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.

After completing the first swath run the pilot climbed the aircraft over a single set of power lines. At the end of the second run the aircraft was flown under these wires. When the pilot then commenced a climb he observed a second set of wires, he attempted to fly the aircraft under them but the canopy of the aircraft struck the wires. The aircraft remained airborne, however, by using the rear vision mirror, the pilot saw that the fin and rudder were extensively damaged. Rather than risk a loss of control situation he landed the aircraft in a field of tall sugar cane. Prior to commencing the task the pilot was given a map of the area by the property owner. The map was marked with the area to be sprayed and also had indicated, by the use of crosses, a power line at the end of the spray run. The pilot assumed that these crosses indicated only one set of wires. Being anxious to complete the task he did not carry out a reconnaissance before commencing to spray.

The pilot was ferrying the aircraft to a nearby strip because of planned runway works at Newman. After holding overhead the strip, while two other company aircraft landed, the pilot descended the aircraft into the circuit and completed the prelanding checks. He elected not to lower the gear at that time because he considered the airspeed was to high. The aircraft was subsequently landed with the gear retracted. The pilot stated that he was concentrating on to carry out a good landing. Although he recalls touching the landing gear selector on final, he does not recall checking the gear position indicators. This accident was not the subject of an on-site investigation.

The pilot was attempting to takeoff on a wet strip, which sloped markedly down from the centre towards each end. To minimise the effect of a slight tailwind, and to avoid an obstruction at the end of the strip, the pilot planned to angle the ground run. Takeoff was commenced from the left side of the strip, but when the aircraft had reached the top of the hump in the strip, the pilot realised that he had angled the run excessively and was now outside the markers on the right side. The aircraft subsequently collided with scrub and trees. The strip markers were difficult to see, and had compounded the pilot's difficulty in accurately assessing the angle at which he planned to carry out the takeoff. At the point where the pilot realised the aircraft was running off the side of the strip there was insufficient distance remaining to either abandon or safely continue the takeoff attempt.

Following a dual check, the student was briefed to carry out a series of circuits and landings. During the first of these the aircraft microphone failed, and a full stop landing was made in order to obtain a replacement. A normal takeoff and circuit was then flown, however the aircraft was low on approach and the pilot elected to carry out a go-around. After reaching a height of about 200 feet the aircraft was placed in level flight. A descent was then commenced, followed by a turn through 270 degrees. At this point the aircraft touched down in a paddock, became airborne again, then collided with a roadside sign and a power line. It then struck the median strip of a main road and came to rest after colliding with the aerodrome boundary fence. Initial investigation revealed no fault or malfunction of the aircraft which might have contributed to the accident. The student was making his sixth solo flight and had accumulated less than 2 hours in command. No fault was found with the aircraft which might have contributed to the accident. The pilot had experienced considerable learning difficulty during his training as indicated by his having flown only two hours solo in a total of 50 flight hours.

The helicopter was being operated at about 40 feet above ground level at an indicated airspeed of 45 knots, when the engine suddenly failed. During the subsequent landing attempt the main and tail rotors struck trees and the helicopter contacted the ground tail first, severing the tail skid and tail rotor blades. Inspection of the engine revealed that the carburettor air filter screen was blocked by dirt and the alternate air source door had been glued in the shut position.

Prior to DEPARTURE, the pilot had obtained a weather briefing, which indicated that deteriorating conditions were forecast. This forecast proved to be accurate and the pilot was forced to carry out a number of diversions to remain in visual contact with the ground. The fuel state of the aircraft also became critical, and in the face of further deterioration in the weather conditions, the pilot attempted to land on a racecourse. A normal touchdown was made, but the aircraft slid off the banked track and collided with the inside guard rails.