Aviation safety investigations & reports

Collision with terrain involving AS350, VH-SZS, 60 km east of Woomera, South Australia, on 20 March 2019

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

Final Report

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[Download  PDF: 1.67MB]

What happened

On 20 March 2019, the pilot of an Airbus Helicopters AS350B3e, registered VH-SZS (SZS) was performing aerial work on Pernatty Station, South Australia, approximately 60 km east of Woomera Airfield. The task involved helicopter powerline stringing from the Mount Gunson South substation to the Carrapateena mine site, a total distance of 51 km. The stage being conducted on the morning of 20 March was from pole 159 to pole 179, a distance of 4.8 km. Stringing operations continued normally for poles 161, 162 and 163. However, while approaching pole 164, at about 1017, witnesses reported seeing the helicopter collide with the pole and impact terrain near the base of the pole. The pilot, who was the sole occupant, received fatal injuries.

What the ATSB found

The ATSB found that shortly after the pilot was trained in powerline stringing, for unknown reasons they modified the taught stringing methodology. The new methodology placed the helicopter at low level in the vicinity of the powerline poles, increasing the risk of a collision. It also exacerbated the uptake of dust which, in combination with the position of the sun and the rearward attitude of the aircraft likely reduced the pilots’ visibility of pole 164 and their situational awareness of it.

These factors, combined with the short distance and large elevation gain between pole 163 and 164, led to the pilot inadvertently colliding with pole 164. It was also found that the indirect supervision provided to the newly trained pilot was ineffective in identifying that a modified stringing method was being used.

What has been done as a result

The helicopter operator has advised the ATSB that they have made the following changes to their operations manual. The changes relate specifically to the supervision and review of newly authorised pilots in specialist tasks, and includes:

  • Mandated and expanded In Command Under Supervision time requirements for pilots as part of initial task training for relevant specialist tasks.
  • The introduction of consolidation flight checks at key points for pilots newly authorised in relevant specialist tasks.
  • The mandated extension of time that pilots newly authorised in relevant specialist

tasks are mentored by an experienced pilot.

Safety message

This investigation shows that experience alone will not always prevent a pilot from having an accident. In this case the pilot was a very experienced deputy chief pilot with nearly 6,500 flight hours. The ATSB research publication AR-2012-035 provides some insight as to why experience does not always provide a safeguard:

  • Experience alone can never compensate for high risk activity.
  • Sound decision-making and experience do not necessarily go together.
  • Using pilot experience as mitigation for potential operational risks is inadvisable. If the risks are unacceptable for a qualified and competent pilot, there should be no reason for an experienced pilot to accept them.

The investigation also highlights the value of direct supervision of pilots who have recently been trained in a new task.

Download final report
[Download  PDF: 1.67MB]

The occurrence


Safety analysis


Safety issues and actions

Sources and submissions

Safety Issue

Go to AO-2019-015-SI-01 -

Aeropower post-training supervision

There were no requirements in Aeropower procedures to provide any post-training supervision for powerline operations. What supervision was provided was ineffective in identifying that a modified stringing method was being used by the pilot.

Safety issue details
Issue number: AO-2019-015-SI-01
Status: Closed – Adequately addressed
General details
Date: 20 March 2019   Investigation status: Completed  
Time: 10:18 CDT   Investigation level: Systemic - click for an explanation of investigation levels  
Location   (show map): Pernatty Station, 60 km east of Woomera Airfield (Carrapateena Mine)   Investigation phase: Final report: Dissemination  
State: South Australia   Occurrence type: Collision with terrain  
Release date: 09 March 2021   Occurrence category: Accident  
Report status: Final   Highest injury level: Fatal  

Aircraft details

Aircraft details
Aircraft manufacturer Airbus Helicopters  
Aircraft model AS350 B3  
Aircraft registration VH-SZS  
Serial number 7421  
Operator Aeropower Pty Ltd  
Type of operation Aerial Work  
Sector Helicopter  
Damage to aircraft Substantial  
Departure point Carrapateena Airport, South Australia  
Destination Carrapateena Airport, South Australia  
Last update 09 March 2021