UTA 147 but because of language difficulties, the information was not understood before both aircraft had passed with the reduced separation of 1000 feet.

VH-NID [DHC8] had departed Sydney for Port Macquarie and was maintaining Flight Level [FL]170 and passed Williamtown at 2139 estimating Port Macquarie at 2202 hours [All times are UTC].

VH-RUI [PA31] taxied at Port Macquarie for Williamtown at 2149 hours and was passed traffic on VH-NID by Sydney Flight Service [FS]. At 2150 hours VH-NID called on area frequency and reported leaving FL150 on descent with a circuit estimate for Port Macquarie of 2159 hours. FS passed traffic on VH-RUI to VH-NID informing the crew that VH-RUI was taxiing and would climb to 6000ft.

At 2151 hours VH-RUI gave his departure call on area frequency as time 50 and climbing to 6000ft.

No further calls were made by either crew until 2157.30 hours when VH-NID advised on area frequency that he was changing to MTAF and asked Sydney to confirm the altitude of VH-RUI as 2000ft. VH-RUI advised that he was maintaining 6000ft. Interviews confirm that the incident occurred approximately one minute prior to this transmission.

Both crews agree that the occurrence was approximately 15-20nm south of Port Macquarie and the Automatic Voice Recorder [AVR] analysis, when combined with pilot reports, put the time of passing at between 2156.30 and 2157.00 hours.

The pilot of VH-RUI stated that he first saw VH-NID descending in front of him and about 300ft above, causing him to take violent evasive action.

The crew of VH-NID stated that they saw VH-RUI about 1000m to their left when approaching 7000ft and therefore had no need to limit their descent.

Both crews were given traffic information on each other in a correct and timely manner and stated that they were on track.

The weather was fine with no cloud.