While making a turn shortly after commencing to taxy at Brisbane, the captain thought the nosewheel steering' felt slightly stiffer than usual. However, during the subsequent taxying and flapless take-off at Brisbane and the undercarriage extension at Maryborough there were no indications of any abnormality in either the nosewheel steering or undercarriage systems. An approach was made to land on Runway 17 at Maryborough with a light crosswind from the left. The aircraft touched down lightly on the main wheels about 1,200 feet fist the threshold. The nosewheel was lowered onto the runway and ground fine pitch was selected. Almost mediately severe nosewheel shimmy was noticed, accompanied by vibration and noise. The captain applied back pressure to the control column, in order to lighten the weight on the nosewheel, and ordered the first officer to carry out the impact drill. The severe vibration continued, and then, at 3,100 feet beyond the threshold, the downlock mounting lug on the nose undercarriage assembly failed allowing the assembly to pivot rearwards beyond its normal "DOWN" position. The captain applied the brakes as the aircraft continued rolling with the nosewheel pivot bracket and wheel lever fork-end skidding along the runway surface. The aircraft came to a halt 550 feet short of the southern end of the runway. Investigation showed that the nosewheel tyre was in a substantially deflated condition at touchdown and that the tube subsequently became mutilated and bunched in one section of the tyre resulting in an unbalanced nosewheel condition which generated fore and aft loads which were at or near the natural frequency of the nose undercarriage assembly.

Following a signal from the cabin attendant that all was ready for take-off, the pilot applied power and lifted the helicopter Into hover. After a momentary check of power and trim the pilot began to move the aircraft forward along the line of the taxlway towards the runway. At a height of less than 10 feet and with a forward speed of some 5 knots the aircraft engine coughed and lost power. The pilot noticed a drop and fluctuation In engine fuel pressure and the fuel booster pump low pressure warning light Illuminated. He reduced power and landed and as the aircraft touched and rolled forward, ground resonance commenced. The pilot endeavoured to lift the helicopter back Into the air In order to terminate the ground resonance, but this was- unsuccessful owing to the lack of engine power. The severe rocking motion, as ground resonance developed, bounced the aircraft to the left and the pilot then applied the rotor brake. The main rotor blades struck the ground, the undercarriage failed and the helicopter came to rest having rotated more than 180 degrees from Its original heading. The pilot carried out an engine shut down check and he vacated the aircraft through the right hand cockpit window. All the other occupants vacated the aircraft through the main cabin door under the direction of the cabin attendant. Fuel was seen to be pouring from the lower forward section of the fuselage and this Ignited whilst the passengers were still evacuating the cabin, forcing the last persons out to leap through the flames.

The landing strip at Wongrabry Station is 2, 600 feet long and is aligned in approximately an east-west direction. The station homestead is near the eastern end. The aircraft was fitted with dual controls and it is not known which pilot was controlling the aircraft. The aircraft took off into the west and made a partial circuit to the south of the airstrip, approached the strip from the east, passed over the homestead at a height estimated at between 600 and 800 feet and then new parallel with and above the strip. At a point approximately above the western end of the strip the aircraft completed a controlled roll to the left through 360 degrees, recovered and continued westward in level flight. About 1 1/2 miles beyond the strip it zoomed sharply upward into a stall turn type manoeuvre to the left and entered into a steep 70 degree dive. As the dive progressed the speed increased to about 200 knots and the dive angle progressively decreased. When the aircraft was about 200 feet above the ground it had attained a nearly level attitude but was still descending. It passed out of sight of eye witnesses and struck a tree and then the ground.

On the morning of the accident the pilot flew the aircraft from Glenrelgh Station to Hughenden, a distance of 63 nautical miles and arrived at approximately 1000 hours. During the course of the day he consumed a quantity of alcohol. The pilot, who was not qualified for instrument flight, planned to return to Glenreigh that evening but, although last light at Glenrelgh was at 1844 hours, he did not depart Hughenden until 1810 hours and made a planned landing at Peronne Station some 10 minutes later. At about 1825 hours the pilot departed on the 43 nautical mile flight to Glenreigh Station and arrived over the airstrip at about the end of daylight. The aircraft was seen to circle over the strip and make an approach Into the south east with the landing lights Illuminated. A vehicle had been positioned at the side of the north western end of the strip so as to Illuminate the landing area with Its headlights. When the aircraft was almost at the touch down point at the north western end of the strip, the engine power increased and the aircraft climbed away. It made a left hand turn as though to continue around and make another approach. However, when flying above the almost featureless terrain In a position some 2700 feet to the north east of the strip, the aircraft entered a steep dive, crashed to the ground and immediately caught fire. The pilot had been undergoing medical treatment involving tranquilislng and sedative drugs and the possibility exists that this medication interacted with the alcohol consumed to further impair the ability of the pilot.

While cruising in level flight the engine, without warning, commenced to vibrate severely. Engine instrumentation remained normal and a magneto check was satisfactory. The vibration increased rapidly to such a degree that the pilot had no alternative but to close the throttle fully and carry out a forced landing. The aircraft was over very rough terrain and the only field available was 1,580 feet in length with trees to 70 feet high at one end and to 20 feet high at the other. The approach was made towards the taller timber, with the wheels down and half flap in a cross wind of about 10 knots from the left. After touching down the pilot realized that the aircraft would overrun the available area and he immediately initiated a turn to the right. Because of the speed and the rough surface, the aircraft skidded sideways and the undercarriage collapsed. The aircraft performance chart indicates that an actual distance of 1,740 feet is required to stop the aircraft from a height of 50 feet when using full flap under the conditions existing at the time of the landing.

The pilot approached Gladstone from the north-west and radioed a position report at 10 miles. Joining the circuit he noticed another aircraft apparently making a touch-and-go landing on runway 28 and was in radio contact with it. As there was nil wind and new paintwork on the eastern end of the runway he elected to land on runway 10. When on the downwind leg he saw a second aircraft at the taxiway holding-point and, as a warning to it, made a base leg radio call. During the final approach and at a height of approximately 15 feet the second aircraft entered the runway so the pilot grabbed his microphone in an effort to give a warning but lost control of his aircraft which landed heavily on its nosewheel; it then proposed several times and the propeller struck the runway twice.

When at a position about six miles south of Maryborough and at a height of about 3, 000 feet, the aircraft suffered a complete loss of engine power. The pilot chose to force land on the local golfcourse but, to do this, it was necessary to make a down wind approach over a power line and trees. The pilot forced the aircraft on to the ground immediately after clearing the obstacles so as to obtain braking effect as soon as possible since there were houses at the far end of the landing area. The nosewheel struck a grass bank at the point of touchdown and the nosewheel and fork broke off. The aircraft bounced and then slid on the collapsed nose strut and main wheels coming to rest after a swing to the left of 80 degrees. The fatigue failure of the studs and through bolts was compatible with lack of adequate pre-load applied by the respective nuts.

The pilot departed an airstrip close to the town of Proserpine, In good weather, to fly to his property at Kelsey Creek. He overflew the unfenced and partially completed landing area to Inspect It for obstructions and ascertained there was no wind. Because the sun was still low In the east, the pilot made a precautionary approach and touchdown Into the south-west. When the wheels were firmly on the ground, a kangaroo bounded across the landing path from the adjacent grass area and was struck by the nosewheel assembly which was damaged and slowly folded rearward. The aircraft then skidded on Its nose for 148 feet before turning over.

The pilot was attempting a short landing from a powered approach to a property airstrip in a south-easterly wind of ten knots. He selected full flap (35 degrees) and made an approach at 50 knots and, as he passed over outbuildings, he looked down to confirm he had cleared them. After crossing the strip boundary he looked ahead and closed the throttle to land. The aircraft immediately increased its rate of descent and the pilot applied power but was unable to prevent a heavy three point landing. The aircraft bounced and was re-landed with engine assistance. During the landing roll, the pilot noticed a right wing-down attitude, and, after turning and while taxi -ing, the starboard undercarriage leg collapsed.

The pilot had been informed by his Chief Pilot that the strip was 3000 feet long when In fact its length was 2, 300 feet. The aircraft weight and ambient conditions were such that the aircraft required the full strip length for take-off if using 20 degrees of flap, and 2, 650 feet for take-off if Hap was not used.

The pilot began a rolling take-off without flap and, when committed to continuing the take-off, he selected eight degrees of flap. He lifted the aircraft off the ground just before reaching a fence 200 feet beyond the end of the strip. The undercarriage struck the fence and the pilot abandoned the take-off and landed In the adjacent paddock The aircraft entered a shallow swamp, breaking off the nosewheel fork before coming to rest.