Aviation safety investigations & reports

Wirestrike involving a Robinson R44, VH-ZWK, 20 km from Naracoorte, South Australia, on 13 March 2019

Investigation number:
AO-2019-011
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

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What happened

On 13 March 2019, a Robinson R44 helicopter, registered VH-ZWK and operated by Helifarm, was conducting aerial spraying operations at Bool Lagoon, around 20 km south of Naracoorte, South Australia.

While spraying along a drainage channel, the helicopter pilot momentarily forgot about the location of a powerline spanning the channel, as he manoeuvred the helicopter over a bridge. The helicopter collided with the powerline, then crashed into the ground. The helicopter was destroyed and the pilot sustained minor injuries.

What the ATSB found

The helicopter pilot momentarily lost awareness of the powerline as he manoeuvred over the bridge. Nearby vegetation, which reduced the pilot’s ability to see the power poles and visually identify the powerline, probably reduced the pilot’s ability to maintain this awareness. The operator had a number of policies and procedures to support pilots’ powerline awareness, and it may not be possible to completely mitigate the risk of wirestrike during repeated low-level flying near powerlines.

As a result of this momentary loss of awareness, the helicopter collided with the powerline, which led to a collision with terrain. The bladder-type fuel tank installed in the accident helicopter, as compared to an all-aluminium fuel tank, probably reduced the risk of a post-accident fire.

What's been done as a result

The operator has implemented new policies and procedures to increase pilots’ awareness of powerlines during spraying operations, particularly spraying of drains. These include improved maps and other planning documents for drain spraying operations involving flying near powerlines, and increased training of helicopter pilots engaged in these operations.

Safety message

This accident provides another reminder of the dangers posed by powerlines during low-level spraying operations.

The ATSB has released, in association with the Aerial Application Association of Australia (AAAA), an educational booklet, Wirestrikes involving known wires: A manageable aerial agriculture hazard (AR-2011-028). This booklet contains numerous wirestrike accidents and lessons learned from them. The AAAA has now launched its Powerline Safety Program that aims to encourage and facilitate power companies to improve aviation safety. The program includes marking of powerlines by powerline network operators (with a marker in accordance with Australian Standard AS 3891-2) wherever it is requested by a pilot, aviation company or landholder.

As this accident highlights, there may be limits to the extent to which operators can mitigate the risk of wirestrike during repeated low-level operations near powerlines. Helicopter wirestrike protection (WSPS) can provide a last line of defence in the event of a wirestrike. Some aircraft selected for aerial agriculture operations can be configured to include WSPS. However, this technology is not currently available on smaller helicopters such as the R44.

Pilots and operators involved in low-level spraying are also reminded that flight helmets can reduce the risk of serious injury in the event of an accident.

Download final report
[Download  PDF: 626KB]
 
 
 

The occurrence

Safety analysis

Findings

General details
Date: 13 March 2019   Investigation status: Completed  
Time: 1428 ACDT   Investigation level: Short - click for an explanation of investigation levels  
Location   (show map): 20 km south of Naracoorte (Bool Lagoon)   Investigation phase: Final report: Dissemination  
State: South Australia   Occurrence type: Wirestrike  
Release date: 28 June 2019   Occurrence category: Accident  
Report status: Final   Highest injury level: Minor  

Aircraft details

Aircraft details
Aircraft manufacturer Robinson Helicopter Co  
Aircraft model R44  
Aircraft registration VH-ZWK  
Serial number 1994  
Operator Helifarm Pty Ltd  
Type of operation Aerial Work  
Sector Helicopter  
Damage to aircraft Destroyed  
Departure point Bool Lagoon, South Australia  
Destination Bool Lagoon, South Australia  
Last update 16 July 2019