At about 300 feet on climb after take-off, the engine suffered a partial loss of power. The pilot turned the aircraft back towards the strip and shortly after aligning it for landing, the engine suffered a further loss of power. The pilot was unable to avoid power lines on the approach path and the aircraft collided with the wires before coming to rest near a house. The engine was still running when the aircraft struck the ground, and the reason for the decrease in performance could not be established.

The pilot was conducting his first solo flight in the aircraft type following a short dual check. During his return to Moorabbin he noted what he considered to be a radio failure. He was concerned because of approaching last light, and made a no-radio entry return to the aerodrome. He made two circuits during which he attempted to extend the gear and flaps using their normal, electrically powered, systems. Although unable to obtain a gear down indication and because he was of the opinion that the problem was related solely to the radios, he elected to land the aircraft without considering the use of the emergency gear extension system. The aircraft subsequently touched down with both gear and flap retracted. Investigation revealed that the aircraft battery was discharged. The pilot had not turned on the alternator field switch during the pre-start or pre-taxy checks. He was surprised to learn of the existence of the field switch when it was mentioned during the subsequent interview.

After landing, the pilot was taxying the aircraft along a marked taxyway between two hangars. Several aircraft were parked in the vicinity, and the pilot taxied at a slightly higher level than normal in order to reduce the effects of downwash. He suddenly noted cables just above eye level, and banked steeply to the left in an effort to avoid a collision. However, the main rotor blades struck and severed the cables, which were a pair of disused Telecom lines strung between the hangars, and both blades then struck the ground. The cables were not marked, and at the point where they crossed the taxyway they were 6.6 metres above the ground.

The pilot brought the helicopter to a hover at 1000 feet agl, pointing approximately into wind. The aircraft began to yaw to the right and the pilot was unable to stop the resulting rotation. The helicopter descended in a steep nose down attitude and struck the ground heavily while still rotating to the right. The landing skids were torn off and the helicopter came to rest on its left side. No mechanical fault or defect was found with the helicopter which might have contributed to the development of the accident. It was considered likely that the aircraft experienced the phenomenon known as "tail rotor breakaway", which results in an uncommanded yaw to the right accompanied by a steep nosedown pitch change. The pilot was aware of the phenomenon, and had read various articles on the subject. However, much of the information available at the time was of a confusing and conflicting nature, and the recovery action employed by the pilot on this occasion was ineffective.

Before he commenced spraying operations in the particular paddock, the pilot had been reminded of the presence of power lines in the area. There was also a group of trees in the paddock, and the pilot sprayed the clear area first, passing over the power lines on at least two occasions. He then advised the property owner by radio that he would spray in the vicinity of the trees "freehand", before resuming normal spraying runs. On the first pass near the trees, the aircraft struck the power lines. The cockpit to fin cable deflector failed and one power line struck the fin about 50 centimetres from the top. The resulting loads caused the rear fuselage to fail, and the entire empennage separated from the aircraft, which dived to the ground and came to rest inverted. The pilot was able to recall that he had the power lines in sight as he lowered the nose to pass under them. It was likely that he misjudged the height of the tail of the aircraft relative to the cockpit with the aircraft in a descending attitude. The injuries suffered by the pilot were made more severe by virtue of the fact that he was not wearing a helmet, and because the seat belt buckle had failed. It was determined that the seat belts fitted to the aircraft were not of a type approved for agricultural operations, but it was not established when or why these particular belts had been installed.

During a flying training sortie the instructor simulated an engine failure by moving the mixture control to the idle cut off position. The student closed the throttle and pulled the carburettor heat on, the instructor then moved the mixture control to rich. During the descent the throttle was opened twice. Prior to commencing a go-around, at about 100 feet above ground level, the student moved the carburettor heat control to cold. At about 200 feet, on climb, the instructor simulated another engine failure by again moving the mixture control to idle cut off. As soon as the student lowered the nose of the aircraft the instructor moved the mixture control to rich, with the throttle open. However, there was no response from the engine and the aircraft was subsequently landed in swampy terrain. No mechanical engine defect was found and tests carried out revealed that the engine should have been capable of operating normally. Atmospheric conditions at the time of the accident were conducive to moderate carburettor icing at cruise power and severe icing at descent power. The carburettor heat control was not operated in accordance with the manufacturer's instructions.

The pilot stated that the strip used for landing was aligned into the morning sun. On late final approach he noticed several kangaroos near the threshold of the strip and decided to land beyond the animals. He reported that just as the aircraft was about to touchdown he saw a small kangaroo and then heard a thump. An inspection of the aircraft revealed that the animal had been struck by the left tailplane. This accident was not the subject of an on-site investigation.

The deceased had been one of a group of four persons undertaking a one day parachute training course. None had any prior parachuting experience. They received about five hours of ground training in normal and emergency procedures, including the correct body position to adopt for a static-line deployment of the parachute. This method of deployment was to be used on their first descent. Each person then successfully completed both a written and an oral examinations of those procedures. The four students then boarded the aircraft along with their instructor and an experienced parachutist, who was to make a video recording of each jump. After takeoff the aircraft climbed to 2500 feet above the drop zone and the first two students completed safe exits and descents. The deceased was expected to jump as the aircraft made a third pass over the drop zone but did not do so and another circuit was made to allow her more time to prepare herself. On leaving the aircraft she was observed to be hunched forward with her arms and legs outstretched, instead of the correct position with the stomach and pelvis pushed forward and the arms and legs spread. She rapidly assumed a stable position on her back, facing upwards, with her body bent and her arms and legs raised. The pilot chute was observed to inflate and pass over her right shoulder until it began to flutter near her head. The main parachute opening sequence failed to continue beyond this point, and the deceased appeared to make no attempt to change her body posture, deploy her reserve parachute or interfere with her parachute equipment before she struck the ground. An examination of the equipment used by the deceased indicated that both the main and reserve parachutes were capable of normal operation. It is considered that the main parachute failed to deploy because of the incorrect body position adopted by the student after she left the aircraft. The reason she then failed to follow emergency procedures was not determined.

Just after take-off, at about 30 feet above ground level, a loud bang was heard and the helicopter started rotating rapidly. The pilot manoeuvred the helicopter clear of fuel drums but it landed heavily while moving rearward. Initial inspection of the helicopter revealed that the tail rotor drive forward short shaft had become disconnected after the failure of the top left longeron. The longeron had failed as a result of high cycle, low stress fatigue. The failure had been developing for some time and should have been noted by maintenance personnel. The decision to take-off over fuel drums restricted the pilot's choices of suitable landing areas and complicated the emergency landing attempt.

On the night prior to the accident heavy rain had fallen in the area. The pilot stated that he carried out an inspection of the centre section of the strip prior to DEPARTURE and found it to be suitable. This inspection did not include the last 150 metres of the strip, in the proposed direction of take-off. The area used for the take-off roll was to one side of the centre of the strip, where the grass cover varied substantially in length and density. Standing water along the strip inhibited acceleration with the result that the nosewheel was not raised off the ground. The aircraft entered large patches of water about 150 metres before the end of the strip, causing the airspeed to decay from 65 to 40 knots. The pilot elected to continue the take-off and the aircraft overran the strip. It then sank into thick vegetation below the strip.