Circumstances:

As part of their commercial pilot training scheme, the flying school sent five trainees supervised by two instructors, in two aircraft to further their experience by operating from a remote aerodrome. The two aircraft arrived at Longreach Aerodrome before noon on the day of the accident. The instructor in charge of the operation had apparently decided to take two trainees flying in the local area. The flight was authorised for radio navigation aid training. The aircraft was later seen over a period of time, flying at heights judged as 100 feet and lower over the flooded Thomson River. Later, some two kilometres north-west of the Thomson River, two stockmen saw the aircraft flying parallel to the Winton Road towards Longreach township when suddenly the wings separated from the fuselage which then crashed to the ground. The aircraft had flown into a subsidiary powerline strung across the main road. Two steel wires had struck the windscreen and had sliced both wings and centre support section away from the fuselage. The span of the wire struck was 239 metres. The point of impact was 8.2 metres above ground level and 67 metres from the main feeder powerline which parallels the far side of the main road. At the time of the accident, the wind was calm, the sky was clear of cloud, and the sun was directly behind the aircraft. Although the visibility was excellent, tests conducted exactly 24 hours after the accident revealed that the wires would not have been visible to the pilots in time to avoid a collision.

Significant Factors:

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

1. The pilots were engaged in an unnecessarily hazardous operation - low flying.

2. The pilots were unfamiliar with the local area.

3. The pilots did not see the subsidiary power line in time to take collision avoidance action.

Circumstances:

The pilot reported that shortly after take-off on the seventh parachuting flight for the day the left engine fuel low pressure warning light illuminated. Activation of the auxiliary pump did not rectify the problem and the engine stopped. Following completion of the left engine shutdown drills and an apparent inability to outclimb the rising terrain, the pilot elected to shut down the right engine and land in a paddock. Landing gear extension had just commenced when the aircraft impacted the ground. The aircraft ground looped to the left in the landing slide. As the parachuting operation involved climbing to 12000 feet, to enhance climb performance and minimise sortie time, minimum fuel was carried. The pilot and the operator considered that the regulations relating to fuel reserve requirements did not apply to parachuting operations. The planned fuel for the flight was therefore substantially less than statutory requirements. A complete fuel drain and quantity check revealed only 19.5 lbs (11 litres) of fuel remained in the left tank and 231 lbs (130 litres) in the right. The amount of fuel burned since the last refuel was 24 lbs (13.5 litres). The inspection of the aircraft fuel system revealed that the fuel quantity indication system was defective. The left outer fuel quantity sender unit was unserviceable and showed a reading on the left outer fuel gauge of 100 lbs and empty on the left inboard gauge when both the inboard and outboard fuel tanks were completely empty. The pilot was unaware of the significance of this fuel gauge indication anomaly. All fuel pumps were serviceable and both engines were found to be capable of operating throughout the design power range. The wind at the time was south-easterly at 10 knots gusting to 15 knots. The into-wind take-off was over rising terrain with a 5-7 knot crosswind from the left. It is considered that during the initial climb phase of the flight insufficient fuel remained to cover the left fuel pumps and outlet ports, effectively starving the left engine of fuel. No reason could be found for the inability of the aircraft to outclimb the terrain on the remaining engine. Performance tests revealed that, at worst, the aircraft would have been capable of maintaining level flight following the failure of the left engine. It is probable that the visual illusion caused by the rising ground on the initial climb track induced the pilot to assume that the aircraft was descending.

Significant Factors:

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

1. The pilot's knowledge of the aircraft systems was inadequate.

2. The fuel quantity in the left fuel tanks was inadequate to ensure continued operation of the left engine.

3. The left engine failed due to fuel starvation.

4. It is probable that a visual illusion caused the pilot to believe the aircraft was descending, and consequently, to abandon the take-off.

The pilot was assisting stockmen to move cattle through a gate when one animal broke away. While manoeuvring to cut off the escaping animal, the helicopter struck a single wire power line which traversed the area. The power line was approximately 11 metres above ground level at the point where the collision occurred. The impact caused the main rotor to sever the tailboom and the helicopter fell to the ground and caught fire. The pilot was aware of the location of the power line and had been working in close proximity to it prior to the accident. This occurrence was not the subject of an on-site investigation. The information was provided by witnesses to the accident.

The pilot was operating the aircraft from the top of a gently sloping ridge in light and variable wind conditions. He lifted the aircraft into a hover one metre above ground level and began to accelerate forward. At about translational lift speed, the helicopter lost height and the tail rotor struck the ground. The pilot was able to land the aircraft straight ahead. Damage was sustained to the tail rotor drive, gearbox, and blades. The pilot had started work at 0445 hours on the day of the accident. He had flown 4.5 hours and had sprayed five chemical loads prior to the accident. This was the first concentrated period of flying he had undertaken in more than three weeks. Also, it was his first early morning start in that time. Both these aspects could have led to the pilot suffering a degree of transient fatigue. This might have been sufficient to cause a slight degradation in his performance sufficient for him not to compensate fully for the nose-up pitch as the helicopter passed through translational lift. This accident was not the subject of an on-site investigation.

Circumstances:

The helicopter was flying between two and three hundred feet above ground level when the pilot noticed severe oscillations of the rotor system, followed by engine stoppage a short time later. During the subsequent forced landing, the right skid contacted the ground at a significant forward speed and the helicopter rolled on to its right side. Examination of the rotor system indicated no apparent faults or failures prior to the accident. Fuel was drained from the fuel tank and the two carburettors (three points). The fuel tank and left carburettor showed clean fuel but the right carburettor contained a small but significant quantity of dirty water and solid debris. The fuel was also discoloured to a grey tone. The quantity of water was sufficient to cause engine rough running (which would induce rotor system oscillation) and engine stoppage. The pilot reported that he had conducted fuel checks before the flight from two drain points, one for the main fuel tank and one for the carburettors, both accessible from the left side of the helicopter. He was not aware that each carburettor had its own drain valve and that there was a total of three drain points.

Significant Factors:

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

1. The pilot was not aware of all the fuel drain points on the helicopter.

2. The engine failed due to water in a carburettor.

3. The pilot misjudged height and speed during the forced landing.

The pilot was undergoing a routine currency check with a flying instructor. As part of the check the pilot was asked to carry out a hover taxiing autorotation. The power was reduced to flight idle with the aircraft about 5 feet above ground level and moving forward at taxiing speed. The pilot carried out what was considered to be a normal landing, however, shortly after touchdown a loud bang was heard and the tail rotor and stabiliser were seen to land in front of the aircraft. The tailboom had been severed by the mainrotor during the landing. Indentations left by the skids in the soft ground indicated that the aircraft moved forward about 4 metres after initial ground contact. The main rotor was found to have an excessive static droop angle which reduced main rotor tip clearance from the tailboom by approximately 75 millimetres. This, in combination with attitude changes during the touchdown on the soft surface, rotor tilt and reduced rotor RPM, was contributory to the development of the accident.

A Distress Phase was declared by the Brisbane Senior Operations Controller when an Emergency Locator Beacon (ELB) signal was received by an overflying aircraft, in the Tiaro area, at 2242 hours EST on 31 May 1989. A search the following morning located VH-KAU. The pilot of VH-KAU stated that during a spray run, the engine failed completely when the helicopter was about 5 to 8 feet above ground level. During the subsequent autorotation onto the hillside the mainrotor contacted the tailboom. The pilot stated that he had subsequently drained the fuel system and found evidence of water contamination in the fuel. The engine was being operated on diesoline which was not a recommended fuel. The main rotor head showed evidence of a large pre-existing crack near the hub, and this item is subject to further investigation.

Circumstances:

The pilot flew alongside a vehicle travelling along a gravel road. The two occupants of the vehicle knew the pilot well and they were not surprised to see the aircraft. The aircraft was then flown across the road in front of the vehicle at an approximate height of 250 feet. Whilst continuing their progress along the road, the occupants observed the aircraft perform a "wing over" manoeuvre. The aircraft failed to recover from the resultant steep dive, striking the ground at approximately 65 degrees nose down. The two occupants of the vehicle extracted the pilot from the crushed cabin. Detailed examination of the wreckage failed to reveal any abnormalities.

Significant Factors:

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

1. The pilot performed an aerobatic manoeuvre at a low height.

2. In all probability, the pilot inadvertently flew the aircraft into a high-speed aerodynamic stall from which he was unable to recover in the height available.

Circumstances:

Approximately 30 minutes into the flight, the pilot realised that the aircraft performance was less than expected. The pilot and passenger then observed the landing gear had not fully retracted and was in a trailing position. Upon arrival at the destination, several unsuccessful recycles were attempted and low-level passes made for inspection purposes. Further unsuccessful attempts were made to extend and/or retract the landing gear. The aircraft made an approach with the landing gear trailing. During the landing flare, the landing gear folded into the retract positions and the aircraft settled firmly onto the grass flight strip. The investigation concluded that a metal saddle supporting the landing gear hydraulic lines had worn loose. A section of that line had then become chafed from contacting the main landing gear assembly during extension/retraction cycles. Eventually the line fractured, resulting in loss of hydraulic fluid. Subsequent attempts to recycle the landing gear depleted the hydraulic reservoir, leaving the landing gear in the trailing position.

Significant Factors:

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

1. Hydraulic line saddle became loose in service.

2. Operation of the landing gear subsequently chafed the hydraulic circuit.

3. The landing gear was unable to be extended or retracted following failure of the landing gear hydraulic circuit.

The pilot was reported to be conducting the third of a series of solo circuits. Approach and roundout were normal and the pilot intended to wheel the aircraft on. The aircraft bounced twice so the pilot applied full power and raised the nose in order to go around. The left wing stalled and the aircraft turned left rapidly. On the next touchdown the right landing gear was torn off and the propeller and fuselage pod were damaged.