Aviation safety investigations & reports

Engine power loss and forced landing involving Robinson R22 Beta, VH-HCX 4 km south west of Geraldton Airport, Western Australia on 20 February 2021

Investigation number:
AO-2021-008
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final

Download Final Report
[Download  PDF: 736KB]
 

What happened

On the morning of 20 February 2021, a Robinson R22 Beta helicopter, registered VH-HCX, was being repositioned from a storage depot near Geraldton Airport to Murchison House Station near Kalbarri, Western Australia. Shortly after lifting off, at about 30–40 ft above the ground, the engine’s performance reduced and the helicopter began to descend. The pilot completed a forced running landing in a yard adjacent to the point of departure. The pilot then elected to reposition the helicopter. However, on becoming airborne, the helicopter began to rotate nose‑right. In response the pilot landed the helicopter.

What the ATSB found

The ATSB found that an inlet valve in the engine’s number-four cylinder sustained thermal damage, which led to reduced engine performance and required the pilot to conduct a forced landing. The loss of directional control during the subsequent lift-off resulted from a loss of drive to the tail rotor due to the tail rotor drive shaft fracturing in torsional overstress close to its connection with the tail rotor gearbox.

Safety message

This occurrence serves as a reminder for pilots of piston engine helicopters, like the R22, to be alert for unexpected yawing and transient reduced engine performance during flight. These characteristics may be symptomatic of developing engine intake valve damage. If this condition remains unattended it can lead to an increased risk of induction backfire events, and significant loss of engine power.

Additionally, when a loss of engine power or abnormal operation is encountered, an appropriately licensed maintenance engineer should complete an engine cylinder inspection in accordance with the helicopter and engine manufacturer’s most recent service instructions before further flight. Maintenance organisations should note that when completing a differential compression test of the engine cylinders, an accompanying borescope inspection of the cylinders and valves will provide an effective method to visually assess the condition of these components.

Download Final Report
[Download  PDF: 736KB]
 
 
 

The investigation

SUMMARY

The Australian Transport Safety Bureau (ATSB) has commenced a transport safety investigation into the tail rotor malfunction of a  Robinson R22 Beta, registration VH-HCX, near Geraldton in Western Australia. 

On 20 February 2021, the helicopter was being operated by a sole pilot for an early morning repositioning flight from a station property near Geraldton to Kalbarri, Western Australia. Shortly after departure, the helicopter’s engine commenced a period of ‘rough running’, and with that onset the pilot elected to conduct a precautionary run-on landing in a yard adjacent the departure helipad. The intermittent period of engine operation reportedly eased, after which, the pilot proceeded to lift the helicopter into a low hover. During this the pilot encountered a loss of antitorque from the tail rotor system leading to an uncommanded rotation of the helicopter. The pilot immediately resettled the helicopter and on landing shutdown the engine. The pilot’s post-flight inspection of the helicopter identified that the tail rotor drive shaft had fractured.

As part of the investigation, the ATSB will review review and analyse any available recorded data, interview involved parties and gather any other relevant information.  

A report will be published at the conclusion of the investigation. However, should any critical safety issues be identified at any stage during the course of the investigation, the ATSB will immediately notify relevant parties so appropriate safety action can be taken.

General details
Date: 20 February 2021   Investigation status: Completed  
Time: 0830 WST   Investigation level: Short - click for an explanation of investigation levels  
Location   (show map): 4 km south west of Geraldton Airport   Investigation phase: Final report: Dissemination  
State: Western Australia    
Release date: 16 December 2021   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Robinson Helicopter Co  
Aircraft model R22 Beta  
Aircraft registration VH-HCX  
Serial number 1582  
Operator Fortescue Helicopters  
Type of operation Aerial Work  
Sector Helicopter  
Damage to aircraft Minor  
Departure point near Geraldton Airport, Western Australia  
Destination near Kalbarri, Western Australia  
Last update 16 December 2021