Aviation safety investigations & reports

Engine power loss and collision with terrain, Bell 206B3 helicopter, VH-FHW 107 km south-west of Jabiru, Northern Territory, on 21 May 2019

Investigation number:
AO-2019-025
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final report

Download Final report
[Download  PDF: 2.86MB]
 

What happened

On 21 May 2019, while engaged in a planned cull of feral animals in Kakadu National Park, Northern Territory, a crew of three were using a Bell 206B3 JetRanger helicopter for aerial platform shooting. While the helicopter was operating at about 50 ft above the ground, the engine decelerated to idle, resulting in an immediate loss of power, and subsequent collision with terrain. The three occupants (pilot, shooter and spotter) were seriously injured.

What the ATSB found

The engine power loss was due to a leak created by a loose union on an engine reference air line. During maintenance 4 days prior to install a power turbine governor (PTG), the union, which was downstream of the work completed, had not been checked for tightness. Potentially associated with distractions in the hangar at the time, an independent inspection following installation of the PTG was probably not conducted, and document verification processes did not detect that the independent inspection had not been recorded.

The cabin was not well prepared for the subsequent collision with terrain, with a range of factors exacerbating the occupants’ injuries or increasing risk. For example, the Director of National Parks required shooters and spotters to wear helmets, but helmets were not provided or used on a routine basis. Safety issues were also identified with the ambiguous wording of the instrument permitting harness use (issued by the Civil Aviation Safety Authority), and renewal of aerial platform shooting approvals without recurrent emergency training.

Additionally, the ATSB found that the Director of National Parks did not actively manage the risk of the aerial culling task, or effectively supervise the operation. As a result, an increase in the number of crew, a change in helicopter type and change of helicopter operator all progressed without requisite risk management. This exposed crew to avoidable harm during low-level aerial shooting operations.

What has been done as a result

The operator ordered an immediate fleet wide check of the security of all flexible and rigid reference air lines in its engines. Additionally, the approved maintenance organisation improved delivery of human factors training for engineers by contracting an external provider to deliver the course.

The Civil Aviation Safety Authority (CASA) has planned action to resolve the ambiguity associated with the instrument permitting harness use, and to require operators to ensure task specialists are trained in normal and emergency procedures. In addition, the operator has taken action to ensure all crew members are aware of the risk associated with using only a harness instead of a seat belt.

The Director of National Parks (DNP) immediately suspended aerial culling activities. In December 2019, the DNP commenced an internal review of standards of practice relating to aerial culling activity and personal protective equipment, and reaffirmed its requirement for the use of helmets during any future culling activities. The DNP has also undertaken a specialist aviation safety review into its aerial culling operation and is conducting ongoing review of its risk management policy and related aspects.

Safety message

Assured airworthiness and preparation of aircraft operating at low-level is paramount. Knowing that maintenance activities carry risk of error, independent inspection is a vital risk control. Inspections must be designed and conducted in a way that will capture critical issues, and visual inspections will not always be enough.

Any organisation that requires staff to engage in high-risk aviation activities should obtain professional advice on task design, actively manage risk, and provide appropriate equipment.

Download Final report
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The occurrence

Context

Safety analysis

Findings

Safety issues and actions

Sources and submissions

Safety Issues

Go to AO-2019-025-SI-01 - Go to AO-2019-025-SI-02 - Go to AO-2019-025-SI-03 - Go to AO-2019-025-SI-04 - Go to AO-2019-025-SI-05 -

Helmet provision and use

Although the Director of National Parks’ safe operating procedures required shooters and spotters to wear helmets during aerial culling tasks, helmets were not provided or used on a routine basis.

Safety issue details
Issue number: AO-2019-025-SI-01
Status: Open – Safety action pending

The Director of National Parks' risk management

The Director of National Parks did not actively manage the risk of the aerial culling task being conducted in the Kakadu National Park, or effectively supervise the operation. As a result, an increase in the number of crew, a change in helicopter type and change of helicopter operator all progressed without requisite risk management. This exposed crew to avoidable harm during low-level aerial shooting operations.

Safety issue details
Issue number: AO-2019-025-SI-02
Status: Open – Safety action pending

Aerial platform shooter emergency training

Recurrency training and drills in aircraft emergencies were not required for reissue of an aerial platform shooting permission. Some shooters last conducted training about 20 years prior, during initial issue of their permissions.

Safety issue details
Issue number: AO-2019-025-SI-03
Status: Open – Safety action pending

Harness instrument clarity

A harness instrument, commonly issued by the Civil Aviation Safety Authority (CASA), stated that a harness could be used instead of a seatbelt for take-off and landing. Although not intended by CASA, this instrument was easily able to be misinterpreted as indicating that a seatbelt was not required to be used during take-off and landing.

Safety issue details
Issue number: AO-2019-025-SI-04
Status: Open – Safety action pending

Crew risk awareness

Although required by the harness instrument commonly issued by the Civil Aviation Safety Authority, the operator did not appraise shooting crews of the risks of using only a harness for restraint during low-level flight.

Safety issue details
Issue number: AO-2019-025-SI-05
Status: Closed – Adequately addressed
General details
Date: 21 May 2019   Investigation status: Completed  
Time: 10:30 CST   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): 107 km south-west of Jabiru   Investigation phase: Final report: Dissemination  
State: Northern Territory   Occurrence type: Collision with terrain  
Release date: 26 February 2021   Occurrence category: Accident  
Report status: Final   Highest injury level: Serious  
Anticipated completion: 1st Quarter 2021    

Aircraft details

Aircraft details
Aircraft manufacturer Bell Helicopter Co  
Aircraft model 206B  
Aircraft registration VH-FHW  
Serial number 2838  
Operator Jayrow Helicopters  
Type of operation Aerial Work  
Sector Helicopter  
Damage to aircraft Substantial  
Departure point Unknown  
Last update 26 February 2021