The flight proceeded normally after departure until about 1114 hours when the pilot noticed a decrease in engine RPM from 2500 to 2300. He opened the throttle but the RPM continued to decrease. As he was unable to restore power to the engine he turned the aircraft towards an open area, that had been overflown a couple of minutes earlier, and set the aircraft up in a glide. The area chosen was the only suitable area available for a landing. The pilot positioned the aircraft to join the downwind leg of the circuit and transmitted a "Mayday" call. As the aircraft was turned onto final approach the pilot spotted a six metre high tree near the intended touchdown point and manoeuvred the aircraft to avoid the tree. At this stage the flaps were selected fully down and the indicated airspeed was 75 knots. The aircraft subsequently floated for a considerable distance before touching down 453 metres after the first available touchdown point. The distance remaining to a fence at the end of the landing area was 309 metres. During the landing roll the right wingtip struck a small tree, as the pilot was attempting to manoeuvre the aircraft clear of an obstruction, and the aircraft was turned to the right. The right wing then struck a second tree which resulted in it being torn from the aircraft and the travel of the aircraft was halted. An inspection of the wreckage found that there had been an internal failure of one muffler which resulted in two of the four engine exhaust outlets being completely blocked.

Circumstances:

The student made a normal landing but as the aircraft slowed, the instructor noted the right wing was sinking and he assumed control of the aircraft. He held the wing up as long as he could and kept the aircraft straight without braking. The aircraft slowly veered to the right and came to rest off the sealed runway surface. The right hand landing gear wheel assembly had separated from the aircraft about thirteen metres after touchdown, with the result that the right hand flap, torque tube, aileron and stub of the landing gear cylinder were damaged by abrasion with the runway surface. The right hand landing gear strut had separated from the cylinder due to one of the two torque link securing lugs failing from fatigue, and the torque link retaining bolt failed due to overload. The main landing gear cylinder torque link lugs are subject to a visual inspection every 100 hours by aircraft maintenance engineers, but there is no existing requirement to inspect the strut torque link lugs.

Significant Factors:

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

1. The torque link lugs failed because of fatigue.

Recommendations:

It is recommended that the Civil Aviation Authority amend AD/PA-28/50 to incorporate dye penetrant inspection of the main landing gear torque link upper and lower mounting lugs.

Circumstances:

The aircraft was being winch launched on the pilot's second solo flight. Experienced observers on the ground reported that the take-off appeared normal, but soon after liftoff the aircraft adopted a steeper than normal nose up attitude. The pilot appeared to correct this to some degree but the aircraft continued to climb slightly steeper than normal. A video tape recording of the flight showed that, at a height of between four and five hundred feet above ground level, the tow cable broke. The nose attitude of the aircraft was quickly lowered to what appeared to be a near level flight attitude. A short time later, however, the glider rolled to the left and the nose dropped. The aircraft then spiralled through one and a half turns before impacting the ground. It would appear that, following the cable break, the pilot did not lower the nose sufficiently to maintain flying speed. As a result, the aircraft stalled and then entered a spin. The pilot had not experienced a tow cable break prior to this accident but had been instructed on the procedure to be adopted in the event of such an occurrence. The cable failure would probably have taken the pilot by surprise and this, coupled with his low experience level, could have contributed to the loss of control of the aircraft. These aspects could also have affected the pilot's ability to regain control of the aircraft.

Significant Factors:

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

1. The pilot's experience level was low.

2. The abnormally steep climb during the launch probably caused the tow cable to break.

3. The cable failure probably took the pilot by surprise.

4. The pilot lost control of the aircraft.

5. Control of the aircraft was not regained in the height available.

Recommendations:

During the investigation, it became apparent that cable failure training methods and standards varied across various gliding clubs. For example, the pilot involved in this accident had apparently received one simulated cable failure during launch. All his other training in this aspect was conducted in free flight at height under simulated launch conditions. At other clubs, students were exposed to simulated cable break situations at varying heights during the launch process including at least two separations below 400 feet for a landing straight ahead. Two exercises were also conducted above 400 feet which required a modified circuit to be flown. The considered advantage in these exercises is that the students were assisted in overcoming any reluctance in lowering the nose of the aircraft at realistic cable break heights. The Gliding Federation of Australia (GFA) Instructor's Handbook page 7-21 states that "simulated launch failures should be carried out at various stages of the launch until the pupil has demonstrated failure (competence?) at any stage of the launch". This statement is somewhat vague and perhaps leaves too much to individual instructor preference in what is a critical area of pre-solo training. The recommendation is made that the GFA revise the GFA Instructor's Handbook to define more clearly the type and number of cable failure simulations which should be conducted and the minimum standard that should be attained.

The aircraft departed Rockhampton at 2205 hours for Mackay and was cleared to fly at Flight Level 240. At 2223 hours the pilot called Mackay Tower and reported on descent to 9000 feet. The tower controller instructed the pilot to make a DME (Distance Measuring Equipment) arrival and to report at 10 DME. He advised the pilot that there was a rain shower at the field, moderate rain, and that the visibility was about 6000 metres. At 2227 hours the controller advised the pilot that the weather was improving and the rain showers were mostly to the south-west of the field. He then gave the pilot a choice of left or right circuit and advised that there were a few low patches of cloud. At 2229 hours, the pilot advised that he would be making a left hand circuit for runway 14, (runway 14 is aligned on a magnetic heading of 147 degrees) and the tower controller instructed the pilot to report on final approach. Approximately one and a half minutes later the controller asked the pilot to confirm that the aircraft was making a missed approach. The response from the pilot was "negative". Following this response the controller advised the pilot that the aircraft was very low to the west of the aerodrome and suggested that the aircraft climb. The pilot later reported that he now had the runway in sight and would make another approach. A left circuit was carried out for runway 14 and the aircraft landed without further incident at 2236 hours. Examination of Flight Data Recorder information has shown that at approximately 2231 hours the aircraft was in a landing configuration and aligned with Broadsound Road (part of the Bruce Highway). It subsequently descended to an altitude of 168 feet on the radio altimeter (radio altimeters indicate altitude above ground level). During the latter part of the descent the aircraft was heading 180 degrees magnetic, the same magnetic heading as Broadsound Road, and the computed airspeed reduced to about 137 knots. Witness reports confirm that the aircraft was flown over the highway in a southerly direction, and at very low altitude. An inspection of the area surrounding Mackay Airport and Broadsound Road was carried out in an attempt to ascertain if there were similarities between the runway and the road. Runway 14 is 1981 metres in length and is lit by side variable intensity white lights 65 metres apart. The runway is also equipped with T-vasis approach lights which are used by pilots to determine if the aircraft is above or below the specified three degree glidepath. Broadsound Road is lit by post mounted street lights on either side of the road (approximately 30 metres apart) these run for a distance of about 1200 metres before becoming a single row of lights. The northern end of Broadsound Road is flanked either side by two 24 hour service stations. These provide a intense pool of light either side of the road. There was no similar lighting at the threshold of runway 14. Also, there was no lighting in the area of Broadsound Road that resembles a T-vasis system. It is apparent that the pilot flying the aircraft at the time (the Captain) misidentified Broadsound Road as Mackay runway 14. The flight crew declined to make themselves available to the investigators for interview, apparently under direction from their industrial association. This action by the crew hampered the investigation and resulted in the reasons for the misidentification of the runway not being determined.

The pilot had landed at the one-way agricultural strip in order to deliver covers for a load of superphosphate. The subsequent take-off was normal until the point where the tail of the aircraft was raised. At this time the aircraft was affected by a strong wind gust, and the pilot was unable to maintain directional control. The aircraft ran off the side of the strip and struck scrub and a steel fence post. The wind at the time was relatively strong, giving a substantial downwind/crosswind component. Although the pilot had operated from this strip on numerous occasions, he had not worked from it for about 12 months. The strip posed difficulties because it changed direction to the right over the crest of a hill. Due to a strong left tailwind, the pilot had to maximise the take-off run available. The path chosen, combined with the prevailing wind, took the aircraft off the right side of the strip before it had attained flying speed.

The pilot was carrying out his first cross country flight over unfamiliar terrain. After passing over one of his planned turning points he became concerned about the aircraft's location and decided to follow a road back towards the destination. Enroute the pilot descended the aircraft to read a road sign in an endeavour to establish his location. However, the aircraft struck a power line and subsequently collided with the ground. This accident was not the subject of an on-site investigation.

The pilot had been engaged in fertiliser spreading operations on the property since the previous day. During a meal break between sorties, the pilot and his father discussed the presence of a powerline which crossed a creek on the property. Immediately following the break, the pilot continued with the spreading operation, before turning and following the line of the creek. It was considered that he was proceeding towards an area which required clean-up runs to complete the treatment. The right wing of the aircraft struck and became entangled in the single wire powerline, and the aircraft crashed into the creek bed. A fire broke out on impact and consumed the wreckage. The powerline was suspended from poles on either side of the creek, with a span between poles of 735 metres. The aircraft struck the wire approximately 50 metres above ground level. The weather conditions at the time were fine and cloudless, with no restrictions to visibility. The investigation did not reveal any fault or malfunction with the aircraft which might have contributed to the accident. It is likely that the pilot forgot the presence of the wire, and either did not see it, or saw it too late to take avoiding action. The wire itself was hard to see against the background, and the wide span between supporting poles made the task of detection more difficult. The reason the pilot apparently forgot the presence of the powerline, so soon after specifically discussing it, could not be determined.

The aircraft arrived at the destination strip about 40 minutes after last light. Weather conditions in the area were good, with light winds and clear skies, however the night was very dark and there was no visible horizon. Witnesses on the ground reported that the aircraft seemed to be at a normal height on the crosswind leg and as it turned onto downwind. However, it was then seen to enter a gradual but steady descent. About half way along the downwind leg, the lights of the aircraft were lost to sight. The aircraft impacted the ground in a straight and level attitude, bounced 118 metres, and then bounced and skidded for a further 216 metres before coming to rest. No fault was subsequently found with the aircraft which might have contributed to the development of the accident. The pilot lacked recent experience in night operations. He had made only two night flights in the previous 32 months, the most recent being some 11 months prior to the accident. On the downwind leg of the circuit, the pilot had apparently not increased engine power after the gear was lowered. He had also been concentrating on his position relative to the flare path, and had evidently paid insufficient attention to the height of the aircraft.

The pilot left his home base and flew to the strip from which he intended to conduct top dressing operations. Shortly after a normal take-off with the first load of superphosphate, the engine power suddenly deteriorated rapidly. The pilot dumped the load and landed in an adjoining paddock, but the aircraft collided with a fence and subsequently ground looped. No fault was subsequently found with the engine, which was still operating at idle power when the aircraft came to rest. After arrival at the agricultural strip, the pilot had left the engine idling for several minutes with the carburettor heat selected to the cold position. Atmospheric conditions were suitable for the formation of carburettor icing, and it was most probable that this had occurred. The pilot had been in the habit of using reduced power for take-off, which may have aggravated any tendency for carburettor ice to form.

The pilot was carrying out a survey of various properties he intended to spray in the near future. While climbing to return to Lismore after surveying the last property, the engine suddenly ran roughly and then stopped. The pilot was committed to a forced landing on unsuitable terrain, and the aircraft collided with a windrow of fallen trees 146 metres after touchdown. A fire then broke out and engulfed the wreckage. The subsequent investigation revealed that there had been no failure of the internal components of the engine, however the fire had destroyed many of the accessories, including the carburettor and parts of the fuel system. The fuel filter outlet elbow was not an aircraft standard part, and there was inadequate sealing between this elbow and the fuel outlet hose. However, whether this had any bearing on the development of the accident could not be established, and the cause of the engine failure remains undetermined.