The pilot was conducting a flight to check the output of the spray system fitted to the aircraft. During the take-off he heard a noise from the rear of the aircraft and noticed something moving away from the aircraft. He continued with the take-off and two spray runs before positioning the aircraft on a downwind leg for landing. As the aircraft was turned onto the base leg the pilot realised that he could not apply left rudder. The pilot stated that he then intended landing the aircraft on the base leg but found that cone markers blocked the path. The aircraft was then lined up with and landed on runway 22. An inspection determined that the leaf-spring mounting that retains the tailwheel had failed due to fatigue. The loss of rudder control experienced by the pilot resulted from the bending of the left rudder to tailwheel control arm so that adequate left rudder could not be applied. It is considered that the leaf-spring failure should have been detected during routine maintenance or pre-flight inspection.

At the end of each spray run to the east, the aircraft was flown under a power line before the turn to change direction was commenced. Several runs had been completed when the pilot climbed the aircraft to commence the turn and the aircraft collided with the power line. The pilot dumped the remainder of the load and the aircraft continued to fly, trailing the power line. After travelling a short distance the aircraft apparently stalled and struck the ground in a nose down attitude. A fire broke out and completely engulfed the wreckage. The pilot subsequently advised that he had temporarily overlooked the presence of the power line. It was probable that on this particular spray run a pole supporting the wire was no longer in the pilot's field of vision. The severed wire became entangled around the right wing and lift strut, resulting in bending of the strut and probably inducing stalling of the wing.

The purpose of the flight was to deliver the aircraft to its new owner. The aircraft had been imported from Papua New Guinea in December 1985 and had flown only a limited amount since that time. The pilot carried out three circuits prior to departure, and made a successful landing enroute for refuelling. However, on touchdown at Bankstown following a normal approach, the nosegear collapsed. Initial investigation revealed that the nosegear downlock had not completed its travel to the overcentre position. In addition, the microswitch was incorrectly adjusted, giving a down and locked indication before the lock was fully engaged. The nosegear had collapsed because of faulty rigging of the gear, which prevented it from completing the full extension cycle. The applied loads had been held by the actuating rods and bellcranks until a bellcrank rod end had failed in overload.

The pilot was carrying out a pre-flight inspection of the aircraft in preparation for an Instrument Rating flight test. He had selected the flaps down, and began operating the hydraulic hand pump to extend the flaps. After a few pump cycles, the right maingear collapsed and the pilot then noted that the gear selector was in the up position. It was suspected that the anti-retraction valve, which is designed to prevent gear retraction on the ground, was unserviceable. However, no fault was discovered. Tests determined that the gear could be unlocked if the hand pump was operated rapidly, and the pilot advised that he had pumped briskly on this occasion. The check list provided by the aircraft operator did not alert pilots to confirm the position of the gear handle before using the hydraulic hand pump. It was not possible to establish why or by whom the gear selector had been placed in the up position.

The pilot had hired the aircraft to fly to Piper's Field with three friends for the day. He was familiar with the strip which is used for glider operations. On arrival in the circuit area, the pilot contacted the local gliding club by radio and was advised that gliders were landing and taking off in a southerly direction. The strip, 686 metres in length, has a one percent average down slope to the south. The wind velocity was reported as 200 degrees at 10 knots. The pilot reported that the aircraft encountered sink on final approach and that he applied power to counteract the sink. The aircraft touched down well into the strip and bounced. The second touchdown was about halfway along the strip and the pilot was unable to stop the aircraft before it overran the strip. The aircraft was damaged when it ran through a ditch which was concealed by long grass.

While the aircraft was being turned left to line up on a runway situated on a black soil plain, the right mainwheel broke through the runway surface, dropped into a concealed hole beneath the crust and bounced out again. The pilot shut down the engines and after inspecting the aircraft elected to fly it to Alice Springs. On arrival the aircraft was placed unserviceable. An inspection by an engineer revealed that the right maingear had been displaced rearward, the gear support structure buckled and the right engine was found to droop 1.5 centimetres.

The pilot had intended to conduct a night freight service to Emerald. There were several thunderstorms in the Emerald area and the pilot elected to divert to Blackwater, 70 kilometres to the east. On arrival in the Blackwater area, the pilot report that he commenced holding at an altitude about 1700 feet above ground level, while he waited for the runway lights to be displayed. The aircraft then entered cloud and severe turbulence was encountered. The pilot stated that his headset was thrown from his head and that he accidently knocked the gear lever into the down position. He said he made no further control inputs. The aircraft struck the ground in a 40 degree turn to the right, at a shallow angle of descent, about 250 metres to the east of the Blackwater runway. The aircraft rotated to the right and slid for about 150 metrtes before coming to rest. The maingear, right engine, aileron and both flaps had been torn from the aircraft during the impact sequence. Reports from ground witnesses indicate that the aircraft was being flown at an altitude of about 400 feet above ground level. It was established that there were thunderstorms in the area at the time but it was not possible to confirm the pilot's report of their severity. The damage to the aircraft suggests that contact with the ground was at a relatively low rate of descent. The investigation did not determine the cause of the accident.

The pilot was taking part in a flying competition consisting of several flying sequences flown from the right hand seat and monitored by a safety pilot/adjudicator occupying the left hand seat. The sequences included a practice forced landing that was commenced from the upwind end of the strip at an altitude of 1500 feet. This sequence was to be conducted without the use of the aircraft instruments. Accordingly all the instruments, including the stall warning indicator, but with the exception of the tachometer and the vacuum gauge, were covered with a piece of cardboard. The pilot stated that he set the aircraft up in a glide for runway 29. Approaching over a tidal lake, and on late final, he realised that he had not adequately compensated for the wind and an undershoot was developing. The safety pilot said that he noticed the rate of sink increase rapidly on late final and when the pilot at the controls did not apply power, he called for a go-around and applied power. However, the mainhweels contacted the water and the aircraft nosed over coming to rest inverted in the shallow lake, 150 metres short of the runway threshold.

The pilot flew to Cervantes on the day prior to the accident to visit some friends. However, upon hearing reports of acts of vandalism at Cervantes airstrip, he inspected several areas on the farm as possible landing sites with the intention of repositioning the aircraft. The next day the aircraft was flown to the farm, where after an airborne inspection the pilot chose the second of two possible landing sites. The aircraft subsequently overshot the intended touchdown point. During the hold off over rising ground, the nose of the aircraft dropped and the aircraft impacted the ground heavily on the nosewheel. The aircraft pitched forward and came to rest inverted. The landing area was unsuitable because of the steeply undulating surface.

The pilot had arranged to meet his son at the Barooga airstrip. Although he had overflown the strip on several occasions he had never previously operated into the strip. After arrival, he was requested to take some friends for scenic flights over the local area. On final approach, on the second of these flights, the aircraft struck powerlines which were strung across the eastern end of the strip, about 85 metres prior to the threshold. The aircraft struck the ground in a nose down attitude 25 metres beyond the powerlines and came to rest inverted. The pilot was unaware of the existence of the powerlines and had not sought the owner's approval or ascertained the strip condition and dimensions before commencing the operation. The poles supporting the powerlines were adjacent to tall trees which resulted in them being difficult to see. Also, it was late afternoon and the approach was being conducted into the west.