Collision with terrain

The pilot was spraying crops adjacent to the Leigh River. The river meanders through a steep sided valley oriented approximately north-south, with the crop being sprayed located above the west ridge of the valley. The pilot advised that he had refuelled the aircraft and refilled the hopper.

The wind was gusting from the south-west and he was on a spray run, tracking to the south, at 5 ft above the ground, when a gust of wind caused the left wing to drop. The pilot advised that he was unable to stop the wing hitting an embankment and the aircraft rolled into the valley, coming to rest upright, substantially damaged and burning.

The pilot suffered a broken ankle and burns but was able to extricate himself. The aircraft was destroyed.

The helicopter was being flown in support of geological drilling operations and had just been used to externally sling-load a pump into a creek bed. The refuelling point and landing area were located about 20 m from the edge of a ravine which was approximately 30 m deep and 100 m wide. A tree was growing from a point below the top of the ravine and the tree's tops protruded approximately 3 m above the ravine's edge. When the pilot flew the helicopter to the landing area to refuel, he lowered the external sling to the ground and then flew the helicopter backwards approximately 1 m, intending to land next to the fuel drums.

As the pilot was landing the helicopter, evidence indicates that the left skid became caught on a rock. When the pilot attempted to fly the helicopter clear, the left skid suddenly broke clear of the rock. The helicopter rolled right as it climbed, and the right skid impacted a pump housing protruding from the top of a fuel drum before striking the top of the tree located on the ravine's edge.

The helicopter continued drifting and began yawing right as it descended into the ravine. The pilot reported that just as he was regaining some control of the helicopter, it landed, upright, on a rock shelf approximately 2 m from the ravine floor. It appears that at this stage, the main rotor impacted the helicopter's tail boom. The helicopter then rolled and fell off the rock shelf to the ravine floor. It came to rest on its right side with the engine still running and main rotor turning.

The pilot reported that he then closed the throttle, turned the fuel switch off and exited the helicopter through the front windscreen, having suffered minor injuries. He also reported that he turned off the emergency locator transmitter beacon although it did not appear to be operating.

During the landing, evidence indicates that the left skid became stuck in the rock. When the pilot attempted to reject the landing, it is likely that he would have used a combination of up collective and right cyclic as the helicopter pivoted around the left skid. It appears that the rock then broke. The sudden release of the left skid, associated with the cyclic and collective control positions probably caused the helicopter to rapidly roll and drift right. As the helicopter climbed, rolled and drifted, it was likely that the pilot could not have quickly regained control due to the subsequent impacts with the fuel pump and tree. It was probably fortunate that the helicopter entered the ravine, giving the pilot time to recover some control before the landing on the rock ledge. The forces and imbalance generated by the main rotor strike on the tail may have then caused the helicopter to rollover, fall off the shelf before finally coming to rest on the ravine floor.

The pilot was conducting a charter flight from Moorabbin to French Island and return. He was carrying 3 passengers with light luggage. On arrival at French Island, he landed to the east on the grass strip. While taxying after landing the nose wheel became bogged in sandy soil near the eastern end of the airstrip. The pilot shut down the engine and the passengers helped him push the aircraft to a parking position facing west at the eastern end of the strip. This location enabled the pilot to use the full length of the grass strip for a take-off to the west later in the day. Later, when the group returned to depart the outside air temperature was approximately 14 degrees Celsius, the wind was calm and the QNH was approximately 1021 mb.

The airstrip surface was slashed grass and much of the soil underlying the grass surface was sandy loam. In the take-off direction the strip was slightly up hill until about midway, and then slightly downhill. The airfield was approximately 131 ft above sea level and the surrounding terrain was gently undulating. The pilot applied full power and held the aircraft on the brakes before commencing the take-off roll. The passengers reported that the aircraft accelerated normally for about 100 metres, after which the rate of acceleration slowed. As the aircraft neared the western end of the strip and the pilot rotated the aircraft to become airborne the passengers advised that they heard a noise which they believed was caused by the tail of the aircraft striking the ground. The pilot did not recall a noise as the aircraft rotated but said that he noticed a slight change in engine note soon after liftoff.

The aircraft climbed to about 20 ft, banked slightly left and then settled back onto the ground approximately 70 m from the point of lift-off. It skidded down a gentle slope through light foliage and logs, slewed to the left and came to rest about 135 metres beyond the end of the strip. As the aircraft stopped, the pilot and passengers saw flames in the cabin. The pilot's door had jammed shut because of fuselage damage, therefore all occupants evacuated quickly through the right door. Within seconds the aircraft was engulfed in flames. None of the passengers reported hearing the stall warning horn at any stage. They reported that the engine sounded as though it was producing take-off power even after they heard the tail hit the ground. Although the aircraft was substantially damaged by fire no pre-existing fault was found with the aircraft.

Because of the fire damage, the stall warning system could not be tested. The maintenance release was issued for operation in the aerial work category which did not embrace the requirements for this charter flight. The pilot reported that he had selected 1/4 flap for the take-off. The flaps were found in the up position after the accident; the flap selector may have been knocked up during the impact. The pilot estimated that the take-off weight was 1006 kg, which included 36 litres of AVGAS. Subsequent calculations showed that the take-off weight was 1017 kg, which was 49 kg below the maximum allowable weight. The pilot reported that he had checked the aircraft performance data before the flight and assessed that a 600-metre strip would be adequate for taking off over a 50 ft obstacle in nil wind conditions. None of the performance charts included factors for degradation of aircraft performance due to wear and tear, or for the slowing affects of sandy loam underlying a grass surface.

The operator reported that prior to conducting charter operations on French Island, two company pilots had measured the strip using vehicle odometers and recorded a length of 600 metres in the company's authorised landing area register. Using a calibrated wheel after the accident, the strip was re-measured and found to be only 500 metres long.

The pilot stated that he was mustering bulls approximately 5 km west-north-west of Kalmeta homestead. He said he was approximately 40-50 ft high when he hit a wire. He did not see the wire prior to impact. The pilot said that when he realised he had hit a wire he took all necessary action, but lost control of the helicopter, and it fell backwards to the ground. The pilot said that due to the impact and injuries he sustained he did not remember anything further.

The pilot was conducting his first commercial agricultural spraying operation and had been operating on the task for several hours in the afternoon. He was asked by the farmer who owned the property being sprayed, to avoid spraying in the dam on the paddock. Whilst the pilot was attempting to identify the dam, the aircraft's left wing clipped the top of a tree, and the aircraft descended steeply into the ground. The pilot was able to escape from the wreckage, having sustain soft tissue damage, fractures to lower vertebra and both ankles dislocated.

The owner reported that the tail rotor of the helicopter came into contact with a small tree as the pilot was pushing some cattle into a yard. The helicopter then spun out of control to the ground, landing heavily on the left skid before rolling over. The pilot was able exit the helicopter without injury. The owner advised the helicopter was damaged beyond economical repair.

Post flight examination showed that one of the tail rotor blades had separated in flight when it came into contact with the tree.

The pilot reported his aircraft had been hangared since April 1994. He had become seriously ill in November 1994 but, in the past 12 months, he had made a good recovery. He decided that he would go with a friend, who was a qualified pilot, to pick up his aircraft from Roma where it was hangared. The aircraft was flown from Roma to his friend's property.

On the afternoon of the accident, the pilot was using a 220 m runway for take-off, but this distance was well within the performance capability of the aircraft. The friction nut for the throttle control in the aircraft was not functioning correctly, and it was possible for the throttle control to slide back from the full throttle position by about 2.5cm, if the throttle was not held in position manually.

The pilot stated that after becoming airborne in about 70 m he went to apply full flap after building up some speed to clear some low trees at the end of the runway. He said that as he let go of the throttle to apply extra flap, the throttle control slid back with a corresponding reduction in engine power. By the time he realised what had happened and reapplied full throttle, it was evident that the aircraft would not clear trees at the end of the strip. He said he was then left with no alternative but to pull the nose up and 'belly' the aircraft through the trees.

The pilot of the helicopter was conducting a familiarisation flight for the wife of the station owner who had contracted the helicopter. It was late afternoon, with the sun low on the horizon and the fine weather with no cloud or wind. End of daylight was approximately 1745. The homestead, from which the helicopter departed, was located to the west of a swamp. The swamp's water depth was approximately 1 m and the surface was reported as being mirror-flat at the time of the accident. There were two islands located in the swamp and their foliage had a maximum height of approximately 3 m.

The helicopter departed at approximately 1700 and tracked north, climbing to approximately 800 ft AGL before completing a counterclockwise circuit towards the swamp. The pilot decided to make a shallow, northerly approach to the southern island. The island's southern shore was approximately 500 m from the mainland approaching from the south. As the helicopter crossed the mainland-shore on the final approach, the pilot assessed his height as being 20 to 30 ft. 

Late in the approach the pilot decided that a landing on the island was impractical and he commenced a go-around. He stated that he placed the helicopter in an accelerative-attitude and commenced a slight right turn to avoid a bird. The passenger, sitting in the right seat, stated that she thought that the helicopter was at about 10 ft from the surface of the water as the turn commenced. She recalled a spray of water from the front right side just before the helicopter impacted the water. 

The occupants remained secured to their seats and the helicopter remained substantially intact although the canopy bubble imploded, the tail rotor gearbox was flung clear and the main rotor system and fuselage were substantially deformed. The wreckage spread and passenger report indicate that it is likely that the main rotor struck the surface of the water causing the helicopter to cartwheel before coming to rest upright.

After the impact, the occupants released themselves from the wreckage and waded ashore. They reached the shore at approximately 1725.

The pilot later reported that he was unaware of the difficulties associated with visually judging height over calm water. Lacking a radio altimeter, the final approach starting altitude and shallow angle was inappropriate in the prevailing conditions. It is likely that, when the pilot selected the accelerative-attitude and commenced the right turn, the helicopter descended slightly causing the main rotor to strike the surface of the water. The smooth water surface, failing light and low foliage height probably caused the pilot to underestimate the helicopter's height above the water and not perceive a slight descent during the go-around.

The floatplane took-off from a coastal lake in strong gusting winds associated with passing squalls. As the aircraft approached the coast, and flew over the beach at low altitude, it descended until the left float struck the top of a wave. The aircraft nosed over into the ocean and began to sink. The pilot and passenger managed to evacuate the semi submerged aircraft without injury.

The pilot subsequently reported that, after taking off toward the south into the strong wind, he had to turn left at low altitude to avoid a small hill adjacent to the shore. The aircraft had then probably encountered windshear on the downwind side of the hill, which resulted in the unintended loss of altitude and subsequent contact with the water.

The aircraft was involved in a cotton spraying operation. The pilot reported that on the tenth take-off the aircraft failed to accelerate to normal climb speed, only reaching a height of about 15 ft. He dumped the load but was unable to prevent the aircraft descending into the cotton crop. Although the aircraft was substantially damaged the pilot was uninjured.

The engine subsequently performed normally during a test run. The pilot reported that he remembered strong 'willy willy' activity in the area immediately after the accident. He concluded it was likely that the take-off performance of the aircraft had been adversely affected by a wind gust at liftoff.