On downwind after the first take-off following a scheduled servicing the pilots were unable to fully extend the landing gear. After all efforts to lower the gear by normal and emergency methods were unsuccessful, the pilot in command carried out a safe landing with the gear retracted. Part of the work carried out during the servicing included the replacement of 'O'-ring seals in the main gear up-lock valve. During re-assembly of this valve, a ball bearing, whose function was to direct fluid to the actuator, was omitted. When the system was activated, insufficient pressure could be generated to fully extend and lock the gear.

The pilot reported that just after lift off the engine seemed to lose power. She manoeuvred the helicopter to a suitable landing area, but during the landing the main rotor blades struck a sapling. The helicopter was then repositioned to another landing site where the engine was shutdown and the damage to the main rotors noticed. An inspection of the engine revealed that the number two and four exhaust valves had been sticking and that the valve guides were out of tolerance. It is probable that the loss of engine power was a result of the exhaust valves sticking.

At the conclusion of a parachute dropping sortie, the pilot landed the aircraft at the strip in a strong crosswind. During the landing roll the aircraft began to swing to the left and the right gear leg collapsed. The right wing, tailplane and elevator were bent after contacting the ground. The aircraft was one of four operating from the strip, when the wind backed and increased in strength, during the passage of a weak front. The pilot had been aware of the change in wind velocity before attempting the landing.

The pilot stated that just after the aircraft became airborne it encountered a strong gust of wind. The left wing tip and nosewheel struck the ground and the aircraft overturned. During the take-off run the pilot held back pressure on the control column and at 50 knots selected 10 degrees of flap, the aircraft becoming airborne after a ground roll of only 170 metres. The take-off distance required was 650 metres, however, the take-off was attempted on an unprepared salt pan with an available take-off distance of 300 metres. The pilot had operated from this area previously but on this occasion the aircraft was at a higher all up weight. The wind gust reported by the pilot was probably associated with a willy willy, encountered when the aircraft was at a low airspeed.

Circumstances:

The helicopter collided with powerlines whilst engaged on a pig spotting flight.

As part of a communications propagation test, personnel were to be positioned in the Oraparinna National Park by helicopter. One person was being lowered by winch when, at about 3 metres below the helicopter and 4 metres above the ground, his harness became detached from the winch hook and he fell to the ground. The reason for the harness becoming detached from the winch hook could not be determined.

After returning from the local training area, the pilot joined the circuit for a landing. He stated that he flared high, added some power whilst allowing the aircraft to descend, then reduced power again. The aircraft contacted the runway heavily in a slightly nose down attitude. The firewall, lower fuselage skin and control tunnel were all deformed, causing control difficulties during the subsequent taxying. Following the high flare the pilot failed to adequately arrest the sink-rate. Skid marks on the runway in the vicinity of the touchdown, and a substantial single bald patch on the right tyre indicated that the right brake was probably applied at touchdown.

The pilot had just washed the helicopter, and carried out a circuit to dry the machine. At the completion of the circuit he intended to carry out a practice autorotation. The pilot reported that after turning onto final he noticed that the wind direction had altered so he decided to extend the final leg and selected a different touchdown point. As he flared the aircraft he noticed that the ground sloped and decided to apply some collective and touchdown on a flatter surface. The aircraft touched gently but the pilot reports that the main rotor RPM had decayed and a violent resonance occurred. The subsequent inspection of the tailboom found that the skin had been rippled near the forward end.

The pilot approached for a landing into the east. The wind was from the south east and gusting from 10 knots to 30 knots. On short finals, half a kilometre before the threshold, the aircraft encountered a strong windshear. The pilot applied full power but the aircraft was still unable to outclimb a low ridgeline ahead. At a very low height the pilot applied full back stick in an attempt to slow the aircraft before touching down in low scrub. Just before ground contact the left wing-tip struck a small tree and the aircraft slewed to the left. The nosewheel broke off as it struck the ground and the aircraft came to rest about 400 metres short of the strip. The pilot had been unaware of the extent of the very gusty conditions which produced the windshear. There was no wind direction indicator at the strip, which might have alerted the pilot to the actual conditions.

The pilot decided to make an unscheduled landing at an aerodrome enroute to check a problem with the aircraft. On touchdown he noticed steel pickets on either side of the runway and reapplied power. During the go-around the left wing tip struck a picket, the aircraft yawed and then collided with other pickets, before the aircraft was brought to a stop. The aerodrome had been closed for reconstruction work. White crosses were placed on the runway and adjacent to the windsock. The pilot had not advised Flight Service of his intended landing. The aircraft nose attitude on approach reduces forward visibility and the pilot did not see the white crosses on the runway. The aircraft yawed as power was applied for the overshoot.