Collision with terrain

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.

It was reported that the flight had initially been planned as a circuit training exercise. When the wind was reported as a 20 kt crosswind the flight was cancelled. As the aircraft taxied back to the parking area the pilots received a report that the crosswind had dropped to 15 kt. They then decided to take-off and complete some upper air work.

Shortly after the aircraft became airborne, with the pilot-under-instruction at the controls, it encountered a strong wind gust which caused it to roll to the right and descend. The instructor took over control of the aircraft and attempted to correct the situation. Although the aircraft apparently started to respond the instructor assessed that his input was not correcting the situation quickly enough and he closed the throttle, held the control column back and allowed the aircraft to descend to ground level.

The aircraft impacted nose first, to the right of the flight strip, before sliding to a stop and overturning.

The Bureau of Meteorology reported that the wind was gusting between 12 and 21 kt and changing direction from 340 to 010 degrees at the time of the take-off. The pilots were using runway 06L.

It was reported that planned mustering and other activities had been significantly delayed by poor weather and there was pressure to complete the task. The pilot did not sleep well on the night prior to the accident because of his concern about progress.

On the day of the accident the station strip was assessed as unsuitable for aircraft operations due to its soft surface. As a last resort, arrangements were made to fly the aircraft from an access road. A straight section of the road, 350 m long, was selected. There was a cattle grid, with guideposts, at the end of the section. The pilot estimated there was sufficient distance available to become safely airborne.

During the take-off the pilot experienced control difficulties caused by vehicle ruts in the road surface. The aircraft veered to the left and the left main wheel entered a soft area. The aircraft's acceleration was retarded but, as there was insufficient room to stop safely, the pilot continued with the take-off. Immediately after lift-off there was a loud bang. The pilot thought the tail wheel had struck one of the guideposts. Although the aircraft appeared to be operating normally, he elected to complete an immediate landing on a serviceable airstrip about a kilometre away. During the landing roll the left main landing gear collapsed as a result of damage caused by the collision with the post.

The student pilot was making an approach for a normal landing. During the landing flare he raised the nose too high, and the aircraft ballooned. The student attempted to correct the situation by adding power and lowering the nose. The aircraft was no longer aligned with the runway and the student used the rudder to turn the aircraft. As he was completing this action the stall warning sounded. The student opened the throttle to full power, to go around, but he did not stop the aircraft from pitching more nose-up nor did he centralise the rudders. The aircraft stalled, pitched nose down and rolled to the left. The left wing and propeller struck the ground before the student could take any further action. The student turned the magneto and power switches off before leaving the wreckage.

The student's inexperience was the major factor in his misjudgement of the approach and his use of incorrect recovery action.