Aviation safety investigations & reports

Collision with terrain involving a Robinson R22, VH-RBO, near Daly Waters (ALA), NT on 28 June 2015

Investigation number:
Status: Completed
Investigation completed

Final Report

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On 28 June 2015, at about 1500 Central Standard Time (CST), a Robinson R22 helicopter, registered VH-RBO, took off from a property near Daly Waters, Northern Territory, for a local flight including inspection of bores on the property. The temperature was about 30 °C with a south-easterly wind at 10-15 kt. After flying for about 20 minutes, the pilot, who was the sole occupant of the helicopter, landed to open a gate. The pilot selected the governor off, then exited the helicopter, leaving the engine running. The pilot then re-boarded the helicopter and took off.

After a further 5 to 10 minutes of flight, when at about 100 ft above ground level, and an airspeed of 40 kt, the pilot conducted a turn to the south. The low rotor revolutions per minute (RPM) warning horn sounded. The pilot immediately wound the throttle fully open, and lowered the collective to try to regain rotor RPM. The helicopter continued to descend. The pilot attempted to flare the helicopter when low to the ground. The main rotor blades collided with tree branches. The helicopter landed heavily, the skids dug in to the soil and the helicopter rolled onto its side.

The pilot sustained minor injuries and the helicopter sustained substantial damage.

The Robinson Helicopter Company Safety Notice SN-24 states that rotor stall due to low RPM causes a very high percentage of helicopter accidents. These mostly occur close to the ground during take-off and landing. Safety Notice SN-10 reminds pilots to have their ‘reflexes conditioned so they will instantly add throttle and lower collective to maintain RPM in an emergency’.


Aviation Short Investigations Bulletin - Issue 43

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General details
Date: 28 June 2015   Investigation status: Completed  
Time: 1600 CST   Investigation level: Short - click for an explanation of investigation levels  
Location   (show map): near Daly Waters (ALA)    
State: Northern Territory   Occurrence type: Collision with terrain  
Release date: 07 October 2015   Occurrence category: Accident  
Report status: Final   Highest injury level: Minor  

Aircraft details

Aircraft details
Aircraft manufacturer Robinson Helicopter Co  
Aircraft model R22 Beta  
Aircraft registration VH-RBO  
Serial number 0810  
Type of operation Aerial Work  
Sector Helicopter  
Damage to aircraft Substantial  
Last update 14 November 2018