Collision with terrain

The pilot reported that it was the first time he had flown the type of glider, and it had been over 3 years since he had flown a glider with water ballast. Prior to the flight he had forgotten to drain the water, and he had departed with the ballast tank about half full.

As he made his approach to land, during an out-landing, the water shifted causing one wind to drop suddenly. The wing tip hit the top of a fence, yawing the aircraft to the right. The landing gear was torn off on touchdown and the left-wing tip then dug in causing the aircraft to ground loop to the left.

The pilot reported that on arrival over the landing area he noted there was a south-easterly wind of about 30 knots. He therefore planned to land into the south-east. He conducted a low pass in the planned landing direction at about 50 ft above the ground and observed there was no turbulence. He then made an approach at 80 knots with 20 deg of flap selected. At approximately 40 to 50 ft above the ground the aircraft encountered a high rate of sink Despite the application of full power and backstick the aircraft hit the ground heavily, dislodging the nose gear. It then slid for about 25 metres before turning over and coming to rest inverted.

The pilot said there was a hill to the south of the landing area, and he was aware this hill could cause turbulence when there was a southerly wind blowing. However, on this occasion he encountered very strong shear which he now believes is unpredictable in that he did not encounter it when he made the low pass prior to his landing approach.

The aircraft was taking off from an agricultural strip for a rice sowing flight, carrying 1,000 kg of rice seed. The aircraft became airborne momentarily before settling back onto the strip. The pilot was unable to stop the aircraft before it collided with a low fence and a contour bank.

There were active thunderstorms reported in the area at the time, and it is likely that the aircraft encountered adverse windshear during lift-off.

The aircraft was engaged in spraying operations over a crop of rock melons. The pilot had not previously sprayed crops at this farm. During one of the spray runs the right wing struck a thin metal pole located at the edge of the paddock. The pilot was able to maintain control of the aircraft and diverted to land safely at a nearby air strip.

The farmer who normally removed the steel pole had forgotten to remove it on this occasion or to notify the pilot of its location.

The 5 to 6 m high pole was constructed of 25 mm square steel tubing. The pilot later said that he saw the obstacle too late to avoid a collision.

The pilot was involved in spraying operations, and this was his first take-off for the day. The strip was 700 m long, covered with 30 cm long grass and ran downhill to the east. There was no wind at ground level, so take-off was to the east. After liftoff, at an altitude of about 10 ft, the pilot experienced tail buffet and then sink. The aircraft then hit a fence and gate at the end of the strip which tore off a spray boom, tailwheel and main wheel. The pilot dumped the load and landed straight ahead.

After the accident the pilot and the company chief pilot made a closer assessment of the strip and surrounding terrain. That assessment indicated that the point from where the take-off run was commenced was probably shielded from a light westerly breeze (i.e. a tailwind) but once the aircraft got airborne closer to the eastern end of the strip, the westerly breeze was encountered. Although the strip was covered in long grass, it was evident from wheel marks that the aircraft had become airborne after a ground roll of between 450 and 500 m.

The aircraft was engaged in aerial spraying operations. The weather at the time of the accident was reported as fine, with clear skies and calm wind conditions. Toward the end of a swathe run, involving a descent into a small valley followed by a climb over rising terrain, the pilot was required to manoeuvre the aircraft over a powerline.

The pilot reported that, as the aircraft approached the powerline, the engine experienced a partial loss of power and did not respond when full power was applied. He elected to fly beneath the powerline, in order to avoid it, but considered this action may have been taken too late as he was unable to arrest the aircraft's rate of descent in time to negotiate the rising terrain on the far side of the powerline. The contents of the hopper remained on board the aircraft during the accident sequence as the pilot did not have an opportunity to jettison the load. The aircraft impacted heavily onto rocky ground about 50 m beyond the powerline and was substantially damaged. The pilot escaped without injury.

As the Bureau did not conduct an on-site examination of this occurrence, the reason for the apparent loss of power could not be determined.

The pilot was tasked with spraying crop with fungicide in a paddock situated in an undulating timbered area. The wind was from the east at 10 - 15 kt, and the pilot elected to commence the first spray run in a downwind direction. This required a steep descent from over the treetops to pass beneath a swer power line located across his flight path.

The pilot reported that he encountered severe turbulence and windshear in the lee of the trees, and was unable to prevent the aircraft, which had a full hopper, from descending into the top of a tree. This caused an immediate deterioration in airspeed, damage to the wing leading edges and removal of the spray pump. The aircraft flew out of the tree in a semi-stalled condition, and being unable to maintain height to fly over the swer power line the pilot dived the aircraft to pass beneath it.

The aircraft wheels became entangled in the crop, slowing the aircraft further, and caused it to impact the ground heavily. The impact damaged the landing gear and removed the hopper door allowing the fungicide load to dump.

Due to the impact force, and the load being dumped, the aircraft became airborne again and was yawed to the right by the crop dragging on the landing gear. It then collided with a fence which turned it through 180 degrees as it came to a stop.

The aircraft was engaged in aerial seeding and was being operated from a grass strip. The pilot reported the take-off direction was towards the north-west, to take advantage of a 12-15 kt wind blowing from slightly left of the take-off direction. The aircraft became airborne with about 100 m of the strip remaining but failed to accelerate and climb out of ground effect. Turbulence was encountered about 100 m beyond the end of the strip, which yawed the aircraft to the right, through about 60 degrees.

The pilot selected the hopper dump lever to the fully open position, in order to jettison the load, and attempted to manoeuvre the aircraft to avoid a line of trees. When it became apparent, he would not be able to fly over the trees, he tracked towards the clearest area within the tree line. At a height of about ten feet the wings collided with small trees. The aircraft continued for a short distance before striking the ground and sliding to a halt. The pilot escaped without injury. He was subsequently told, by a person who had been located nearby, there had been a major wind gust/shift in the area at the time of the accident.

After carrying out a damage inspection of the aircraft, the pilot reported that about 90% of the load had remained in the hopper during the accident sequence. Whilst he described the load of seed and superphosphate as dry and free flowing, he considered that the design of the hopper base was not satisfactory, as the gate-like opening inhibited the free flow of solids. Had he been able to jettison a greater portion of the hopper load in the time available, he believed the resulting improved climb performance of the aircraft would have allowed him to avoid the trees.

The hopper base was described as a gate box type, principally designed for use with liquids. The pilot indicated that operators may use this style of hopper base for both liquid and solid applications during those times when the aircraft may be required to frequently change from one medium to the other.

The aim of the flight was to check the front seat pilot's capabilities in assessing and flying slope-lift generated by mountain slopes. The area near the mountain became unsuitable for continued operations due to mist and the presence of other aircraft. As a result, the crew decide to return to their base. The instructor reported that as the glider passed through a saddle, with sufficient height and speed to reach the airfield, it was caught in a series of downdrafts. A significant amount of altitude was lost in the turbulence and the glider continued to lose altitude rapidly once it reached clear air. The air brakes were found in the fully deployed position. They had not been selected by either pilot. The glider was 300 ft above ground level and over trees when the air brakes were selected in. The glider had insufficient performance available to reach the airfield.

The pilots decided to complete an outlanding on a road. The space between the trees on either side of the road was less than the glider's wingspan and the right wing and canopy collided with trees during the landing. The glider came to a stop in the trees at the side of the road.

It is probable the airbrakes were deployed by the loadings encountered during the turbulence.

The Piper Pawnee was spraying chemical in the local area. The strip being used was 350 m in length, and had several trees at the far end, some 16 m to the left of the departure path. There was a crosswind from the right of about 10 to 12 knots. The strip surface was soft, but the pilot reported he had not experienced any problems during a previous take-off, although the aircraft was unladen.

Prior to the next take-off the aircraft was loaded with chemical. The pilot subsequently reported that late in the take-off run, with the engine operating normally, the aircraft suddenly slowed and slewed left about 20 degrees, before again accelerating normally. The aircraft lifted off at approximately 65 knots, displaced to the left and further along the strip than on the previous take-off. The pilot reported he was unable to prevent the aircraft colliding with the trees located to the left of the normal departure path. This resulted in the aircraft rolling inverted and striking the ground. It is considered the left mainwheel may have struck a soft area of the strip during the take-off run, causing the initial left yaw and slight deceleration.