While wheel taxying for take-off minor ground resonance occurred. The pilot lifted the helicopter off the ground and the resonance ceased. Severe main rotor vibration started and the pilot landed the helicopter. Ground resonance then began with one main rotor blade striking the cabin roof and severing the tailboom. The helicopter then turned through 180 degrees as it sustained further damage. Inflight main rotor imbalance was caused by the failure of a blade damper. The failure resulted from the seat displacement of a one-way valve by a portion of perforated plate. Blade imbalance then induced the failure of a main rotor spacer cable. Loss of control necessitated a landing and severe ground resonance induced by blade imbalance resulted.

The pilot was conducting a flight to pick up a VIP passenger from a strip at which he had not previously landed. After an aerial inspection he approached with gear down and flap half extended. The aircraft struck the end of the strip heavily causing deformation of the forward pressure bulkhead, twisting of the right wing and bending the right maingear and right propeller blades. Although the pilot stated that he intended to go-around at 50 feet, analysis of propeller impact marks in the strip surface indicate that the aircraft struck the ground at a low power setting before go-around power was applied. The aircraft became airborne again after a ground roll of 112 metres and the pilot diverted to Parafield where a landing was carried out without further incident. A subsequent survey showed that the strip did not meet minimum ALA requirements in respect of length, width, slope or approach gradients.

Circumstances:

The pilot had completed one sortie of about one and a half hours consisting of upper air work and circuits. He had occupied the right seat, which is the normal pilot seat. As he was training for an Instructor Certificate, he later commenced a second sortie flying from the left seat, having previously been checked out for flying from both seats. Circuits were to be conducted with landings into a wind of 8 to 10 knots. The pilot reported that for the first landing the aircraft was lifted by a wind gust, and a heavy touchdown ensued. The aircraft bounced and he applied a small amount of power, but on the second touchdown, the left landing gear collapsed, and the aircraft tilted onto its nose. The pilot reported that he attributed the accident to slight confusion at the time of the initial bounce, due to reversal of hand position, for the different seats.

The pilot had been advised of a displaced threshold, and assessed that the available length was adequate. The displaced threshold was forgotten until the markers were sighted during final approach. Power was applied to land beyond them but the aircraft was allowed to balloon and float before touching down, and overran the end of the strip where the landing gear collided with a low windrow. The pilot inspected the landing gear for damage, and believing the aircraft was airworthy, continued with the flight schedule. Subsequent examination revealed that the airframe had suffered substantial damage. This accident was not the subject of an on scene investigation.

Shortly after takeoff on a scenic flight, the passenger commenced taking photographs. In the process, his goggles became partly dislodged and began striking the rear cockpit. The pilot reached forward to rectify the situation and, as he replaced his hand on the throttle control, the engine failed. Because of the low altitude of the aircraft, the pilot was forced to land in a rough boggy area within the airfield boundary. The aircraft struck a large depression and nosed over shortly after touchdown. The pilot reported that he had inadvertently knocked the rear ignition switches to the off position, probably with his jacket sleeve, as he reached forward to help his passenger adjust the dislodged goggles.

Circumstances:

It was the pilot's normal practice to commence descent to the circuit area at a point 10 kilometres from the strip. On this occasion the descent was initiated 4 kilometres from the strip, and the aircraft was some distance past the strip when the pilot was ready to conduct the downwind checks. During the checks he elected to leave the landing gear up until the final approach checks. Had the landing gear been extended at the normal point in the check sequence, the pilot expected that he would have to apply extra engine power which he did not wish to do. Shortly after starting the final checks, he was distracted by a radio call from another aircraft. He responded to the call and then restarted the final checks, but in the wrong order. The aircraft landed with the flaps fully down and the landing gear retracted. The pilot reported that he did not hear the warning horn.

At the end of an uneventful flight from Morven the sole passenger disembarked and watched while the pilot restarted the engine and commenced to taxy. The passenger next observed the aircraft when it was about 30 ft above the ground after take-off. At this time the aircraft was steeply banked to the left and shortly after it passed from sight the engine noise ceased and the sound of trees breaking was heard. The wreckage of the aircraft was subsequently located at the threshold of another of the aerodrome strips. It was determined that the aircraft had collided with trees while it was in a left wing down attitude before rolling inverted and striking the ground. The precise cause of the accident could not be determined, however the possibility that the right wing flap was jammed in the fully down position after the previous landing could not be discounted.

On the pull-up at the end of the first spray run in that particular direction, the aircraft struck a single wire power line. The pilot immediately landed the aircraft in a clear area. During the landing roll the right wheel struck a large rock, which was concealed in long grass, and the right maingear was torn off. The aircraft pitched forward onto the engine and came to rest in a near vertical attitude. Before he commenced treatment of the area, the pilot surveyed it from the air and questioned the owner on the whereabouts of any obstructions. However, he did not check the area from the ground. Although he had been told of the presence of the wire, it was further from the paddock and higher above the ground than he had expected. The span between poles on the section of wire struck by the aircraft was 540 metres.

The pilot was a member of a group of Chinese ex-military pilots who were being trained to allow them to reach the equivalent of an Australian Agricultural rating. He had almost completed this course and was being checked on a simulated spraying exercise by an Examiner of Airmen watching from the ground. The pilot, who did not speak English, was being provided with instructions via an interpreter. At the completion of the check, the pilot intended to carry out a normal landing into the east. However as he was about to turn downwind, he was advised to "come back quickly". A steep turn was made to position the aircraft on a low and close base for landing into the west. The final approach turn was overshot, and during the attempt to line up with the strip the aircraft stalled, struck the ground heavily and overturned. The instructor supervising the training of the pilots had noticed that thunderstorms were developing about 20 kilometres south of the strip. He had asked the interpreter to advise the remaining pilots not to waste time during their respective flights, in case the storms moved closer. The interpreter, who did not have an aeronautical background, had misconstrued the message and had passed the instruction to return quickly to the pilot. During the modified approach the pilot had not monitored the airspeed and had insufficient height available to recover control when the aircraft stalled.

The pilot was approaching to land after a soaring flight of about 90 minutes. When about 300 metres short of the threshold he realised that the aircraft was undershooting and he was conscious of a loss of airspeed. He closed the airbrakes and lowered the nose but said that he got very little response. He then pushed the nose down further to try to regain speed. By this stage he was very close to the airfield boundary. The left wing clipped a fence and the aircraft struck the ground and skidded to a halt. The wind at the time of the accident was reported as a 15 knot northerly with occasional gusts to 20 knots. There was some evidence of wind shear on final approach. The investigation established that two days prior to the accident the pilot carried out a check flight with an instructor in an IS28B glider. Prior to that flight he had only made two sailplane flights in the previous 10 months both being under the supervision of an instructor. Between the check flight and the accident flight the pilot made two local soaring flights each of about 90 minutes duration. Of his 915 hours total flying experience 70 were in gliders. This accident was not the subject of an on-scene investigation and the circumstances described above are based on the pilot's report.