In the pre-take-off briefing the instructor advised the student that during the flight they would conduct an inspection of the power lines crossing the Herbert River. The student subsequently flew the aircraft, in accordance with the instructor's directions, at about 100 feet above the river. The instructor was aware of four power line crossings. After passing the first, and when en-route to the second, the pilots heard a scraping sound and the aircraft slowed. Despite the attempts of the pilots the aircraft nosed down and subsequently struck the surface of the water at a shallow angle. Investigation revealed that the aircraft had collided with a power line, the presence of which was unknown to the instructor and had not been seen by either pilot. One of the supporting poles was obscured by trees, while the other pole was located approximately 350 metres across the river in a sugar cane plantations. All the wires were estimated to be 100 feet above water level.

Circumstances:

The pilot had previously undertaken a dual instructional flight during which he received instruction in, and practised, approaches simulating a jammed tail rotor pedal control. The pilot was then authorised for a solo flight which was to include practice of "jammed pedal" approaches. During one such approach, the skids contacted the ground while the helicopter was not in straight, balanced flight. The helicopter rolled onto its side in an uncontrolled dynamic rollover. Following the accident, the flying school amended its operations manual to preclude solo students practising "jammed pedal" approaches and landings.

Significant Factors:

The following factors were considered relevant to the development of the accident:

1. The student pilot misjudged the height of the skids above the ground.

2. The helicopter was not in straight, balanced flight.

After touchdown, the pilot applied gentle braking but believed the aircraft was not decelerating. To avoid running off the end of the strip he attempted a ground loop, however, the aircraft ran off the side of the strip and struck a derelict vehicle. An inspection of the aircraft did not reveal any pre-existing defect that could have contributed to the occurrence. It is probable that the pilot misjudged the speed of the aircraft and the distance to the end of the strip when applying the brakes during the landing roll. He was not wearing the sash component of the seat belt and received facial injuries when he struck the control column during the collision with the vehicle.

Circumstances:

During the final approach over a station dam, the helicopter lost height suddenly in a strong down draft. The right skid hooked under a power line which resulted in the loss of control of the helicopter which crashed upside down at the water's edge. A strong South-Westerly wind pattern was established over the area. The approach path was downwind from a stand of large trees.

Circumstances:

The aircraft was being flown for the purpose of endorsing the pilot-under-training. The upper Airwork had been completed and a flapless approach and touch and go landing was to be the final circuit sequence. On the downwind leg the instructor pilot called out the pre-landing checklist, which was apparently complied with by the pilot-under training. At about this time the pilot-under-training was also involved with obtaining an onwards airways clearance through Flight Service. The aircraft was flared normally but settled onto the runway with the landing gear retracted. The landing gear selector was found to have been in the up position. The pilot-in-command said the landing gear warning horn was not heard prior to touchdown.

Circumstances:

Shortly after touching down on runway 22, the aircraft was affected by a localised whirlwind. Despite corrective action, the pilot was unable to prevent the aircraft from entering a ground loop. The left mainwheel ran off the sealed surface causing the aircraft to yaw sharply, resulting in substantial damage to the tail section.

Just prior to lift-off from the private airstrip the pilot stated that the engine misfired. He elected to abandon the take-off and veered the aircraft to the left to avoid a stand of trees just beyond the upwind end of the strip. The aircraft could not be stopped before colliding with the side boundary fence. Investigation revealed that the probable cause of the engine misfiring was lead fouling of one or more of the spark plugs.

Circumstances:

The pilot reported that on arrival in the Beverley Springs area he had some problems contacting Flight Service on the high frequency radio. During this period, he planned to land on runway 34. However, he noticed there was no wind and that the aircraft was positioned to make a short circuit for runway 16 so he decided to land on this runway. Due to the problems with the radio and the sudden change of circuit direction, the pilot forgot to complete the down-wind checks and the aircraft landed wheels up. No gear warning horn was heard, but this may have been due to the higher-than-normal power setting maintained on finals.

As he approached the Macpherson Range the pilot was forced to fly around some hills in order to stay below the cloud base. After crossing a ridge line where the gap beneath the cloud was about 300 feet, the pilot was confronted by a higher ridge. He subsequently advised that the aircraft could not out-climb the terrain and he carried out a controlled entry into the jungle canopy about 200 feet below the top of the ridge. Both wings were torn off however the cabin area came to rest intact.

The pilot had planned to land at a strip on a property 19 kilometres west of the town, however due to the unknown condition of the surface of the strip, he elected to land at the township strip. On the following day, the pilot inspected the strip using a vehicle to test the surface. Due to a soft wet surface at the northern end, 110 metres of the strip was not available. The pilot assessed the remainder of the strip to be firm enough for his planned operation. The pilot flew the aircraft to the strip and during the landing roll, towards the northern end, the nosewheel dug into the surface and the aircraft overturned. There was evidence of sudden heavy braking during the landing roll, immediately prior to the nosewheel digging into the strip surface. It is considered that the sudden application of heavy braking may have caused the nose of the aircraft to pitch down. The nosewheel broke through the surface of the strip and soft damp soil compacted to stop the nosewheel rotation causing the nosewheel to dig in further and the aircraft to overturn. This accident was not the subject of an on scene investigation.