The flight was the first session of the Private Pilot's constant speed unit and retractable landing gear training. The aircraft was taking off on Runway 11 Centre for the training area. The pilots reported that at a height of about 50 feet, the engine failed completely, surged briefly, then failed completely again. The instructor took over control and landed the aircraft. The aircraft overran the runway, passed over the top of a 4 to 5 metre deep drainage ditch, and impacted heavily on the top of the far bank, approximately 190 metres from the end of the bitumen runway. Lost movement was found between the fuel selector pointer and the fuel selector valve, and with the selector pointer positioned by sight the valve may have been in such a position as to restrict fuel flow at high power settings. The accident highlighted the airmanship which should be exercised when making a fuel selection, by feeling for a detent and not simply relying on the position of a pointer. Although such a defect would normally be discovered and rectified during regular servicing, lost motion may develop from a stiff selector valve, eventually resulting in disagreement between a position indicator and valve position.

The pilot had been carrying out crop spraying operations, and was hurrying to return to his base before last light. He was concerned with the fuel state, and made an enroute landing, where one of the passengers dipped the tank. Believing that adequate fuel remained, the pilot took off again, but shortly afterwards the engine lost all power. During the subsequent autorotation, manoeuvring was necessary to avoid power lines. The helicopter then landed heavily and the main rotor blades struck and severed the tail boom. It was determined that at the time of the accident the aircraft had been operating for 7 minutes longer than the expected total endurance. The pilot had not kept an accurate record of fuel usage, and it was likely that his decision making processes had been impaired by fatigue. It was probable that the helicopter had been resting on sloping ground at the time the tank contents were checked, resulting in an erroneous reading on the dipstick.

The pilot had landed the helicopter in a clearing in order to refuel from drums carried in the aircraft. During the subsequent take-off into the strong wind prevailing, downdraft was experienced as the aircraft approached a heavily timbered area. A turn was carried out to avoid the trees but the combined effects of the downdraft and the downwind turn resulted in the helicopter touching down heavily. The impact forced the landing skids rearwards, bending the associated vertical support members.

Towards the end of a spraying run the pilot noticed that the aircraft was drifting towards a power line running roughly parallel to the aircraft track. He attempted to counter the drift but the aircraft moved underneath the wire. The main rotor struck the line as the pilot attempted to manoeuvre clear and also avoid trees at the end of the spraying run. After striking the wire the helicopter swung through 180 degrees and the tail boom collided with a tree. Although the pilot had gained considerable experience on helicopters, most of this had been obtained cattle mustering. He evidently did not realise that a hazardous situation was developing in time to take safe avoiding action.

Circumstances:

At 2000 feet, during a navigation exercise, the instructor initiated a practice forced landing. When the instructor was satisfied with the student's performance, the student initiated a go-around at about 200 feet above the ground. At about the same time the front of the helicopter contacted a powerline. The helicopter pitched up severely and lost speed rapidly. The single wire snapped after damaging the main rotor mast cover and bending control rods to the main rotor. The instructor took over and immediately carried out an autorotative landing. The wire had a span of approximately 600 metres between two hills. It was difficult to see. This accident was not the subject of an on-scene investigation.

Circumstances:

During a landing attempt, the pilot lost directional control of the aircraft. The aircraft entered foliage at the side of the strip.

Initial touchdown occurred about one third of the way along the 518 metre strip. A slight bounce followed and as soon as the aircraft had settled on the ground again the brakes were applied. There was no noticeable retardation and the pilot attempted to go around. The nosewheel struck a gable marker just prior to the boundary fence, and the left mainwheel contacted the top strands of the fence. The fuselage was punctured by a fence post and the pilot abandoned the take-off attempt. An inspection of the strip immediately after the occurrence revealed a very heavy dew on the short, thick grass surface.

While cruising at 150 feet agl and 40 knots the engine failed. During the subsequent attempted autorotational landing the pilot tried to turn the helicopter into wind but a heavy landing resulted while the helicopter was still drifting to the right. The landing skid attachments collapsed and the main rotor and tail rotor struck the ground as the helicopter bounced and tilted to the right. The engine failed due to fuel exhaustion. A wasp nest had blocked the fuel vent line and the fuel gauge was reading in error because the fuel cell had partially collapsed.

The pilot, with his wife as passenger, was conducting a bore inspection. A search was instigated when the helicopter did not return by night fall. The wreckage was found the next morning. The helicopter had struck the ground in an inverted attitude amongst trees in a dry swamp. There were no witnesses to the accident. The subsequent investigation concluded that control of the helicopter had been lost at a low height and the helicopter had crashed inverted while the rotor was under positive 'g' flight loads, with little rolling motion. No evidence of pre-accident failure of the helicopter or occupant incapacitation was found. Examination of the wreckage and the surrounding area indicated that the helicopter had struck a tree, by settling into its crown, prior to control being lost. No reason for the descent into the tree could be established. It is probable that, following the tree strike the pilot over-reacted with the collective control and was then unable to regain control of the helicopter in the height available.

The aircraft had recently been returned to service after a landing accident which involved a failure of the right maingear. The pilot had only flown the aircraft once since the accident and was conducting circuit training to restore his currency. On his second circuit, the landing was heavier than normal and on the right side of the grass strip. During the landing roll, the pilot heard an unusual noise and the right wing dropped slightly. Despite efforts by the pilot, the aircraft veered off the right side of the strip into soft plowed ground and came to rest on the right wingtip. Examination of a broken rear bracing tube of the right maingear showed that it had failed in overload. There was no evidence of a pre-existing fault, however, the possibility that the failed component had been weakened in the previous accident could not be discounted.