The aircraft crossed the threshold higher than the pilot desired, and touchdown occurred well into the 900 metre strip. After initially running normally along the ground, the aircraft bounced twice before coming to rest in a nosedown attitude. Investigation revealed that the aircraft had landed on the left side of the strip, where the surface was very rough, and the aircraft had suffered a broken nosegear fork. The nosewheel had become detached and the nose strut was pulled away from the firewall. The pilot was feeling fatigued after completing 7 hours flying for the day. He had elected not to go around when the aircraft was high on the approach, as adequate strip length remained for a safe landing. The rough area of the strip was not visible from the air, and the aircraft entered this area at a higher speed than would have resulted from a touchdown at the normal aiming point.

The pilot intended to conduct a series of night circuits and landings to maintain currency. On the second circuit, the gear was selected down but failed to fully extend. All attempts to lower the gear were unsuccessful. The aircraft subsequently touched down with the partially extended gear, which collapsed as the aircraft slid to a halt. An inspection of the aircraft revealed that the failure of left maingear hydraulic actuator resulted in the loss of hydraulic fluid and prevented completion of the gear extension cycle.

The pilot was taking a group of mentally retarded children for a flight. On the first flight one of the children became distressed and the flight was terminated. On final approach for the first landing of the second flight, the child seated behind the pilot became hysterical and grabbed the pilot around the throat. A missed approach was carried out and another circuit completed. As the aircraft approached for landing the child again became agitated. The pilot reported that he was concerned about the situation and lost concentration during the approach. The aircraft ballooned and landed heavily.

Approaching the circuit area the pilot selected the landing gear down, but the appropriate gear position light did not illuminate. The pilot then noticed that all electrical systems were inoperative. He subsequently advised that he checked the mechanically operated position indicator, and was satisfied that the gear was down. Witnesses observed the aircraft making a normal approach but then saw the gear collapse shortly after touchdown. Initial investigation revealed that the aircraft battery was fully discharged. The aircraft alternator had failed some time previously, and the battery had been steadily depleted. However, this situation would not have been evident to the pilot, as the ammeter was defective and showed a steady charge at all times. The last part of the gear extension cycle results in a very small movement of the position indicator, and it is considered difficult to assess the precise position of the gear by reference to the indicator. The aircraft handbook warns that a discharged battery may prevent the gear from fully extending by electrical power. The pilot was aware of this warning, but had not employed the emergency lowering procedure to ensure that the gear was locked down.

At about 200 feet above ground level on final approach the pilot noticed kangaroos near the threshold. He adjusted the approach to fly over the animals but the aircraft subsequently landed heavily about four metres to the right of the centre of the strip. The aircraft slewed to the right and struck a mound of rubble, which was about 50 centimetres high. The right maingear and nosegear folded and the aircraft slid to a halt 105 metres after the point of touchdown. The pilot had landed at the particular strip, which was at an elevation of 4500 feet, on one other occasion. The strip, which did not meet ALA requirements, sloped upwards at 6 degrees over about one third of its length and was 21 metres wide. Mounds of rubble from grading lined each side of the strip, and it was likely that had these not been present, damage to the aircraft may have been avoided. The reason the aircraft landed heavily was not positively determined, but was probably related to the pilot's lack of experience with operations into sloping strips.

Circumstances:

The pilot proposed to conduct a flight around the Station windmills. His attempt to start the aircraft was unsuccessful owing to the battery condition. He turned the ignition, and master switches OFF and proceeded to hand swing the propeller. As he turned the propeller, the engine fired. The throttle had been left half opened, the park brake was not engaged, and the aircraft was not chocked. The aircraft moved rapidly, and the pilot was unable to gain access to the cockpit. The aircraft passed through a fence and subsequently came to rest in a clump of trees. No defect was discovered to explain how the engine could start with the ignition and master switches selected OFF.

Earlier in the day the pilot had flown VH-MDI from a mining camp at Windy North to Broome. On arrival at Broome, at 0913 hours, the pilot was handed a completed flight plan by his Chief Pilot, and briefed for two flights to Koolan Island. The purpose of these flights was to convey nine or ten passengers from Koolan Island to Derby. The aircraft was subsequently refuelled to full tanks and departed Broome at 0956 hours arriving at Koolan Island at 1103 hours. After loading five passengers and their luggage, the pilot taxied the aircraft for take-off from runway 23. Runway 23 is 810 metres in length and has an overall uphill slope of 1.17 percent. The wind at the time was a direct crosswind of between 10 and 15 knots. The aircraft became airborne approximately 54 metres before the end of the runway. It was observed to descend into a small ravine off the end of the runway, then climb steeply and strike power lines before impacting the ground in a near vertical nose down attitude. Following the impact, the aircraft cartwheeled once and burst into flames. Investigation disclosed that the take-off had been commenced from a point approximately 50 metres in from the threshold of the runway. The all-up-weight at the commencement of the take-off exceeded the maximum permitted for the runway selected by about 320 kilograms, given the prevailing conditions. Examination of the wreckage did not reveal any evidence of mechanical defects which could have contributed to the accident. This was the first time the pilot had flown a Cessna 210 type aircraft into Koolan Island although he had been checked on island operations in a different aircraft type by the Chief Pilot.

The pilot was aware that there was an area of soft ground on the strip. The area was marked by a cone marker, which was about 10 metres in from the edge of the strip. The pilot intended to land some 100 metres beyond the cone, however turbulence and strong sink was encountered during the latter stages of the approach. As the aircraft touched down, the tailplane struck the cone marker, which was made of galvanised iron.

The student was receiving instruction in autorotative techniques. The crew completed several autorotative descents terminating in power recoveries. The instructor then demonstrated an autorotation during initial climb at 50 knots, simulating an engine failure after take off. The helicopter was levelled and throttle and collective applied, but the instructor was unable to arrest the rate of descent and the helicopter landed heavily. Following a bounce, the left skid dug into the ground and the helicopter cartwheeled before coming to rest upright, facing in the reciprocal direction to the landing. The instructor commenced the practice autorotation after take off at too low a height/speed configuration. Despite the use of power, he was unable to reduce the excessive sink rate prior to ground impact.

On arrival at his destination, the aircraft overflew the homestead. This was the pilot's normal practice, to indicate to persons on the ground that transport from the nearby strip was required. The aircraft was then seen apparently following a gully containing a sunflower crop in which the pilot and passenger were partners. Shortly afterwards the sounds of an impact were heard. The aircraft was found to have struck the side of the gully while in a steep nosedown attitude and probably rotating to the right. No pre-impact defect or malfunction of the aircraft was found which might have contributed to the development of the accident. However, about 12 months previously, the pilot had applied tape over the stall warning vane, thus depriving him of aural warning of an impending stall. The wreckage distribution was consistent with that which follows a stall at low level where control of the aircraft is not regained before impact. It was likely that the aircraft stalled while the pilot was manoeuvring above the crop, but the precise reason for the stall and subsequent loss of control was not established.