The helicopter was engaged in the mustering of feral pigs for a cull. After descending the helicopter to follow the pigs into a cleared area, the pilot noticed that more power was required to fly the aircraft. The aircraft was immediately returned to base and landed, where an inspection revealed damage to the leading edge of both rotor blades. The damage was consistent with the blades striking small branches of trees. The pilot reported that neither he nor his passenger had been aware of the helicopter striking any objects.

The aircraft had not been flown and had stood in the open for about two months. Some 20 minutes after DEPARTURE the engine commenced to run roughly, and the pilot elected to divert to the nearest suitable aerodrome. Shortly afterwards, the engine backfired severely and black smoke entered the cabin through an air vent. The engine subsequently stopped completely and the pilot was committed to a forced landing on unsuitable terrain. The gear collapsed and the aircraft collided with two fences before coming to rest. On vacating the aircraft, the pilot discovered that a fire was burning under the cowls on the right side of the engine. The fire was extinguished by the pilot and passengers. The cause of the engine failure could not be determined. However, the insulation of both magneto coils was badly deteriorated. It is considered likely that during the period that the aircraft was inactive, moisture accumulated in the magnetoes. This moisture, together with the deteriorated insulation, probably caused the magneto to misfire and fail. The fire developed in the engine bay after severe backfiring caused the exhaust cluster on the right hand side of the engine to separate from the muffler. The hot exhaust gases then ignited the fibreglass cowling and the melting resin emitted the black smoke which entered the cabin via the hot air vent.

Following a dual check, the pilot was authorised to carry out three solo circuits and landings. The first of these was completed satisfactorily, but on the next landing the aircraft bounced and the pilot applied full power in order to go around. Shortly afterwards the aircraft sank, struck the ground with the nosewheel and the left wing, and overturned. The pilot later advised that he had held the control column fully back during the go-around attempt, and he had not raised the flaps from the fully lowered position.

As the aircraft was being flared for the landing, a mob of sheep ran onto the strip. Two sheep were hit by the aircraft, one being thrown up against the left flap and the other struck the right tailplane. The landing was completed without further incident. The strip was not fenced off from the rest of the paddock and the pilot did not see the mob as he approached to land.

The aircraft was returning to land at the completion of a local flight. The pilot, who had only recently purchased the aircraft, had not flown it before with four persons on board. He was compensating for a crosswind, and misjudged the flare, probably because of the higher sink rate of the heavier aircraft. The aircraft touched down and bounced several times, before ground looping and coming to rest at the edge of the flight strip.

In the course of a daily inspection, a LAME discovered that the aircraft had sustained damage to the nosewheel support structure and the firewall. It was evident that the damage had occurred as a result of a heavy landing. The last pilot to fly the aircraft reported that after landing at Albany he had noted that the nosewheel oleo was flat. After seeking advice from the aircraft operator, he had flown the aircraft back to Jandakot. It was possible that the damage had occurred during the landing at Albany. The pilot had limited experience on type and the aircraft was operated near its maximum gross weight. The pilot stated that he was high on the approach at Albany so he rapidly closed the throttle prior to hold-off. The nose attitude was high and although the mainwheels contacted the runway first, when the nosewheel touched-down, it did so harder than normal.

The planned exhibition jump into the football stadium was delayed due to a gusting 30 knot(54 kilometres per hour) wind. After about 30 minutes a report was received that the wind strength had abated. A decision was then taken to proceed with the jump. When the aircraft arrived overhead the stadium the jump ground controller advised the pilot, by radio, that the wind strength was eight knots(15 kilometres per hour) and the four parachutists exitted the aircraft. The first three parachutists landed safely within the playing field. It was reported that the parachute of the fourth parachutist collapsed at an altitude of about 180 feet during a sharp right turn. The parachute spun to the right descending rapidly until the parachutist struck the facia of the north-east stand. Several witnesses reported that the wind strength was in excess of 8 knots, and as a result it is likely that conditions above the stadium would have been turbulent. Medical reports indicate that at the time of the accident it is likely that the parachutist's judgement was impaired by the effects of alcohol. Tests carried out on the parachute found that it would collapse during radical manoeuvring in turbulence, however, control could be quickly regained when the correct technique was applied. It is considered that on this occasion the parachutists handling of the jump was consistent with his judgement being impaired by the effects of alcohol.

The pilot reported that while the aircraft was established in cruise, the engine RPM suddenly increased and the windscreen covered with oil. The engine oil pressure gauge was indicating zero. During the subsequent landing, the aircraft ran off the sealed roadway. An inspection of the aircraft revealed that the constant speed unit oil transfer line had failed due to fatigue. This resulted in the engine oil being pumped overboard.

A student parachutist was exiting the aircraft for a static line jump, when a portion of the main canopy became entangled around the right horizontal stabiliser. Approximately half the right elevator was torn away, together with a portion of the trim tab, while the outer section of the stabiliser was bent downwards through 45 degrees. The parachutist landed safely, and the jump instructor then made a normal descent. The pilot was able to retain control of the aircraft, and elected to divert to a more suitable aerodrome, where an uneventful landing was subsequently carried out. The parachutists were using a static line bag deployment system. This system does not require a pilot parachute to extract the main canopy from its container, but the airspeed and attitude of the aircraft are critical to ensure safe operations. On this occasion, it was probable that the airspeed was higher than desirable at the time the parachutist exited the aircraft. However, the parachute school had not provided specific operating instructions for pilots engaged in this particular form of parachute dropping. In addition, it was considered that the static line attachment point was in a less than optimum position inside the aircraft, in that it reduced the available vertical distance between the attachment and the tailplane. It was also possible that the parachute may have been incorrectly packed, leading to earlier than normal deployment.

Circumstances:

The pilot, who had limited experience on the Bell 47, attempted to bring the aircraft to a quick stop at approximately 50 feet above ground level. During the manoeuvre, the cyclic control reached its forward stop. The pilot lowered the collective control in an attempt to recover the situation however his inexperience caused him to lose full control of the aircraft. The tail rotor struck the ground before the pilot was able to regain control. The subsequent landing was heavier than normal.