The aircraft was cruising at 2000 feet above mean sea level, when the pilot observed an apparent engine failure. The pilot set the aircraft up for an autorotational approach. As the aircraft approached the ground, the pilot observed that the surface was not suitable for a run-on landing so he modified the approach, just prior to touchdown, so that the aircraft would land with zero residual forward speed. The touch-down was heavier than normal and the main rotor severed the tail boom. After landing the pilot observed that the engine was still running, but at a speed well below ground idle, and it had to be shut down manually. The engine lost power because the body of the power turbine governor failed as a result of high cycle, low stress fatigue cracking. The precise reason for the start of the fatigue crack could not be determined. However, it is likely that it was caused by the additional stress placed on the governor body when the vibration of an unrestrained servo pressure accumulator was transmitted to the body by the rigid stainless steel piping. The stress may have been aggravated by contact between the accumulator and an undetermined part of the aircraft.

As the aircraft was accelerating to the normal climbing speed after takeoff, the pilot lost elevator control. The nose continued to pitch up until the pilot closed the throttles. He then discovered that he could maintain limited pitch control by the judicious use of power. A successful gear-up forced landing was made, however, during the landing slide one wing was torn off after it struck a tree. An inspection of the elevator control system revealed that its control cable had been incorrectly engaged into the control column fork. While the locking pin was fitted correctly, it was rendered ineffective due to the incorrect fitment of the cable. Despite numerous maintenance inspections this error went undetected. Due to the location of the control column fork, the pilot would not have been expected to notice the unserviceability on his daily inspection.

On arrival at his destination the pilot is reported to have overflown a house near the strip before entering a steep climb to an altitude of about 300 feet. The aircraft was then observed to enter a steep left turn and dive into the ground. The pilot received head injuries in the accident and had only limited recall of the events of the day. However, it appears likely that the aircraft was stalled during the steep turn and entered a spiral/spin from which the pilot was apparently unable to recover. This accident was not the subject of an on-site investigation.

After completing a circuit, the aircraft was flown along the strip at an altitude of 50 feet. An airspeed of 50 knots was maintained with a low power setting. Towards the end of the strip the pilot attempted to apply climb power but the engine did not respond. The pilot selected a clear area straight ahead and landed the aircraft. During the landing roll the aircraft struck a tree stump which was hidden in the tall grass. The contact spring was missing from the distributor cap, which caused the output from the magneto to short circuit to ground and as a result of which the engine lost power.

The owner of the aircraft is reported to have worn a neck brace to assist with his recovery from a neck injury suffered some years ago. On the evening preceding the accident he had complained of feeling unwell. The next morning he rose at about 0600 hours and apparently prepared the aircraft for a flight to a neighbour's property. The wreckage of the aircraft was located about four kilometres north of the pilot's homestead at 0830 hours. The aircraft was found to have impacted the ground in an inverted attitude. Examination of the wreckage indicated that the aircraft had been constructed and maintained to a high standard and no defect could be found that may have contributed to the occurrence. The aircraft was fitted with a serviceable emergency parachute which had not been activated by the pilot. The actuating lever was readily accessible within the cockpit. Post mortem examination revealed that the pilot suffered from coronary artery disease. It was also reported that he had previously suffered several periods of total incapacitation. It is considered possible that he may suffered incapacitation in flight.

The aircraft had previously been flown to test a new propeller installation. Maintenance personnel then checked the propeller, after which the pilot taxied for a local flight. Shortly after take-off there was a sudden and complete loss of power. The pilot attempted a forced landing in a paddock, but the aircraft stalled at a low height and struck the ground heavily. The engine had failed when a small piece of felt in the carburettor blocked the flow through the fuel nozzle. The felt had evidently been in the carburettor since the previous disassembly of this unit. The pilot had only limited experience on the aircraft type, and had probably not monitored the airspeed during the latter stages of the forced landing.

Circumstances:

The pilot reported an uneventful flight and landing. After landing, while turning to the left off the main runway, the nosewheel entered a soft patch of earth and the nose landing gear collapsed. Both of the propellers, and the underside of the fuselage nose section were damaged. A subsequent check by maintenance personnel could find no evidence of a pre-existing fault in the nose landing gear assembly.

The pilot was called out at about 0400 hours local time for an urgent medical flight from Wynyard to Melbourne. This required positioning the aircraft from its base at Devonport to Wynyard. The take-off from Devonport was made in darkness with an overcast sky and light drizzle. The aircraft then apparently continued on the take-off heading at high power and low level until it struck the ground at high speed in a forest area 25 km south of Wynyard and 56 km from Devonport. The cause of the accident could not be determined but the possibility of pilot incapacitation could not be discounted.

On arrival at the destination, the pilot selected the landing gear down. Almost immediately afterwards, the radio frequency indicators faded, and a strong burning smell became evident. The pilot carried out a go-around, during which radio communications were lost and the burning smell became stronger. The pilot attempted to lower the gear with the emergency system, but found he was unable to move the manual extension handle. Under the circumstances, he elected to land as soon as possible. The aircraft touched down on the runway with the gear partially extended, and slid for about 200 metres before coming to rest. It was determined that the aircraft battery was almost completely discharged, but no other defect was found in the electrical system. It was possible that the pilot had not turned on the alternators before commencing the flight. When he selected the landing gear down, the gear motor had been subjected to excessive heat, and it had subsequently seized. The overheating was probably the result of high current draw under conditions of low battery capacity, causing reduced gear motor rpm. Because the motor and the emergency extension handle are on a common shaft, the pilot was unable to lower the gear manually.

Circumstances:

The pilot arrived in the area of his destination about sunset but was unable to locate the station airstrip. After a short search he found another strip with some buildings nearby and decided to land to ascertain his location. An aerial inspection of the strip was completed. However, the pilot reports that when the aircraft was on final approach, he noticed that what he had assumed was low scrub near the threshold was in fact 10 metres high trees. He adjusted the approach and touched down further down the strip than had been planned. The strip surface was loose, and maximum braking could not be applied. The aircraft overran the strip and collided with rocks and a dirt bank which resulted in the left main and nose landing gear legs collapsing. The strip was approximately 800 metres in length.