The pilot had only just taken delivery of the helicopter. After attending a party he invited an acquaintance to inspect the aircraft and listen to a compact disc player which was installed. The pilot stated that the helicopter battery did not seem to have much charge and since he knew the aircraft was to be used in the morning, he decided to start the engine. He believed that there was a note in the Flight Manual stating not to leave the engine running too long without engaging the main rotors. He therefore engaged the rotor and the next thing he could recall was that the helicopter was on its right side. The pilot, although the owner of the helicopter, was not qualified or authorised for night flying. He had consumed some alcohol at the party, and there is some doubt as to whether a takeoff had been intended. Nevertheless, by starting the engine and engaging the main rotor, the pilot should have been aware that an inadvertent takeoff was possible.

Circumstances:

The pilot reported that whilst enroute from Essendon to Wonthaggi he descended to the lowest safe altitude of 3600 feet above sea level, lowered the landing gear, reduced power and airspeed to counter the effect of turbulence and entered a holding pattern to the south south west of the Wonthaggi navigation aid. During the holding pattern the aircraft descended until it collided with trees that were 865 feet above sea level. The weather at the time included gale force winds, rain, and low cloud. There were no thunderstorms or microbursts in the area, however, other aircraft reported a very low cloud base and severe turbulence. A few minutes prior to the accident ground witnesses, south south west of the accident site, reported an aircraft matching the description of VH-SDV, flying below a low, misty, ragged cloud base. There was no record of another aircraft in the area at the time. Information was available which indicated that the aircraft had descended below 3600 feet during the approach to Wonthaggi. The passengers reported that the pilot gave no indication of any problem or danger. Until the impact, they believed the aircraft was descending normally for a landing at Port Welshpool. No aircraft defects were found which may have been factors in the accident. The investigation indicates that the pilot attempted to fly under the low cloud base, in order to reach the Port Welshpool destination where weather conditions were earlier reported to have been partially sunny. Port Welshpool is not serviced by an approved navigation aid.

Significant Factors:

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

1. The pilot attempted to descend below the cloud base, hoping to achieve visual flight conditions to continue to his destination.

The aircraft was cruising just inland of the beach at 1500 feet when the pilot noted smoke, accompanied by a strong burning smell entering the cabin from the lower right hand side air vent. Almost immediately the engine suffered a complete loss of power. The pilot carried out a successful wheels-up forced landing on the beach. A fire which had been burning in the nose wheelwell area had apparently been extinguished by seawater and wet sand during the landing slide. Inspection revealed that chaffing had occurred between an electric cable and hydraulic line situated in the wheelwell. Arcing from the electric cable burnt through the hydraulic line, and hydraulic oil under pressure escaped in a fine spray and was ignited by the arcing. This created a torching effect which was directed at the fuel strainer. The heat caused the fuel in the strainer to boil, developing a vapour lock and disrupting the fuel flow to the engine and causing the subsequent engine failure. The chaffing of the cable on the pipe was in such a location that it would have been difficult to see during normal periodic or pre-flight inspections.

A trench had been dug across the apron during the installation of aerodrome lighting. It had been back filled with earth. Whether the compacting was inadequate or whether the rain had been exceptionally heavy is not known, but heavy rain had made the earth fill very soft. The pilot landed just after a very heavy rain shower had passed through the area. There was about 2 cm of water covering the ground which made it near impossible to see the trench. When the aircraft's nosewheel entered the soft earth the aircraft veered sharply to the left and travelled about two metres before the nose gear hit a concrete pad and collapsed. Because the trench was almost impossible to see from the cockpit of the aircraft it is considered that it was a hidden hazard. The trench had not been marked by unserviceability cones. This accident was not the subject of an on-site investigation.

Circumstances:

The aircraft was nearing the completion of a scenic flight, maintaining about 800 feet above ground level, when the engine power reduced to 20 inches hg manifold pressure. The engine continued to run smoothly but failed to respond when the pilot advanced the throttle. All other means attempted by the pilot to restore the lost power were unsuccessful. The aircraft, which had a full complement of persons on board, was too heavy to maintain height under these conditions. As it was flying over forest the pilot turned the aircraft towards the south-west where a more favourable open area, with a road and an airstrip, was available. This entailed having to cross an escarpment, but due to the aircraft's rate of descent insufficient height remained, committing the pilot to a forced landing in an unsuitable area. The pilot transmitted a distress call, gave the passengers a thorough briefing and prepared the aircraft for the forced landing. The aircraft was slowed down and allowed to sink slowly into the forest, contacting the first tree about seven metres above ground level. It then continued through the trees for 40 metres before coming to rest inverted on the forest floor. All passengers evacuated from the aircraft and were rescued by a helicopter which had responded to the distress call. Inspection of the engine determined that it was capable of developing full power at the time of the accident. The throttle cable was found to have separated from the cast bronze throttle control lever at the fuel/air metering unit on the intake manifold. The serrated steel bush in the throttle control lever at the cable attachment had become loose, causing the hole to wear elongated which reduced the edge distance from the hole to the end of the control lever sufficiently for it to fail when the throttle was opened. This probably occurred during the last take-off. During flight, the bush, which was still attached to the cable ball end by the bolt, was probably in such a position as to operate the lever when the throttle control was moved to reduce power for climb and cruise. As the flight progressed and the cable separated from the lever, in-flight movement and vibration would have moved the throttle towards the closed position, with the subsequent reduction in power. Further inspection found that the assembly of the cable to the lever was incorrect, with the washer from under the bolt head being omitted. This reduced the bearing area at the bolt head to the control lever, with the possibility that the bolt may have only been clamped to the bush assisting any movement of the bush in the lever. Once the steel bush started moving in the softer bronze material the rate of wear would have been rapid. The aircraft had flown 85 hours since the last periodic inspection, at which time it may have been possible to detect the first signs of wear between the bush and the control lever if information advising of this type of fault had been available.

Significant Factors:

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

1. Incorrect assembly of the washers on the control cable attachment bolt may have allowed the bush to start moving in the lever.

2. The bush became loose in the control lever, with the subsequent wear elongating the hole allowing the control lever end to fail.

3. The throttle control cable separated from the throttle control lever.

4. The throttle closed sufficiently during flight to reduce engine power.

5. The aircraft was too heavy to maintain flight.

6. The aircraft was operating over an area unsuitable for a forced landing.

7. Wear between the bush and the lever may have been detectable during the previous periodic inspection if advisory information had been available.

Recommendations:

It is recommended that the Civil Aviation Authority consider issuing an Airworthiness Directive (or Advisory Letter) to all owners and operators of aircraft fitted with Teledyne Continental fuel injected engines:

1. Advising of the need for correct installation, assembly and attachment of fuel and mixture control rod end nuts, bolts, and the location of washers to control lever arms, and

2. Instruction for the critical repetitive visual inspection of the lever arm bolt holes and bushings for wear, and bushings for looseness, with the control rod bolt and washers disassembled.

The pilot hired the aircraft to make a short local pleasure flight with some friends on board. The aircraft was parked at the southern end of the airfield, pointing north and aligned with the centre of the 1300 metre grass strip. The pilot reported that he started the engine and completed normal engine runup and pre-takeoff checks. He then manoeuvred the aircraft out of the parking position to check for other aircraft on final approach. A takeoff into the north was then commenced. After what the pilot considered was a normal ground roll, the aircraft became airborne. He initially allowed it to accelerate close to the ground before commencing to climb. At an altitude of about 100 feet above the ground and an airspeed of about 60 knots, the engine began to run very roughly. The pilot landed the aircraft back on the strip and commenced braking. He then became aware that the aircraft was not going to stop before the fence at the northern end of the strip. Accordingly, he applied power in an attempt to fly over the fence. This attempt was not successful. The aircraft hit the top wires of the fence and an adjacent gorse hedge, coming to rest 50 metres further on with the nose gear detached. An examination of the engine revealed a number of faulty spark plugs. An opinion was obtained from an engine specialist that the condition of the plugs was consistent with the rough running reported by the pilot. Weather conditions had not been conducive to the formation of carburettor icing.

Circumstances:

The pilot was relatively inexperienced on the aircraft type and bush flying. She had flown into Lamboo Homestead airstrip during the morning to drop off her employer. She had then flown over to the newly graded strip at Old Lamboo where her employer's mustering team was camped. After approximately one hour on the ground, the pilot decided to do a circuit of the airfield with one of the mustering team as a passenger. She had not landed at this airfield before and did not consult the aircraft performance charts. The performance charts indicated that twenty degrees of flap was required and that the available take-off distance required to clear the obstacles at the threshold was marginal. The pilot elected to make a flapless take-off. When approximately 2/3 along the 700 metre strip, and the aircraft did not appear to be accelerating normally, the take-off was abandoned. The pilot expected that the aircraft would stop within the remaining distance, however, the aircraft did not stop as expected and continued beyond the end of the strip. The aircraft was substantially damaged before coming to rest approximately 110 metres past the prepared threshold. Subsequent investigation indicated that the pitot tube was partially blocked, and this had caused the airspeed indicator to under read.

Significant Factors:

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

1. The pilot attempted operation beyond experience/ability level.

2. The pilot did not use the aircraft performance charts to determine if runway length was adequate.

3. The pilot did not use the correct flap setting.

4. The pilot misjudged speed and obstacle clearance required and ran off runway.

5. The pitot tube was partially blocked causing the Air Speed Indicator to under read.

Information provided by the pilot indicated he had planned to land the aircraft in a paddock used by crop dusting aircraft. He contacted the owner of the paddock and determined that it met the requirements for his aircraft. The pilot was advised that a set of powerlines crossed the approach end of the paddock and he requested the owner to park his car underneath these powerlines to mark their location. When the pilot arrived over the strip a car was parked near the approach end where the pilot thought the powerlines were and he assumed the owner had acted on his request. After carrying out an Authorized Landing Area inspection during which he did not sight the powerlines the pilot made a normal approach. He kept well clear of the car but the aircraft collided with the powerlines on late final approach and touched down heavily. Information provided indicated that the owner of the paddock had parked his car more than 20 metres downwind of the powerlines for reasons which were not determined and this had given the pilot the wrong impression of their location. This accident was not the subject of an on scene investigation.

Circumstances:

Approaching top of descent at 10,000 feet, the pilot noticed smoke coming from under the instrument panel. The smoke rapidly increased in density until it was almost black in colour with a very strong petrochemical, choking odour. The pilot commenced a rapid descent and turned the aircraft towards the coast. He switched off all electrical services as flames appeared under the instrument panel. He extinguished these flames with the cockpit fire extinguisher and opened the cockpit window to provide fresh air. The pilot switched on the electrics to transmit a mayday call and talk to a company aircraft about 10 miles behind. However, flames reappeared so the electrics were again selected off. At no time did any circuit breakers operate. Passing about 7,000 feet in the descent, the engine failed without warning and could not be restarted. The pilot manoeuvered the aircraft for a wheels up landing on a dry tea tree swamp. On final approach, he unlatched the door to aid in emergency evacuation. The passenger in the right front seat attempted to exit the aircraft but was restrained by the pilot. This passenger had to keep her feet on the seat during the final 300 feet to avoid the flames. The pilot planned a high-speed approach to ensure he did not undershoot the intended landing area. On short final, he selected full flap and, probably due to the short circuit behind the instrument panel, full flap was obtained. He also opened the air vents which increased the intensity of the fire but gave him good vision. After striking some small trees on final, the aircraft slid about 90 metres before coming to rest. All occupants evacuated safely through the doors. The pilot estimated that the cabin was engulfed in flames within 30 seconds of the aircraft stopping. It is most likely that the fire started as a result of electrical arcing caused by the failure of insulation on the wire carrying electrical power from the starter relay to the ammeter. The fire burnt through the magneto wire insulation, grounding the wires and stopping the engine.

Significant Factors:

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

1. The insulation on the starter relay to ammeter wire on the cabin side of the fire wall rubbed through.

2. An electrical short circuit developed, resulting in arcing which started a fire under the right side of the instrument panel.

3. The fire spread to the left side of the instrument panel and burnt through the magneto wire insulation resulting in engine failure.

4. The aircraft landed in unsuitable terrain.

Circumstances:

The Examiner-of-Airmen was flight testing a pilot for his commercial helicopter licence. At 3000 feet above sea level the Examiner closed the throttle without warning, to simulate an engine failure. The Examiner had preselected what he considered to be a suitable clearing within autorotative distance for the practice forced landing. The terrain was undulating, tree covered but with scattered clearings. Ground level averaged 1500 feet above sea level. The candidate was not expecting a simulated emergency; he was not holding the collective lever. However, he performed a normal entry into autorotation straight ahead. The main rotor RPM initially reduced to the bottom of the green arc (390 RPM). Instead of reducing to idle RPM, the engine stopped when the throttle was closed. The Examiner immediately took over control of the helicopter and turned right into wind and towards the clearing. Rotor RPM was soon established in the middle of the green arc (at about 450 RPM) but there was no response to the throttle. During the descent towards the clearing, the pilots unsuccessfully attempted to restart the engine. During the autorotative descent the helicopter undershot the clearing. At the tops of 15 metre high trees, about 20 metres short of the clearing, the Examiner flared the helicopter and applied some of the collective pitch to reduce the rate of descent. As the helicopter settled through the trees with about 20 knots forward speed, he pulled the remaining collective pitch. At about five metres above ground level the helicopter settled on to saplings at the edge of the clearing. The saplings cushioned the descent and diminished the forward speed. The main rotors struck the ground, and the helicopter came to rest on its right side about eight metres into the clearing. The two pilots were wearing a full harness. Both inertia reels locked (as designed) at ground impact. Both harnesses severed at the point where the straps exit the reels. The investigations determined that both reels had been installed upside down before the Australian Certificate of Airworthiness was issued in 1988, despite the existence of a detailed CAA Airworthiness Directive warning that erroneous installation could jeopardise restraint in an accident. Engineering bench tests and subsequent engine ground runs revealed that fuel injector servo fuel flow at engine idle setting was excessively rich. The fuel injector servo had been fitted to the helicopter six days before the accident, and the helicopter had successfully carried out several simulated engine failures in training during that period. There is little doubt that the engine stopped as the result of a "rich cut" when the Examiner closed the throttle to simulate an engine failure.

Significant Factors:

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

1. The fuel injector fuel flow was excessively rich at engine idle.

2. The engine stopped during the simulated engine failure because of a "rich cut".

3. It is more difficult for a pilot to judge a helicopter's autorotative glide distance over undulating terrain than over flat terrain.

4. The Examiner-of-Airmen misjudged the range capability of the helicopter's autorotative descent.