Loss of control

Prior to commencing a charter flight from Launceston to Flinders Island the pilot made a visual check of the fuel tanks and assessed that they were full. He was not aware that since the aircraft had been refuelled it had made a flight of 1 hour 45 minutes duration. On the return flight, approaching Launceston, the pilot was given landing instructions and when the aircraft was established on a visual descent, the engine failed. As he was only 1, 000 feet above unsuitable terrain, he turned towards the only suitable field in the area and attempted to restart the engine. Being unable to do so the pilot gave his attention to the forced landing and requested a wind velocity from Launceston Tower. Because of his position and altitude he elected to land downwind in the 15 knot wind, in the field previously selected. The aircraft touched down and rolled for a considerable distance before the pilot began a ground loop to avoid striking a fence across his path. This manoeuvre was only partly successful because of the damp grass and the aircraft struck a fence post and damaged the tail plane and rear fuselage.

The pilot had completed three aerial seeding flights over areas In timbered and mountainous terrain In a light northerly wind. On the fourth flight he was making runs down a slope from north-east to south-west and, after each run, was repositioning his aircraft at the top of the slope by flying a right hand circuit. At the end of one run and with only a small area to complete, the pilot decided to make a left turn and a finishing run up the slope and to leave the area by turning left again. During the final run he became aware there was Insufficient space to permit the Intended manoeuvre so he turned right toward a lower spur line but realised he was unlikely to clear this. The pilot operated the dump lever, the aircraft settled Into the trees with full power applied and fell to the ground, coming to rest Inverted.

During the day the pilot, who was inexperienced in agricultural operations, had completed the spreading of superphosphate while under the supervision of a Class 1 agricultural pilot. The strip used, though adequate in length, was substantially below the prescribed minimum in width, it was bordered by rough, rutted ground and targe rocks and the transverse gradient was in excess of the specified maximum. In the late afternoon the pilot returned to the strip to load some equipment. The wind was calm and shortly after making a normal landing the aircraft diverged approximately 12 feet to the right of the strip centre line. Due to the rough ground and downslope the pilot was unable to regain the central strip and the main wheels struck some large rocks tipping the aircraft on to its nose.

Prior to landing on a strip which is aligned in a southerly direction, the pilot estimated that he would be subject to a cross wind of from 10 to 12 knots from the left. However, he was not aware that the topography adjacent to the strip threshold could considerably influence the ambient wind and, during the landing flare -out, the aircraft encountered a strong wind gust from the left. On touchdown the aircraft commenced to turn to the left and, although the pilot took remedial action, he was unable to maintain directional control. In the latter stages of the landing run, the aircraft swung further into wind and the nose landing gear strut bent.

The aircraft was engaged in superphosphate spreading in hilly country and, after commencing operations at approximately 1400 hours, had completed seven sorties. The runs were made in predominantly easterly and westerly directions and the eastern end was close to the main north-south ridge of the Brawboy Range. The aircraft had been observed turning at the eastern end of the runs by proceeding out through gaps in the ridge and then returning across the crest of the range to spread in a westerly direction. At the termination of the last completed run to the east the aircraft was seen to pull up high and turn inside the face of the ridge before descending and disappearing from the view of the witness. Smoke was seen to rise from the area immediately and the burning wreckage was sighted shortly afterwards by searching aircraft.

The pilot and an assistant had rigged a launching device which utilized a bungee assembly of motor tyre tubes, and a vehicle and cable to launch a glider over the slope of Big Talbingo Mountain. It was intended that when the glider was released, sustained acceleration was to be obtained by the vehicle and cable moving away from the glider. The weather conditions were favourable with the glider facing into a wind of 10-15 knots. The assistant positioned the vehicle such that the slack in the system was taken up before he spoke to the pilot who was now in the cockpit and who briefed him again on the required procedure. The vehicle was driven away, stretching the bungee assembly, but at a speed too slow to sustain acceleration of the glider after automatic release. The pilot was aware of the situation, but was committed to the launch and when further movement of the vehicle automatically released the cable retaining the glider, the launch commenced and the glider moved forward without continuing to accelerate and rolled over the edge of the clearing. The left wing dropped and the aircraft continued to sink until it struck the rocky cliff face. The launching system, modified from one used previously by the pilot, was untried and the procedures to be used had not been practised.

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.

When the aircraft arrived over Hughenden it descended to a height of about 400 feet over houses on the southern and north-eastern areas of the town, then climbed slightly and flew at a low height across the town towards the golf course. The aircraft, on two occasions, flew at a height of about 300 feet over the golf course, in the vicinity of the club house, then climbed, circled to the left and descended to a very low height over a group of people who were playing golf. The aircraft then climbed steeply to approximately 200 feet at which height the pilot apparently lost control of the aircraft and it stalled, yawed sharply and dived to the ground. The Initial impact was taken on the nose and starboard main wheel and the aircraft skidded for a distance of 169 feet before coming to rest.