Two CA25 aircraft, VH-ZVC and VH-DLY, were operating in the circuit using runway 18. The pilots, both solo students, had been communicating with each other on the mandatory broadcast zone (MBZ) frequency. The pilot of ZVC had just turned final when DLY was turning base. The pilot of ZVC had reported base for a full stop landing. The pilot of DLY also reported base for a full stop landing. At no time did either pilot hear any other aircraft transmissions. As ZVC touched down the pilot became aware of a large twin engined aircraft approaching head on at high speed after it had landed on runway 36. The pilot of ZVC applied full power and went around passing over the top of the twin. The pilot of DLY was unaware of the presence of the twin and landed just as it was exiting the runway. As the twin engined aircraft VH-OCF taxied onto the apron the pilot apologised to the other pilots on the MBZ frequency.

The pilot of OCF said that he was flying on a scheduled service from Brisbane to Maroochydore. Whilst enroute he noticed the wind was from the north-east and planned his approach to land on runway 36. The pilot stated that during the descent he made a number of transmissions approaching the MBZ but heard no response. The Maroochydore MBZ has the same lateral dimensions as the control zone. He did not consider it unusual that there was no response, as frequently there is no other traffic, and if there is, he is usually advised by Brisbane Centre. After having cancelled SAR with Brisbane Centre, and when lined up on short final for runway 36, the pilot detected movement at the far end of the runway. He said a small dark object had risen from the ground which he initially thought was a bird, but he then realised it was a small aircraft. He then noticed another aircraft on final approach for runway 18 as he vacated runway 36. He then noticed that his VHF was selected to 124.8 mhz instead of the MBZ frequency 124.4 mhz.

The pilot had just bought the aircraft and was delivering it to his home. The previous owner had not flown the aircraft extensively and was unable to assist with performance and fuel information. As a result, the owner used the cruise performance information available in the pilot's handbook. This information showed an endurance of 7.9 hours and a range of 845 miles.

After refuelling to full tanks at Hughenden the pilot intended flying to Barcaldine and refuelling there. The turbulence enroute was considerable so the pilot elected to depart early the next morning to avoid the turbulence. He dipped the tanks and found that they were over half full. Since he considered that this would give him four hours of endurance he departed for Roma without refuelling. The ground speed obtained during the flight would have required a flight time of 223 minutes to Roma. While enroute, the engine failed due to fuel exhaustion. He conducted a forced landing on a road and obtained fuel to complete the flight.

The pilot later learned that the endurance figures quoted in the handbook were optimistic. He also found that the actual fuel used during flights was much higher than he had expected. By completing full flight plans he has been able to establish accurate fuel consumption figures for his aircraft.

After the landing the pilot attempted to activate the ELT using the remote control on the aircraft instrument panel. The unit did not operate because of a flat Lithium battery in the remote-control unit. After the battery was replaced, the unit was able to function correctly.

The Piper Pawnee aircraft was conducting spraying operations on a property. The landowner had provided a map of the treatment area, and the pilot had conducted an in-flight inspection. Spray runs were to be conducted at right angles to a powerline running along the boundary of the area to be treated, with the aircraft climbing over the powerline before carrying out a procedure turn and descending to commence another run.

The aircraft was fitted with a Global Positioning System (GPS) to provide track guidance to the pilot during the spray runs. The pilot reported that during the initial spray runs his attention was drawn to the GPS Marking System due to alignment errors. Following the procedure turn after the fifth spray run, the pilot reported he momentarily forgot about the presence of the powerline and descended into it. The landing gear snagged the wire, causing the aircraft to lose airspeed and strike the ground in an almost level attitude. The left wing and fuselage were damaged during the ensuing ground run. The pilot, who was wearing a full harness, was unhurt.  An Emergency Locator Transmitter (ELT) was not fitted to the aircraft.

The pilot had flown the aircraft from Porepunkah to Wangaratta where he added fuel. He then continued the flight as planned to Hoxton Park. On the evening before the return flight to Porepunkah the pilot travelled to Hoxton Park to check the aircraft. He used a dipstick to calculate the fuel remaining and estimated there was a total of 200 L, 90 L in the right fuel tank and 110 L in the left. He considered this was sufficient for the flight and declined the opportunity to add more fuel at that time.

The next morning the pilot completed a pre-flight inspection of the aircraft, including another check of the fuel quantity. He again estimated the fuel remaining to total 200 L. Approximately 90 minutes after departure, whilst the aircraft was cruising at 6,500 ft, the engine started to misfire, then experienced a complete loss of power. A forced landing was carried out following the pilot's unsuccessful attempt to restore power. The aircraft landed heavily and skidded along the ground for about 90 m, during which time the nose landing gear separated from the fuselage. The pilot and three passengers escaped without injury.

Weather conditions at 6,500 ft at the time of the accident were fine, with a temperature of 1 degree Celsius, and a dew point of minus 10 degrees Celsius.

An on-site examination of the aircraft indicated no evidence of an engine defect which may have contributed to the accident. No fuel was found in either fuel tank, and only a small quantity could be collected from the remaining fuel system. There was no evidence of fuel having vented or leaked from the fuel cells or the engine area, nor were there indications of excessive fuel consumption.

The recent flight history of the aircraft and relevant fuel purchases were examined. It was determined that there would most likely have been a total of about 100 lts remaining in the fuel cells when the pilot added a further 122 lts at Wangaratta. Using average fuel consumption figures for the aircraft type, and flight times obtained from the pilot, it was estimated that there had been insufficient fuel on board to complete the flight to Porepunkah.

When the pilot had refuelled at Wangaratta, he observed fuel bubbling up from each fuel inlet and assumed the fuel cells were full. He did not use a dipstick to confirm the quantity, nor did he look into the fuel inlets to observe the fuel levels after he removed the fuel nozzle from each inlet. There would have been about 222 L on board the aircraft when the pilot departed Wangaratta and not 303 L, as should have been the case if the fuel tanks had been filled to capacity. Subsequent observations of fuel quantity indications on the dipstick may have been influenced by this false assumption.

The pilot was mustering cattle. He carried two observers in the aircraft. The weather was warm, windy, gusty and moderately turbulent. Hoping to turn the lead cattle towards a bore, he commenced a descent from about 140 ft above the ground while turning downwind. His intention was to level off at about 30 ft abeam the cattle. He planned to maintain an indicated airspeed of 75 to 80 kts with 20 degrees of flap. However, he was unable to arrest the rate of descent through 30 ft. He found himself too low to bank the aircraft successfully away from the cattle for fear of hitting a wing on the ground. With a left quartering tailwind, the aircraft drifted towards the herd. The pilot tried yawing the aircraft and pulling up to avoid the cattle, but the left main landing gear wheel struck a heifer across its back.

Despite tearing off the left main wheel, bending the landing gear leg aft, and killing the heifer, the aircraft remained airborne and eventually gained altitude. The pilot then smelt fuel, which was leaking from a fuel line, broken by the dislodged left landing gear leg. He declared an inflight emergency to flight service and to Helen Springs homestead. Homestead personnel quickly ran a grader over the airstrip to smooth it out and hopefully make it safer for the emergency landing. The pilot managed to land the aircraft without further damage.

The pilot probably encountered low windshear.

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 pilot reported that he was conducting sheep spotting operations at 500 ft above ground level when the engine suddenly lost power. He was forced to complete an emergency landing in rough terrain, damaging the aircraft in the process.

The pilot had refuelled the aircraft to full tanks and conducted a water drain test 45 minutes flying time prior to the power loss.

The carburettor was removed, tested and inspected. On the test bench, the carburettor flooded each time it was tested. The inspection disclosed some faults that probably led to the flooding. The float level had been incorrectly set, there was significant wear in the float attachment pin and the floats had been making contact with the carburettor body and the head of the needle valve had been repaired using silver solder. Additional tests also indicated that it was possible for the needle valve to jam in the closed position, starving the carburettor of fuel. The head of the needle valve was badly worn. This permitted it to become jammed in a corresponding wear mark on the carburettor body. Other faults, such as the use of locking wire instead of a split pin to secure the float pin and disintegration of the accelerator pump leather plunger were also evident.

An inspection of the aircraft logbooks indicated that the carburettor float level had been adjusted by a LAME 12 flying hours prior to the power loss. Float adjustment requires the carburettor to be opened. Some of the faults, which the inspection indicated had been present for a considerable time, should have been apparent during the adjustment. They were not corrected.

It is probably that the faults in the carburettor caused it to be starved of fuel or to flood and one of these situations led to the power loss.

The helicopter was in level flight at 500 ft above ground level and nearing its destination when, without warning the engine stopped. The pilot conducted a forced landing into a clearing, damaging the right skid. Post flight inspection revealed only a small quantity of fuel in both tanks.

The pilot later confirmed that the helicopter had run out of fuel. He said he had been "pushing" a headwind and had flown a higher indicated airspeed to maintain a reasonable ground speed. He was surprised that the actual fuel consumption was 38 Litres/hr instead of the 32 he planned on. He also said that the Fuel Low warning light was unserviceable and that the fuel gauges were inaccurate.

VH-OZM and VH-OZN were on descent OCTA approaching Cowes. OZN was the leading and lower aircraft, and both pilots were aware of and communicating with each other and the pilot of OZM had OZN in sight ahead and below. Both pilots were communicating with Melbourne Centre. When the two aircraft were on descent, the controller that he had lost the mode C altitude readout for OZN.

As they approached Cowes, the pilot of OZM diverted his attention to some cockpit duties. Shortly afterwards, he heard the pilot of OZN give his Cowes position report and at that time OZM was still four miles from Cowes by GPS. When the pilot of OZM next sighted OZN, after passing Cowes, the two aircraft were at the same level and laterally separated by approximately 100 metres.

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.