Circumstances:

Approaching a reporting point on his cross-country flight the pilot became aware of the failure of a radio navigation aid. Shortly afterwards the pilot was unable to establish radio contact to make his position report. Suspecting an electrical failure but unable to detect the cause the pilot elected to divert to the departure aerodrome. The pilot stated that he turned off all electrically powered services except the VHF radio and was finally able to relay a report through another aircraft. On arrival at Mt Gambier, he made a radio call in the circuit but assumed that the radio was " dead " at that point. Gear was selected DOWN on the downwind leg and the pilot felt that it had extended but reported that he had no gear position indication from the cockpit indicator lights. He then briefly activated the emergency gear extension knob. The pilot continued the circuit for a flapless approach and decided to try and touch the gear on the runway to check if it was extended. A witness on the ground reported seeing the gear extend on the downwind leg and the continuous operation of the aircraft anti-collision beacon. However, when the aircraft was on final approach the witness saw that the main gear was only partly extended, and the nose gear was still in the UP position. His radio calls of warning were not received by the pilot. After a smooth level off for landing the pilot reported feeling the right mainwheel touch down so he reduced power. Almost immediately the gear collapsed, and the pilot was unable to go around from that situation. Subsequent investigation revealed that the source of the electrical failure was a slipping alternator drive belt caused by a worn bracket. The pilot had not flown that type of aircraft for over three months. He was apparently unaware that in order to operate the emergency landing gear system the appropriate knob has to be depressed for about 30 seconds. CAO 40.1.6.1.4.(d) requires the pilot-in command the owner and/or operator of the aircraft to fulfil certain criteria before a proposed flight is undertaken. Evidently none of the parties fulfilled their responsibilities in this regard on this occasion.

Significant Factors:

The following factors were considered relevant to the development of the incident:

1. Electrical system malfunction caused by slipping alternator belt.

2. The operator did not ensure that the pilot was fully familiar with the aircraft and its systems.

3. The pilot lacked familiarity with the aircraft landing gear system.

4. The pilot did not properly use the emergency gear extension system.

Recommendations:

1. It is recommended that the Civil Aviation Authority emphasise the importance of compliance with CAO 40.1.6.1.4 (d) at Aviation Awareness Seminars.

The pilot was spraying a pea crop in calm conditions. A high voltage powerline was strung above a fence bounding one side of the paddock being treated. The pilot knew of its presence and could see it clearly during the spray runs. At the end of the sixth run prior to making the procedure turn, the pilot felt a slight jolt and was surprised when he saw the powerline collapse. The aircraft's deflector wire contacted the powerline and guided it over the fuselage until it was severed by the deflector wire rear attachment bracket on top of the fin. The pilot advised that he misjudged the clearance between the fence and the powerline and later inspection revealed that the line was hung lower than is usually the case.

On arrival at the destination aerodrome, the pilot was unable to obtain a down and locked indication for the landing gear. He noted that when the gear was selected, there was an abnormal noise, and the gear motor only ran for a few seconds. On a subsequent re-cycling, a down and locked indication was obtained, but the pilot noticed a strong smell of hydraulic fluid. A diversion to a more suitable aerodrome was made, where a flypast confirmed that the gear appeared to be extended. The gear warning horn did not sound when the throttles were closed. However, the pilot was unable to move the emergency gear handle from its stowed position when he decided to use this device to ensure the gear was in fact down. During the ground roll, following a smooth touchdown, the right main gear collapsed. The investigation revealed that the right gear up-lock roller was seized. The pilot did not detect this fault during the pre-flight inspection. The landing gear braze rod, the push rod between the actuator and landing gear, was bent and the relevant gear position microswitch was incorrectly adjusted, resulting in a premature landing gear down and locked indication. The landing gear manual extension handle could not be moved because of an incorrectly fitted trim panel. All these mechanical defects were a consequence of inadequate maintenance.

Prior to his arrival, the pilot had contacted the resort to obtain details on the strip at Arkapena as this was the strip closest to the Wilpena Chalet. Among other details given to the pilot was the information that the strip was used frequently. On arrival, the pilot overflew the strip at circuit height for inspection and then made a full circuit before landing. Touchdown occurred at 170 metres into the strip and at about 245 metres along the strip, the nosewheel entered a washaway. The nosegear collapsed shortly afterwards and the aircraft came to rest on its nose and maingear at about 340 metres from the threshold. The pilot of an aircraft carrying out the recovery and repair to the accident aircraft was briefed by the pilot prior to and on arrival by VHF contact from his aircraft radio. Despite the briefing and warning to the recovery pilot, he was unable to detect any washaways from an inspection at 20 feet above ground level, he subsequently made a safe landing by keeping to the right of the strip centreline as advised by the pilot on the ground.

The Taroom aerodrome had recently been equipped with a pilot activated lighting (PAL) system which was due to be commissioned on the evening of 15 October 1988. The pilot, who is a local Council member had flown from his property "Kolane" to Taroom late in the afternoon, to check that the PAL system was functional. He had intended to fly to Taroom the following evening to activate the lights for the official opening celebration, which was planned to be held at the aerodrome. After checking that the system was working the pilot decided to take the opportunity to practice some night circuits and landings before returning to his property. Before departing Taroom he arranged to have two vehicles positioned at his property landing area to illuminate the strip which is 850 metres long, aligned 235/055 degrees magnetic, and 1000 feet above sea level. He apparently intended to check the suitability of the strip for a night landing on his return. The aircraft was observed to fly over the strip in a north-easterly direction and then make a left turn. The aircraft was then seen to descend and the sound of impact was heard by the occupant of a vehicle near the strip. The aircraft had impacted the ground whilst in a descending left turn at a groundspeed of approximately 125 knots. Initial impact was in a clearing near trees. The aircraft slid 91 metres before the left wing struck a large tree and was torn off. The aircraft slid another 45 metres before coming to rest and catching fire. The pilot was thrown from the aircraft while still strapped to his seat and was able to move himself away from the immediate vicinity of the fire before help arrived. The pilot has no recollection of events immediately prior to the accident. There is no indication that the aircraft was not functioning normally at the time of the accident. The weather was fine, there was a light northerly breeze, and there was no moonlight. Indications are that the pilot may have become disorientated whilst attempting to carry out a visual circuit when there was no visual horizon. The landing area did not meet the requirements for night operations published in the Visual Flight Guide.

Circumstances:

The aircraft was being used for dual training and was operating in the circuit, having been airborne for about 45 minutes. During a turn onto the crosswind leg the engine partially lost power. The instructor immediately took control as the power was inadequate to maintain height and initiated a turn for landing on the reciprocal runway. On the approach, the aircraft struck trees bordering the edge of the strip and dived vertically to the ground. The instructor's seat attachment was damaged during the collision with the trees, prior to ground impact. Examination of the engine's spark plugs indicated the front cylinder had ceased to deliver power. The partial loss of power was the result of dirty fuel. Contamination was found in the float bowl of the front cylinder carburettor, in the fuel filter, and in the fuel line between the fuel tank and filter. The contaminated motor vehicle fuel was purchased from a nearby service station on the day prior to the accident. Two stroke oil was mixed with the fuel by the aircraft operator and not adequately filtered before being added to the aircraft fuel tanks.

Significant Factors:

The following factors were considered relevant to the development of the accident:

1. The engine suffered a partial loss of power during the crosswind turn in the circuit.

2. The engine power output was insufficient to enable to the aircraft to reach the airstrip.

3. The partial power loss was due to fuel starvation as a result of contaminated fuel.

4. The fuel was not adequately filtered before it was added to the aircraft fuel tanks.

Recommendations:

It is recommended that the Australian Ultralight Federation remind all pilots and operators, of the requirements and procedures to maintain stringent fuel quality control.

After landing, as the aircraft turned left into the taxiway, the left maingear collapsed. Inspection revealed that the drag link centrebolt had failed. Examination of the bolt revealed that it had failed due to fatigue, which had initiated from pit corrosion along the shank of the bolt. It also displayed signs of in-service wear which possibly contributed to the failure. This aircraft reportedly operated from rough, uneven dirt strips on a regular basis.

After flying in cloud for 15 minutes of a 17 minute cruise at 18000 feet descent was commenced to the destination aerodrome. As the aircraft was passing 7800 feet on descent in cloud and light to moderate rain the cockpit warnings alerted the crew to a failure of the left engine. However, before any rectification action could be undertaken by the crew, all warnings ceased and power was observed to be restored. The crew reported that although approximately 15 minutes of cruise flight had been in cloud, the only visible ice accretion was a very light rime ice coating on the leading edge of the wings. There was no ice visible on the propellers or the nacelles. The investigation noted that this and all other reported incidents involving uncommanded engine shut down (flameout), occurred either when the aircraft was in moderate to severe icing and free moisture or shortly after exiting those conditions. Tests carried out at certification failed to reveal the source of a critical ice buildup in the intake duct or engine. It was revealed that a propeller was not fitted to the test unit during the ice tunnel tests and subsequent post certification tests have suggested that an unusual swirl which has been detected coming from the propeller may be a contributing factor causing a blanketing effect in the intake duct. Depite early modifications to the Electronic Engine Control Unit, the Handling Bleed Valve and the Fuel Nozzles further cases of uncommanded engine shutdown under similar weather conditions were experienced. It is considered that these modifications by themselves are not sufficient to prevent a recurrence of the flameout problem. Subsequent tests by the manufacturer using video camera equipment installed in the intake duct revealed ice buildups on the unheated flexible seal between the intake duct and the engine flange. The tests confirmed that when a critical mass of ice was reached the buildup would break off and be ingested by the engine resulting in power fluctuations. It is considered that the inflight power fluctuation incidents have been caused by flameouts originating from ice ingestion in the engine. It is considered that the methods adopted to satisfy the certification requirements for icing failed to adequately address the area of intake icing. Had they done so, the formation of ice on the unheated flexible seal between the intake duct and the engine flange would have been discovered prior to certification.

At 0341 hours EST on 6 July 1989, Beech 70 Queenair aircraft registered VH-XAE collided with high voltage power lines and descended rapidly, contacting the ground three kilometres north-east of Tolmie. The pilot, who was the only occupant, received fatal injuries. There was no fire. The aircraft was on a flight from Sydney to Melbourne cruising at 8000 feet. Persons in the accident area heard an aircraft flying very low over their houses, then observed a flash of light and heard the sound of ground impact. A ground search was commenced but due to falling snow and very poor visibility the wreckage was not found until about 0745 hours in daylight. The elevation of the ground at the accident site was approximately 2700 feet above sea level. The accident site was located at co-ordinates 36`55'south, 146`17'east.

After having inspected a property, the pilot and his passengers returned to the aircraft to prepare for DEPARTURE. A storm was approaching the strip from the north and a 10 to 15 knot crosswind prevailed at the strip. A take-off into the east was commenced, the aircraft became airborne and as it crossed the upwind end of the strip, it was affected by a sudden gust of wind. The aircraft yawed to the right, lost altitude and struck the ground, before coming to rest in a ploughed paddock. At the time of the attempted take-off the location of the approaching storm was conducive to the presence of strong downdraughts or possibly microbursts in the vicinity of the strip. The pilot elected to commence the take-off because he was concerned that heavy rain at the strip would have rendered it unserviceable.