Aviation safety investigations & reports

Engine failure involving Garlick Helicopters UH-1H, VH-ONZ, Ben Boyd Reservoir, New South Wales, on 9 January 2020

Investigation number:
AO-2020-003
Status: Active
Investigation in progress

Update 2

Update published: 30 October 2020

The occurrence

On 9 January 2020, the pilot of a Garlick Helicopters UH-1H was conducting aerial fire control operations when the helicopter lost power and collided with water near Eden (Ben Boyd Reservoir), New South Wales. The helicopter rolled inverted in the water and the pilot egressed from the helicopter. The pilot had recently completed helicopter underwater escape training (HUET). The pilot received minor injuries and the helicopter was substantially damaged.

The helicopter was subsequently recovered from the reservoir and inspected by the operator’s maintenance organisation. A borescope inspection of the engine compressor section revealed a rotor blade failure in addition to other rotor blade and inlet guide vane damage (Figure 1).

Figure 1: Borescope image of damage to engine compressor section

Figure 1: Borescope image of damage to engine compressor section. 
Source: Fleet Helicopters, annotated by the ATSB

Source: Fleet Helicopters, annotated by the ATSB

Engine teardown

An engine teardown was conducted by the manufacturer on 13 and 14 October 2020 at their facility in the United States. In addition to the failed compressor rotor blade, they found blade-tip rubbing of all the axial compressor rotor blades and the centrifugal compressor as a result of contact with their respective shrouds. The forward compressor shaft bevel gear was unevenly worn and exhibited excessive heat. There was a failure of the no. 21 roller bearing, which supported the front of the power turbine shaft, and a failure of the no. 1 ball bearing, which supported the front of the rotating compressor assembly. Both bearing failures exhibited excessive heat and wear, such that they could no longer maintain the centreline of their respective rotating assemblies.

Further investigation

The engine manufacturer has submitted the failed components to their failure analysis group for a detailed metallurgical examination. In addition, they will flow test the bearing support assembly that was used to supply lubrication oil to the no. 21 bearing.

The ATSB will continue to liaise with the operator, their maintenance organisation, the engine manufacturer and the United States National Transportation Safety Board (NTSB).

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The information contained in this update is released in accordance with section 25 of the Transport Safety Investigation Act 2003 and is derived from the initial investigation of the occurrence. Readers are cautioned that new evidence will become available as the investigation progresses that will enhance the ATSB's understanding of the accident as outlined in this update. As such, no analysis or findings are included.

Update 1

Update published: 3 April 2020

The occurrence

On 9 January 2020, the pilot of a Garlick Helicopters UH-1H was conducting aerial fire control operations when the helicopter lost power and collided with water near Eden (Ben Boyd Reservoir), New South Wales. The helicopter rolled inverted in the water and the pilot egressed from the helicopter. The pilot had recently completed helicopter underwater escape training (HUET). The pilot received minor injuries and the helicopter was substantially damaged.

The helicopter was subsequently recovered from the reservoir and inspected by the operator’s maintenance organisation. A borescope inspection of the engine compressor section revealed a rotor blade failure in addition to other rotor blade and inlet guide vane damage (Figure 1).

Figure 1: Borescope image of damage to engine compressor section

Figure 1: Borescope image of damage to engine compressor section.
Source: Fleet Helicopters, annotated by the ATSB

Source: Fleet Helicopters, annotated by the ATSB

Further investigation

The ATSB have interviewed the pilot and liaised with the operator, their maintenance organisation, the engine manufacturer and the United States National Transportation Safety Board (NTSB).

The engine is scheduled to be examined by the manufacturer in the United States under the supervision of the NTSB.

 

_____________

The information contained in this update is released in accordance with section 25 of the Transport Safety Investigation Act 2003 and is derived from the initial investigation of the occurrence. Readers are cautioned that new evidence will become available as the investigation progresses that will enhance the ATSB's understanding of the accident as outlined in this update. As such, no analysis or findings are included.

Initial summary

The ATSB is investigating the collision with water involving a Garlick Helicopters UH-1H helicopter, registered VH-ONZ, near Eden, New South Wales, on 9 January 2020.

While conducting aerial fire control operations, the helicopter was reported to have lost power and collided with water (Ben Boyd reservoir) resulting in substantial damage. The pilot received minor injuries.

As part of the investigation the ATSB will interview the pilot and review other available data.

A report will be released at the end of the investigation. Should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify relevant stakeholders so appropriate and timely safety action can be taken.

General details
Date: 09 January 2020   Investigation status: Active  
Time: 1620 EDT   Investigation level: Short - click for an explanation of investigation levels  
Location   (show map): Ben Boyd Reservoir, Boydtown (near Eden)   Investigation phase: Examination and analysis  
State: New South Wales   Occurrence type: Engine failure or malfunction  
Release date: 30 October 2020   Occurrence category: Accident  
Report status: Pending   Highest injury level: Minor  
Anticipated completion: 2nd Quarter 2021    

Aircraft details

Aircraft details
Aircraft manufacturer Garlick Helicopters Inc  
Aircraft model UH-1H  
Aircraft registration VH-ONZ  
Serial number 5229  
Operator Fleet Helicopters  
Type of operation Aerial Work  
Sector Helicopter  
Damage to aircraft Substantial  
Departure point Merimbula, New South Wales  
Destination Moruya, New South Wales  
Last update 02 November 2020