Circumstances:

The pilot reported that he was positioning for a pickup of passengers, and he had completed a visual circuit and approach to the strip. He achieved a gentle touchdown within 100 metres of the threshold of the 1065 metre strip on both main wheels. Coincident with lowering the nosewheel onto the strip, the pilot reported feeling the aircraft lurch which he first took to be symptomatic of a flat tyre on the left main gear. He had no trouble maintaining directional control. A little later, the left wing dropped further, and the gear warning horn sounded. The pilot was able to keep the aircraft within the defined width of the strip and, on coming to rest, he shut down the aircraft before egressing. A post flight inspection by the pilot showed that the left main gear oleo leg had swung rearwards and the lower surface of the flaps had been dented by the tyre. The reduced ground clearance had allowed the left propeller to strike the ground, but the left main gear doors were out of contact with the ground. A detailed inspection of the main gear components showed that the left main gear drag link centre bolt had failed in fatigue. Furthermore, all the landing gear components showed signs of wear beyond tolerances, and this condition was evident of inadequate maintenance and inspection.

Significant Factors:

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

1. Fatigue failure of the left main gear drag link centre bolt.

2. Probable inadequate maintenance and inspection. This accident was not the subject of an on-scene investigation.

The pilot reported the following The right main landing gear collapsed, soon after touch down at Maggieville Station airstrip, at the completion of a two hour flight from Massacre Inlet. The aircraft had been configured for a short field landing, however, it had floated for a short distance along the airstrip before the main wheels touched down. As a result the pilot applied "full braking" as soon as the aircraft had settled on to the runway. At the same instant that the brakes were applied the right main landing gear folded backwards and collapsed. Investigation revealed that two of the three bolts which support the right main landing gear (including the main locating bolt) had sheared off, and the cast sections of both channel supports had been damaged. The pilot could find no evidence on the runway of an obstruction or pothole and has no recollection of any previous hard landings or wheel contacts, which might explain the damage. However, he did report that two of the right main wheel hub bolts, had failed and were replaced approximately one week prior to this accident. After carrying out temporary repairs, at Maggieville Station, the aircraft was flown to an approved maintenance facility in Mount Isa to have the right landing gear replaced.

The chief engineer, a Licenced Aircraft Maintenance Engineer (LAME), at the maintenance facility in Mount Isa, inspected the damaged section of the landing gear. He reported that both halves of the right main wheel hub had been damaged in a manner which indicated impact with a large object. Examination of the remainder of the landing gear supported this premise. Two of the three landing gear attaching bolts, had sheared off as a result of excessive side loads, and the remaining bolt was bent. Damage to the channel support was caused by the shearing action of the main landing gear exiting the fuselage attachment recess. The LAME stated that there was no evidence of corrosion, or any pre-existing cracks, found on any of the damaged components. The failure was totally consistent with an overload failure.

The investigation did not determine conclusively when the damage to the landing gear was sustained, but it may have been the reason the two wheel hub bolts had to be replaced the previous week.

The aircraft was cruising at 9500 feet when the oil filter adaptor became detached from the engine, causing complete loss of oil pressure. As a result the number two big end failed and the number two connecting rod punctured the crankcase. During the ensuing forced landing, on a road, the pilot was unable to fully manually lower the landing gear. After touchdown the right main gear leg collapsed, causing the aircraft to strike a dirt bank. The oil filter adaptor thread had been damaged by overtightening and this allowed the adaptor to detach from the housing on the oil pump casing. Following the failure of the engine it became necessary to lower the landing gear by using the emergency system. Hydraulic power to lower the gear is normally provided by the engine driven hydraulic pump. It was determined that the pilot was unable to fully extend the gear with the emergency gear extension handle as the handle had apparently inadvertently been moved slightly inward. Any inward movement of the handle jams the pump action making the handle difficult to move thus giving the impression that the gear is fully extended.

Circumstances:

The helicopter was engaged in cattle mustering operations. Whilst in level flight at an altitude of 200 feet, the pilot heard a loud noise and felt severe vibration from the engine, which subsequently failed. Following autorotation to ground impact, the aircraft rolled onto its side. The semi-conscious pilot was assisted from the wreckage by the passenger who had evacuated the cockpit unassisted. Strip examination revealed that the engine had failed due to broken conrod bolts and a separated conrod big-end cap from the No. 4 cylinder conrod assembly. This had resulted in internal mechanical damage sufficient to stop the engine.

Significant Factors:

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

1. Conrod bolt failure.

2. Loss of control during the landing. This accident was not the subject of an on-scene investigation.

The helicopter was lifting an industrial straddle platform from the top of a large, 300 foot high, cooling tower at an electric power station. As the helicopter took up the load, the sling-rope snagged on a small lug on the right landing gear skid. The 420 kilogram load, hanging from the right skid, caused the helicopter to bank rapidly to the right. During this rapid bank, one end of a 2 metre long plastic pipe, held by the crewman at the right rear doorway, contacted 3 of the main rotor blades. Within less than 5 seconds the rope unsnagged from the skid with a sudden jolt as the load positioned itself at the full extension of the rope beneath the cargo hook. Simultaneously the pilot regained a level attitude but found that the helicopter was already descending slowly, under control, within the approximately 30 metre wide opening of the top of the cooling tower. Because the pilot feared that the "jolt" had been possible damage sustained by the helicopter, he continued the descent gently towards the inside base of the cooling tower. A few metres above the base, the pilot jettisoned the load which subsequently damaged the inside of the tower. After jettisoning the load, the pilot landed the helicopter lightly on its skids inside the tower. The crewman got out and inspected the helicopter as best he could as the pilot kept the engine running. As no damage was seen the pilot carefully flew the helicopter out of the tower and landed nearby as the crewman proceeded out on foot. There was nowhere inside the tower for the helicopter to safely shut down. The sling rope had been lightly attached to the skid before the flight by availing of a loop in the rope and one wrap of adhesive tape. The intention of lightly attaching the rope to the skid was to avoid the possibility of the rope being accidently caught on the rear protrusion of the skid during the lift. During the hook-up of the load, the helicopter encountered some turbulence which caused the helicopter to move forward of the desired hover position. During this forward movement, the thick rope slid aft along the right skid and a core strand of the rope snagged on a small lug which meant that the pilot could not jettison the load. At the time, the crewman was restrained at the right rear doorway. His task was to give manoeuvring directions to the pilot and to attach a hook on the far end of the sling rope to the load with a length of plastic pipe. The 420 kilogram load hanging from the right skid placed the helicopter outside the lateral centre of gravity limits for pilot control. Just as the helicopter banked rapidly right, the straddle platform lifted clear of the tower long enough for the helicopter, with the load still dangling from the right skid, to move into the stack opening where a slow descent commenced in a slight downdraft. During the preflight planning, the pilot and the crewman did not consider it possible for the thick rope to snag on either of the 2 small lugs which are designed for the attachment of ground handling wheels. The use of the adhesive tape held the rope close enough to the top surface of the skid for the rope to come into close proximity with the lugs.

Circumstances:

The purpose of the flight was to revalidate the Night VFR rating of the pilot under check. The pilots intended to conduct several circuits and then carry out a short navigation flight. The flight apparently proceeded without incident during the startup, taxi, and take-off from runway 12. The tower controller reported that he then saw the aircraft initiate a turn as if to fly a right circuit, contrary to previously acknowledged directions for left circuits. When this was queried by the tower, the crew confirmed that they intended to carry out a left circuit, and the aircraft was then seen to turn left. This was the last sighting of the aircraft by the controller as he then transferred his attention to other aircraft. When the aircraft later failed to reply to calls from the tower, a SAR phase was declared and this later developed into a full scale search for the aircraft.

The wreckage was discovered some hours later. The direction of take-off had been to the south-east, away from any ground lights, and on a moonless night. This resulted in no natural horizon being available to the pilots. A partial electrical power failure in the city and surrounds of Alice Springs occurred prior to the aircraft taking off and a total blackout occurred after the time established for the crash. While the reduced area of the ground lights pattern was judged not to have contributed to pilot disorientation by a reduction in visual cues, this unusual phenomenon may have caused the diversion of attention of one or both pilots. However, no positive conclusions could be drawn. The subsequent investigation revealed that the aircraft had crashed with the pilot-under-check at the controls. It had passed through the top of a tree before striking the ground at high speed, in a left wing low configuration. The landing gear and flaps were retracted.

Ground impact had almost totally destroyed the forward fuselage and cockpit, and the aircraft came to rest inverted some 100 metres after ground contact. The engine had been dislodged and was found about 200 metres beyond the fuselage. Detailed airworthiness inspection failed to detect any fault or anomaly in the aircraft which could be considered to have contributed to the accident. The total night flying experience of the check pilot was some 37 hours, of which six hours had been flown in the last 90 days. However, he had successfully completed a Night VFR revalidation flight for another pilot twelve days prior to the accident and flown some two hours at night three days before the accident. The pilot-under-check had only 14 hours total night flying experience and had not flown at night for 25 months. The conclusion was drawn that loss of control of the aircraft occurred for undetermined reasons at an altitude that was insufficient to effect a recovery.

Significant Factors:

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

1. Both pilots had low levels of night flying experience.
2. There was no natural horizon available to the pilots.
3. For reasons undetermined, there was a loss of control of the aircraft at an altitude insufficient for recovery.

Circumstances:

On the flight to Bathurst Harbour immediately prior to the accident the pilot-in-command occupied the left pilot seat, and the co-pilot occupied the right pilot seat. Shortly after take-off on that flight the pilot-in-command handed over control of the aircraft to the co-pilot who was very experienced on tailwheel aircraft. The co-pilot landed the aircraft at Bathurst Harbour without any problem. After a short time sightseeing the party boarded the aircraft for DEPARTURE. The copilot was again handling the controls. Taxiing and the initial take-off run appeared normal but when the tail was raised the aircraft swung to the left. The take-off was discontinued but directional control was not regained. The aircraft left the strip and came to rest in a peat bog a short distance further on. After the accident, the co-pilot's rudder pedals were found to be in the stowed position which disconnects them from the rudder control system. It was not determined when the pedals were put in the stowed position, but it was determined that the co-pilot had not been briefed on the rudder pedal stow system.

Significant Factors:

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

1 Inadequate preflight inspection carried out.

2 The co-pilot was not briefed on the rudder pedal stow system.

3 Take-off was attempted with the rudder pedals stowed. 4 Loss of directional control on take-off.

Circumstances:

The aircraft was returning to Bankstown at the completion of a cargo charter flight. Take-off from runway 35 proceeded normally until the aircraft reached a height of about 90 feet when severe wind shear was encountered, resulting in a high rate of sink. The pilot was unable to prevent the aircraft from settling back onto the runway with the landing gear retracted. The prevailing conditions were conducive to the formation of mechanical turbulence in the lee of nearby mountains. At the time of the accident, it was reported there were large fluctuations in the wind velocity at Wollongong aerodrome.

Significant Factors:

The following factor was considered relevant to the development of the accident:

1. The aircraft encountered severe wind shear at a critical stage of the take off and lacked the performance to prevent a collision with ground.

The pilot who was flying the aircraft occupied the left seat. He was being endorsed on type and it was his second flight in the aircraft. After DEPARTURE from Bankstown the aircraft was flown via the training area to Camden where it was intended to conduct circuit training. On the second circuit, the landing gear was reported to have extended normally and an indication of three green lights obtained. During the ground roll, following a normal landing, and before the instructor called for the pilot to continue with the touch-and-go, the right wing began to settle as the right main gear retracted. The instructor took control and brought the aircraft to a halt on the runway. Both the left main and nose gear legs remained fully extended. He said that he selected the gear lever to the down position when the right wing commenced to drop. An examination revealed the right main gear jack upper attachment had detached. It indicated the down side of the jack was pressurised whilst there was weight on the wheel and the overcentre lock was not made. This is consistent with the landing gear having been momentarily selected up during the landing roll and then selected down again. No mechanical defects were discovered during repairs to the aircraft which might have resulted in inadvertent gear retraction. The instructor had briefed the pilot under going training that he, the instructor would raise the flaps during the ground roll on touch-and-go landings. The PA 23 aircraft has the flap selector on the left side of the throttle quadrant and the landing gear selector on the right side; the reverse layout of most light aircraft equipped with retractable gear.

The aircraft was cruising at 6500 feet; the mixture had been leaned and the engine was operating normally. The pilot then reported that the engine note changed although all engine indications were normal. Approximately five minutes later the engine coughed and spluttered and started to lose power. The loss of power was reported to be rhythmic in nature, a few seconds of power followed by a like period of loss of power. The pilot turned the aircraft towards the DEPARTURE point and completed trouble checks, but these checks did not rectify the malfunction. It became apparent that the DEPARTURE strip could not be reached so the pilot turned south to intercept a dirt road he knew was in the area. The dirt road was located and with the stall warning sounding he selected full flap and turned to line up with the road. During the turn the aircraft grazed the top of a seven metre high tree. The aircraft then stalled onto the road from a low height. The nosewheel collapsed and the aircraft nosed over onto its back. Since there was no suitable terrain for a forced landing within gliding distance an accident was inevitable. Despite extensive examination of the engine and its components, no defect that would have caused a partial or total engine failure was found.