The pilot conducted the pre-take-off checks, including the engine runup, while taxiing for take-off. This resulted in a higher than normal taxy speed. Anticipating a 180 degree turn to align the aircraft for take-off, the pilot moved the aircraft to the right of the strip and looked back over his left shoulder. The right wing struck a four metre high tree which was located 10.5 metres to the right of the strip centreline. The aircraft pitched forward, lurched to the left and the left wing struck the ground before the aircraft settled back onto its gear. The pilot had suffered a delayed DEPARTURE earlier in the day due to the requirements of his business. He had not operated into the strip previously and did not notice the tree during an aerial inspection prior to landing.

The helicopter was being used as an platform for test equipment. Part of the test equipment included an aerial that was mounted vertically below the helicopter. This aerial could be retracted and stowed in a horizontal position for landing by operating a control which was positioned in front of the technician. On this occasion the pilot inadvertently attempted to land the helicopter with the aerial extended. Just prior to touch down the helicopter began to vibrate, the pilot lowered the collective and the helicopter rolled onto its right side. Following the completion of each test it was normal for the technician to raise the aerial prior to landing. On this occasion, the technician became engrossed with the transmission of test data and forgot to retract the aerial. The pilot was concentrating on the landing and neglected to ensure that the aerial had been retracted. Normally if a landing is attempted with the aerial extended a weak link in the system fails and the aerial is retracted by a spring. However, it is believed that because the helicopter touched down with little forward speed the weak link did not fail at the required time in the landing sequence.

The pilot landed the aircraft on a nine metre wide gravel road to check on one of his staff, working nearby. Following the check, the pilot commenced a takeoff towards the west in 10-15 knot northerly wind. At an indicated airspeed of about 40 knots the aircraft drifted to left off the side of the road. The pilot continued with the takeoff attempt but the aircraft continued to turn to the left, downwind, and travelled about 600 metres before the nosewheel entered a ditch and the aircraft overturned. During the takeoff attempt into-wind aileron was not used to conteract the crosswind. The takeoff attempt was not discontinued when the aircraft diverged from the intended takeoff path.

The pilot was engaged in mustering operations and was attempting transition from a low forward speed to an out of ground effect hover in order to turn a breakway beast. As he approached the hover, the helicopter experienced a sudden partial power failure. The pilot maintained the aircraft heading, lowered the collective lever and attempted to gain some forward airspeed. In the attempted landing with partial power, the helicopter struck the ground heavily and its main rotor blades hit a small sapling. The forced landing was made in light downwind conditions. Investigation revealed that the No 2 cylinder exhaust valve had failed in fatigue and the valve seat and retaining cap had failed in overload. Further testing indicated that the exhaust valve had been subjected to higher than normal operating temperatures which would have contributed to the premature failure of the valve.

The pilot was attempting to take off from an eight metre wide road. He initially aligned the aircraft so that it was pointing to the left of the intended takeoff path, to avoid a tree just off the side of the road. Just after full power was applied, as the pilot was realigning the aircraft after passing the tree, the left maingear overran a windrow on the edge of the road and the aircraft ran off the road. It mounted a one metre high dirt mound and rolled inverted.

After landing, as the pilot lowered the collective lever, the helicopter entered ground resonance. Recovery action was not taken by the pilot and one of the main rotor blades struck a fuel drum. The resulting imbalance of the main rotor system caused the rotor mast to separate from its attachment. An inspection of the helicopter revealed that the undercarriage oleo struts had incorrect and differing inflation levels, and that the main rotor dampers had been incorrectly assembled.

After flying for about an hour the pilot noticed that the engine was running roughly. A magneto check was carried out and a dead cut detected on the left magneto. The pilot decided to land the aircraft on a nearby claypan but misjudged the approach and attempted a go-around. The engine failed to deliver full power and the aircraft struck trees before coming to a halt. The spark plugs were found to be heavily fouled with lead, carbon and oil deposits. Following the cleaning of the plugs a significant rpm drop was no longer present when the magnetos were tested. However, the required minimum static engine rpm could not be obtained and subsequent inspection of the engine revealed it to be in generally poor mechanical condition.

The pilot reported that the engine stopped without warning during cruise at 3000 feet. Restart attempts during an autorotation were unsuccessful. The helicopter was landed in a small clearing and the tail boom was severed. The investigation revealed particles of contaminant in the fuel control unit and the strainer drain system. However, it is not conclusive that this contaminant was the cause of the engine failure. No other defect was found which may have contributed to the engine failure.

The pilot stated that the last refuel used super motor fuel, taken from the station bulk storage and decanted into an empty 200 litre aviation fuel drum, before being pumped into the aircraft. The refuelling of the aircraft had taken place two days before the accident. Following the refuelling, the pilot had taken a fuel sample but believed it to be free of water. No additional fuel samples had been taken prior to the accident. An inspection of the aircraft fuel system revealed a substantial quantity of water present in the carburettor bowl, fuel strainer bowl and both wing drain points. There is little doubt that this quantity of water was sufficient to cause the engine to fail.

The aircraft was being flown at about 900 feet above ground level while the pilot spotted horses for a programmed muster. When the pilot attempted to increase engine power, he found that there was no response to throttle movement. Pumping the throttle resulted in a decrease in power to idle. The pilot was unable to correct the situation and selected the best available area for landing. This area was covered with small basalt boulders. On touchdown the left wing struck a small dead tree and the propeller struck the ground before the aircraft came to rest. It took the pilot some time to exit the cabin of the aircraft because the doors had been jammed during impact. An inspection of the aircraft revealed that the outer throttle cable had come loose from the clamp at the carburettor. This allowed power to be reduced but not increased.