On the morning of the accident a periodic inspection had been completed on the aircraft. Following this inspection, the pilot, accompanied by an engineer, carried out a satisfactory test flight in the helicopter. The pilot then lunched with the engineers and after farewelling them at the airport was driven to the helicopter to prepare for the flight back to the mustering camp. The helicopter was later observed by a stockman who was travelling in a vehicle towards the mustering camp. When the helicopter was first seen it was flying at a height of about 200 feet above the tops of the trees in the direction of the camp. It then appeared to stop, turn abruptly through 90 degrees to the left, roll to the left and spin through 360 degrees before impacting the ground inverted. At about the same time as the helicopter turned to the left an object was seen to fly horizontally away from the aircraft to the right. After ground impact a fire broke out and engulfed the wreckage. An extensive search of the area failed to locate the object that had fallen from the helicopter. However it is believed that the object may have been one of several cans of oil or grease the pilot was known to have carried in the aircraft. The examination of wreckage did not reveal any defect in the helicopter which was likely to have contributed to the occurrence. The reason for the loss of control by the pilot could not be determined.

The aircraft had been parked in the open overnight. When the pilot arrived at the strip he noted that shallow fog had settled over the area. The temperature was below freezing point and frost covered the aircraft, except for the windscreen which had been protected by a cloth sheet. A pre-flight inspection was carried out, but did not include the removal of the frost from the aircraft. Because the fog had reduced visibility to about 50 metres, the pilot taxied the aircraft along the strip to check for obstructions. During this time the moisture froze on the windscreen, however by reaching from the cockpit the pilot was able to clear the left side of the screen. Shortly afterwards the take-off was commenced and the lightly loaded aircraft became airborne after a ground run of about 250 metres. At this point all forward visibility was lost because of frost re-forming on the windscreen. The pilot noticed that the aircraft appeared to be banking to the left and he elected to land immediately. The left wingtip contacted the ground, followed by the main wheels. The aircraft ran off the side of the strip and collided with a fence, before coming to rest about 100 metres from the strip. The pilot had had no disciplined instrument flying experience and had been unable to maintain effective control of the aircraft during the take-off with severely restricted visibility. The degradation in aircraft performance as a result of the frost covering the wings and tail surfaces could not be established.

Prior to the first flight on the day the pilot inspected the fuel tanks of the aircraft and estimated they contained 225 litres of fuel. On that basis he planned a flight of 155 minutes duration. Approaching the second last turning point of the flight the engine stopped. The pilot selected the other fuel tank, power was restored and a diversion made to the nearest suitable airfield. On final approach to that airfield the engine stopped again. The aircraft was landed heavily in a paddock and the nose gear leg torn off. The aircraft had been parked on sloping ground which could account for the over-estimation of fuel contents. As the flight was conducted at 3000 feet, no attempt was made to lean the mixture although fuel consumption was increased 24 percent by running the engine at full rich mixture. Suitable forced landing areas were overflown enroute to the diversion aerodrome because the pilot thought that the fuel gauge was in error. The aircraft stalled during an attempt to prolong the glide to a more suitable area.

The pilot reported that as the aircraft was climbing through 3000 feet when it suffered a bird strike. The aircraft was landed at the DEPARTURE aerodrome without further incident. The bird, an eagle, became embedded in the vertical stabiliser.

The pilot had planned to carry out a cattle muster in conjunction with another aircraft. He had been late in departing his base but when he found the other aircraft had not yet arrived at the rendezvous point he decided to make a quick comfort stop. The helicopter was landed on a spinifex covered area and the pilot disembarked leaving the engine running. Shortly afterwards he noticed a fire underneath the helicopter and reboarded in an attempt to fly it away from the fire. The engine did not respond. The pilot disembarked and attempted unsuccessfully to extinguish the fire. He received burns to his hands and legs while unloading equipment and the helicopter was destroyed.

The aircraft was cruising at 1500 feet agl when a large bird was struck. Substantial damage was caused to the right wing of the aircraft, however the pilot subsequently carried out an uneventful landing.

Circumstances:

On the day of the accident, the pilot had ferried the helicopter from Scone to Tomalla Station. He conducted an aerial inspection with the station manager before commencement of blackberry spraying activities. The accident occurred during the 14th spray flight whilst the pilot was attempting to fly the helicopter between two large trees. The pilot lost control of the helicopter when the main rotor blades struck branches of one of the trees. The helicopter impacted the ground heavily and soon after the pilot vacated the cabin, a fire started which destroyed the helicopter. The pilot said there was sufficient clearance for the helicopter to pass safely between the trees.

During cruise the pilot noticed that the electrical system was malfunctioning. The ammeter was reading zero, the system was switched off and a diversion for landing carried out. The pilot reported that, on arrival in the circuit area, the landing gear could not be lowered by the emergency system. A wheels-up landing was made. An inspection of the aircraft revealed that the electrical problems were due an alternator failure which resulted from a faulty connection on a brush lead. The reason that the gear was unable to be lowered by the emergency system could not be determined.

The pilot selected a 340 metre long taxiway as the take-off path. After a ground roll of about 250 metres, at an indicated airspeed of approximately 55 knots, the pilot rotated the aircraft and it became airborne, but did not climb away. He then closed the throttle and the aircraft collided with several trees before coming to rest. The pilot was unfamiliar with the airfield but had been advised that the strip was 915 metres long. He was unaware that the take-off path he had selected was along the taxiway which led to the strip. Prior to the attempted take-off, he had been involved in an argument with his employer and was probably also fatigued after a week of extensive business travel.

The pilot had operated into the strip two weeks prior to the accident flight, and saw a powerline that had apparently been diverted underground, near one end. After checking with his passengers who were familiar with the area, a landing was made. On this flight a flatter approach was made and the nose leg snagged on the powerline causing the aircraft to impact the ground in a steep nose down attitude. The 10 metre high powerline had been diverted to cross the approach area, above ground, 274 metres from the threshold.