Circumstances:

The pilot reported that he took off into the north towards trees about 50 metres from the lift off point. He accelerated the helicopter through translational lift speed but had to climb soon after to avoid the trees, which were some five metres high. Once above the trees, the helicopter began to descend and lose performance. The pilot applied full collective pitch but was unable to prevent the aircraft descending into the trees. The pilot reported that winds in the area had been predominantly from the south for a number of days. Although conditions at ground level at the time of the take-off were fairly calm, there may have been a southerly wind component above tree-top level. This, coupled with the relatively high operating weight of the helicopter might have been sufficient to cause the loss of performance described.

The flight was intended to return patients to their home area following medical treatment in Melbourne. After an apparently normal take-off, the aircraft ceased climbing at about 100 feet above ground level. In response to a query from the Tower, the pilot advised that the left engine had failed, that he was feathering the propeller and would return for landing. The aircraft was seen to be deviating to the left, towards a large array of power lines. These lines extend from about 40 feet to 90 feet above the ground, and as the aircraft converged with the array it was probably below the height of the upper wires. The aircraft then suddenly veered to the left and subsequently struck the ground in a steep nose-down attitude. A fire broke out on impact and destroyed much of the wreckage. The final manoeuvre performed by the aircraft was typical of that which occurs when one engine of a twin-engine aircraft is producing considerably less power than the other, and airspeed is reduced to below that required to maintain directional control. The pilot had reported that the left engine had failed, and the loss of control as described by witnesses was consistent with a reduction of power from this engine, combined with low airspeed. The investigation of the accident was hampered by the extent of the fire damage. However, an extensive technical examination did not reveal any evidence of a defect or malfunction with either the engines, the various systems or the airframe which might have contributed to the accident. Although the pilot had indicated that he was feathering the left propeller, it was determined that the propeller was not feathered at the time of the accident. It was not possible to establish if the pilot had subsequently elected not to initiate feathering action, or whether such action was initiated too late for it to be completed before impact with the ground. The reason for the loss of performance reported by the pilot could not be established. It is likely that while the aircraft was being manoeuvred to avoid the power lines and return for a landing, the airspeed decayed to below the minimum required to enable adequate control of the aircraft to be maintained. At the point where control of the aircraft was lost, there was insufficient height available for the pilot to effect recovery. The reason continued flight was attempted, rather than a controlled forced landing in open areas prior to the power lines, could not be determined.

The pilot planned to arrive at his destination 10 minutes before his estimate of last light. However, after deviating around rain showers and conducting an aerial inspection of a prospecting site, the pilot's arrival was delayed until 10 minutes after last light. An approach was made to the unlit strip using the aircraft landing light for guidance. After flaring at about 15 feet agl the pilot waited for the touchdown but the aircarft stalled and struck the ground nosewheel first, collapsing the nosegear. Facilities were available at the departure aerodrome which would have allowed the pilot to obtain a weather forecast and an accurate time of last light. Despite the fact that the pilot had no night flying experience he choose to land the aircraft without requesting an emergency flare path to be laid.

Circumstances:

The pilot reported the aircraft had been flying for about two hours in low-level operations over his property. Shortly after placing the helicopter into a steep climbing turn the engine suffered a complete loss of power at a height of about 150 feet, and an airspeed of 30 knots. The aircraft was over scrub covered terrain. In the resulting forced landing, the tail boom was severed by the main rotor, and a landing skid was buckled. The pilot said there was an estimated 20 litres of fuel remaining but suspected the engine may have lost power due to fuel starvation as a result of the manoeuvres performed. This accident was not the subject of an on-site investigation. The information contained in this report was supplied by the pilot.

The aircraft was stolen from the Elcom works compound. During the attempted takeoff the passenger jumped from the aircraft and was struck by the rotor blades as the helicopter fell onto its side. This accident was not the subject of a formal on scene investigation.

The aircraft was on charter to Australian Airlines operating as Flight Number AUS656. The aircraft was inbound to Sydney via the 07 Localiser. Approaching 7000 feet, on first contact with Sydney Approach South, the aircraft was instructed to descend to 4000 feet, not below the DME (Distance Measuring Equipment) steps. The DME Arrival Procedure indicates the aircraft should not descend below 5000 feet until 19 DME, to maintain separation from uncontrolled traffic below the DME steps. At 22 DME, the aircraft's altitude readout (on the Sydney Approach Radar) indicated, and was confirmed as, 4100 feet. There was no known traffic confliction. The DME Arrival Procedure for Sydney is not in accordance with ICAO Doc 8168- Ops/611 and may not be used by international operators. However, the aircraft was operating on a domestic flight plan, and only the three letter call sign and domestic flight number were on the flight progress strip held by the Sydney Approach Controller. Since this incident, the Civil Aviation Authority have issued an instruction that DME Arrival Procedures, which are not in accordance with ICAO standards, will not be issued as clearances to any aircraft, domestic or international.

After reaching a height of about 200 feet agl on a winch launch, the glider was observed to enter a shallow dive. The drogue parachute was seen to inflate above the inboard section of the left wing and then trail behind the glider with the tow wire draped over the top of the wing. The glider entered a left turn which developed into a spiral dive. Partial recovery was effected but the aircraft impacted the ground in a nose-down attitude. The pilot was relatively inexperienced and was performing his fourth solo winch launch. During the launch the aircraft exceeded the climb speed limit and the pilot atempted to signal this fact to the winch operator by the normal method, which involves lowering the nose of the aircraft prior to yawing it from side to side. However, the pitch change used was larger than normal, unloading the tow cable and resulting in a "back release". The length of cable between the attachment ring and the drogue parachute was considerably shorter than that recommended and increased the probability of an uncommanded release of the tow cable.

Circumstances:

The flight to Melbourne was planned via Canberra Corryong and Eildon Weir with a cruising level of 8000 feet. The weather forecast for the route included scattered cumulus cloud to 10000 feet and areas of broken strato cumulus cloud from 3000 to 7000 feet. The forecast freezing level was 6500 feet. The aircraft was not equipped with wing or propeller de-icing systems but had the standard pitot heater as well as a stall warning vane heater. The flight at an indicated airspeed of 150 knots proceeded uneventfully apart from some ice buildup on the windscreen and wings which seemed to clear when the aircraft exited from cloud. However shortly after passing Corryong the pilot felt a vibration through the aircraft. The autopilot was disengaged but the vibrations rapidly worsened and the aircraft suddenly rolled and began to lose height. At this stage, the airspeed was still indicating 150 knots, and the aircraft was turning right in a right wing low attitude. The pilot recalled applying left rudder and moving the yoke forward and sensing that the airspeed which was then indicating zero was increasing. Control of the aircraft was regained at about 5500 feet (Lowest Safe Altitude for the sector was 6700 feet). The pilot found later that the pitot heat circuit breaker had popped thus deactivating the pitot heater. This would have allowed the pitot head to become iced up and cause false airspeed indications. It was not until after the incident that the pilot thought to look at the No 2 Air Speed Indicator (ASI) on the right instrument panel. This instrument which operates independently of the ASI on the left instrument panel was operating normally. Normal operation of the pilot's ASI did not return until the aircraft was on descent to Melbourne.

Significant Factors:

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

1. The aircraft was operating at a height and in weather conditions conducive to airframe icing.

2. The pitot heat circuit breaker had popped allowing the pitot head to ice up and cause a false airspeed indication.

3. The pilot was not aware that the airspeed indication was incorrect.

4. The pilot lost control of the aircraft when it stalled because of an excessive buildup of airframe ice.

The pilot reported that prior to touchdown all gear down indications were normal. Shortly after touchdown the right gear collapsed and the aircraft came to rest on the right wing tip, 6 metres from the edge of the runway. A subsequent inspection found that the right gear collapsed because it failed to lock overcentre. This was probably caused by the inadequate lubrication of the landing gear system.

Circumstances:

Prior to landing the pilot intended to carry out an inspection of the flight strip for possible obstructions. The inspection was to be performed at 500 feet above ground level, with ten degrees of flap selected. During the inspection, the aircraft suddenly began to "sink" rapidly. Thinking the engine had suffered a loss of power, the pilot selected full throttle and lowered full flap in preparation for an emergency landing. Although the engine accelerated to full power, the aircraft did not respond to other control inputs, and it continued to descend until it was less than 30 feet above the ground. By the time the pilot had regained full control of the aircraft, it was on a collision course with the roof of a large building. The left main and nosewheel were torn off, and sheets of roofing iron were left hanging from the right mainwheel and left wing. The pilot was able to maintain control and manoeuvred the aircraft for a landing on the flight strip, using a windrow on the side of the strip to support the fuselage in place of the missing mainwheel. The pilot's description of the sequence of events and the lack of suitable terrain which could cause a significant down-draft, indicated that the aircraft probably stalled whilst the pilot was concentrating on the airstrip inspection. The pilot's inexperience caused him to mis-identify the cause of the "sink" and he used an incorrect stall recovery technique.

Significant Factors:

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

1. Pilot relatively inexperienced.

2. Possible channelized attention as the pilot concentrated on the inspection.

3. The pilot probably failed to ensure that sufficient airspeed was maintained to prevent a stall.

4. Improper recovery actions.