The aircraft was cruising at 10,000 feet at night, when the passenger noticed the manifold pressure reducing. The engine rpm also dropped and the pilot changed fuel tanks, switched on the fuel boost pumps and moved the throttle and pitch controls to the fully forward positions. At about the same time the manifold pressure and engine rpm readings reportedly dropped to zero. The aircraft was set up in a glide and despite several attempts engine power could not be restored. The pilot tracked the aircraft towards a town and descended over the town before taking up a westerly heading in preparation for landing. At about 20 feet above the ground the aircraft struck a tree and then landed heavily on a steep bank. An inspection of the engine found that the crankshaft had failed due to a fatigue fracture initiated from a manufacturing fault. An Airworthiness Directive regarding inspections of crankshafts in this type of engine has since been introduced.

At a height of about 80 feet above ground level with little forward speed, the helicopter suffered a complete power loss. During the subsequent autorotational descent the main rotor struck trees, and the right skid was torn off on impact with the ground. Investigation revealed that two connecting rods had become detached from the crankshaft, and the engine had seized. It was likely that a previous overspeeding of the engine had stretched the big end bolts. This led to a loss of torque on the nuts retaining the bolts, which finally suffered overload failures.

Thirteen minutes after departing Brisbane the crew was instructed to "contact Brisbane Control now on 127.2" (the next VHF en route radio frequency). This message was received at 1023 E.S.T. and acknowledged. At 1039 hours, Brisbane Flight Service received a radio check call from the aircraft on HF. However, despite numerous calls from Brisbane, Sydney, and Melbourne Airways Operations units, nothing further was heard from the aircraft on VHF until 1144 hours when the crew contacted Sydney Control requesting transfer instructions to Melbourne. The aircraft's progress was monitored on radar throughout the flight and, as it appeared to behaving normally, no fears were held for its safety. In his report, the Captain stated that both VHF radios had been inadvertently selected to 127.3 MHz instead of 127.2 MHz. Both pilots had heard aircraft communicating on this frequency, which is a Melbourne-Sydney route frequency, and believed communications were normal. Neither pilot could recall transfer instructions being issued, or calling Brisbane Control on frequency transfer. Examination of taped air/ground communications did not reveal any record of the crew having checked-in on frequency 127.3 MHz following transfer, as required by standard procedures.

The aircraft was on climb towing a glider when the pilot saw smoke and flames around the left rudder pedal area. The glider was released and the pilot landed the aircraft in a paddock. He abandoned the aircraft before it was destroyed by fire. Because of the severity of damage the cause of the fire could not be determined. It was established that the fire melted fuel lines in the cockpit walls and fuel released then fed the fire which completely gutted the aircraft.

The pilot had flown from Adelaide to Bacchus Marsh, on 25 July 1980, and had left the aircraft there while he attended to private matters. On his return during the afternoon of 1 August he discovered that there was no fuel available, and elected to fly to Essendon to refuel and to obtain a pre-flight briefing. It had been the pilot's intention to proceed as far as Horsham and remain overnight before continuing, however the weather forecast was satisfactory and he decided to plan a Night VMC flight to Adelaide. The pilot noted on the plan that the lowest safe altitude on the initial leg to Yarrowee was 3500 feet above mean sea level (amsl), and was 4800 feet amsl between Yarrowee and Mt William. Planned cruising altitudes were below 4000 feet amsl to Yarrowee, thence below 5000 feet amsl. About 25 minutes after DEPARTURE the pilot was advised that the weather at Adelaide was deteriorating and he elected to divert and land at Horsham. Amended flight details were passed, indicating that the aircraft would proceed to Horsham from over Mt William, cruising below 5000 feet amsl. At 2049 Melbourne Flight Service contacted the pilot and requested an estimated time of arrival for the Mt William position. The pilot replied that his revised time for the position was 2051. This was the last transmission received from the aircraft. At about 2050 witnesses noted an intense fire near the summit of Mt William. The following day it was established that the aircraft had collided with the almost vertical face of the mountain, some 400 feet below the summit, while apparently in cruising flight at about 3400 feet amsl and on the track from Yarrowee. The wreckage had then fallen about 200 feet to sloping ground and had been consumed by an intense post-impact fire. The weather at the time of the accident was reported as fine, with good visibility. Although the winds were stronger than forecast, it was considered that there was no significant turbulence or downdrafts in the area. The examination of the wreckage was hampered by the extent of the damage, however no evidence was found to indicate any pre-impact defect which might have contributed to the development of the accident. The reason the pilot was flying the aircraft more than 1000 feet below the lowest safe altitude for the route sector could not be determined.

Prior to the flight the pilot was given details of the paddock in which the glider was located, by the glider pilot. This information included reference to power lines on the western side. An inspection run into the west was performed at 300 feet agl and as a run at a low height towards the east was commenced the landing gear struck a power line suspended 9 metres above the ground. The aircraft struck the ground in a vertical nose down attitude and came to rest inverted. The power line ran obliquely across the paddock from a line of poles paralleling a railway track. There were no supporting poles in the paddock to alert the pilot as to the whereabouts of a power line and he assumed that those running next to the railway were the ones mentioned in the briefing.

The pilot intended landing in a paddock to inspect the results of recent spraying. He was aware of a power line well beyond the intended landing area. Sheep obstructed all of the paddock but the pilot hesitated in going round. Having temporarily forgotten about the power line, he then saw it too late to climb over and the top of the fin was severed as the aircraft was flown under the wire. The impact jammed the rudder, however the pilot was able to carry out a safe landing in the adjoining paddock.

Circumstances:

The pilot reported that he had flown one practice crosswind circuit and landing and was taking off for a second circuit when the left engine failed. The aircraft was about 20 feet off the ground, and the landing gear was still down. The pilot feathered the left propeller but then considered that he could still land safely straight ahead on the remaining runway. He selected full flap, but they did not extend because hydraulic pressure was not available as the failed left engine was not driving the hydraulic pump. The aircraft floated for some time and then touched down. The pilot applied full braking but was not able to prevent the aircraft from over-running the end of the strip and entering an area of button grass. The aircraft came to rest with the nose gear collapsed. A fire, which destroyed most of the aircraft, broke out in the area of the left engine. A detailed examination of the left engine did not disclose the reason for the power loss.

Circumstances:

The pilot reported that after conducting a local joy flight, he had intended to do one touch and go landing, a circuit, and a full stop landing. He stated that just as he was commencing his prelanding checks, he became concerned that one of his passengers, a small child, may have been feeling ill. He then turned around to see if the child was all right, and as a result, forgot to lower the gear. He stated that he did not realise his mistake until he heard the sound of the flaps scraping on the runway.

During the takeoff roll the pilot noted a loss of aircraft performance, but considered that there was insufficient strip length remaining to safely stop the aircraft. Shortly after becoming airborne the tail assembly struck the wooden top railing of a bridge. The left wing tip struck a dead tree 65 metres further on, the aircraft slewed to the left, touched down and came to rest with the engine and landing gear torn from the fuselage. No fault could be found with the aircraft systems which may have contributed to the reported loss of performance. The take-off, on a oneway strip, was conducted with a slight tailwind component and the estimated take-off weight slightly exceeded the climb weight limit specified in the aircraft P chart. The pilot's technique to assist in getting the aircraft airborne was to progressively select full flap during take-off. On this occasion the use of full flap apparently degraded the climb performance of the aircraft to such an extent that it collided with the bridge.