Loss of control

The pilot was approaching to land in what he believed were light wind conditions. As he crossed the threshold he realised that there was a tailwind component, but elected to continue the approach. Touchdown occurred with about 415 metres of the strip remaining. During the landing roll the pilot became concerned that the aircraft would not stop before the boundary fence, and a ground loop was attempted. The left maingear collapsed as the aircraft came to rest 103 metres from the end of the runway. The landing attempt had been made in 12 to 15 knot downwind conditions. The pilot had assessed the wind direction from the smoke emitted by nearby power stations. He had not noticed the direction indicated by the two windsocks at the aerodrome. It was likely that the pilot was mentally fatigued following a long and difficult day at his workplace, and he may have been pre-occupied with business matters which were related to the reason for the particular flight.

The pilot, who is an approved AUF instructor, was conducting a solo test flight, following complaints by a student that directional control was more difficult than normal. During the takeoff run a rudder lever arm collapsed, directional control was lost, and the aircraft collided with a fence. It was likely that the directional control problems originally reported were related to the rudder lever arm being bent. The reason for the bending was not established, but the lever had evidently been weakened to the point where it failed during the attempted takeoff.

Circumstances:

The student pilot was landing the aircraft during his second period of dual instruction on type. Shortly after touchdown the aircraft was struck by a wind gust. Despite corrective action by the instructor, directional control was lost, and the aircraft ran off the runway, substantially damaging the tail boom.

The pilot was spraying a small paddock, to the south east of which the ground rose steeply. All spraying runs were being conducted towards the south east, with the pilot carrying out left hand orbits at the end of each run in order to reposition the aircraft. However, manoeuvring in this manner was taking the aircraft close to houses in a noise sensitive area. The pilot therefore decided to carry out a procedure turn and conduct a run into the north west. About half way around this turn the aircraft lost performance, probably as the result of a downdraft, and then stalled at about 100 feet above the ground. There was insufficient height available for the pilot to effect recovery and the aircraft struck the ground in about a 30 degree nosedown attitude. The pilot subsequently advised that he was aware that downdrafts were likely to be present in the prevailing conditions. However, he had been concerned to avoid the noise sensitive area, and had not considered the possibility of downdrafts as he manoeuvred over rising terrain. When he was attempting to recover from the stall situation, the pilot had not dumped his load because there were valuable animals in the paddock below the aircraft.

As part of the final phase of the rating test, the pilot was required to spray a paddock. An inspection of the area to be treated was carried out. During the procedure turn at the end of the second spray run, the nose dropped and the aircraft struck the ground in a near vertical attitude. The pilot had incorrectly assessed the wind direction and had carried out the procedure turns at the end of the spray runs in the wrong direction. In an effort to align the aircraft for the next run, the pilot tightened the turn and the aircraft stalled.

The pilot intended to conduct a practice aerobatic flight, and had arranged for an observer on the ground to monitor and assess his performance. The planned sequence was commenced, but the observer noted that the second manoeuvre was not completed satisfactorily, and the aircraft apparently stalled while inverted. After recovering from this situation, further manoeuvres were carried out. Other witnesses suggested that the entries to some of these manoeuvres were performed at higher "G" loadings than normal. The aircraft subsequently entered a spiral dive, which was continued without any apparent effort being made to effect recovery. The aircraft maintained the spiral until it collided with power lines, then impacted the ground. A fierce fire broke out and consumed the wreckage. A detailed investigation failed to discover any defect or malfunction with the aircraft or its systems which might have contributed to the accident. The pilot had been in current practice for aerobatic flight, and there was no evidence of any physical illness or incapacity which might have affected his ability to control the aircraft. However, it was evident that the aircraft was not under control during the spiral dive. It was considered possible that the pilot might have lost consciousness as a result of either a rapid increase in "G", or sustained high "G" loads applied during the preceding aerobatic sequence.

Just after lift-off for spraying operations the aircraft sank back to the ground and drifted to the left. The pilot dumped the load but the aircraft became entangled in a fence running along the left side of the strip. The pilot stated that at a height of about 20 feet the aircraft appeared to encounter a wind gust from the right rear quarter. The aircraft was heavily laden and the pilot had been unable to regain full control before the collision with the fence.

Circumstances:

All the pilot's previous flying experience was in conventional aircraft. He had operated this aircraft only to the extent of conducting short "hops" along the strip. On this occasion however, he became airborne and flew for about 15 minutes before approaching to land. On late finals as the aircraft flared for landing, the engine power was heard to increase and then decrease. At the same time, the aircraft began to porpoise. The right wing and then the nose struck the ground before the aircraft nosed over.

The pilot had not flown the aircraft type for 2 months. After a period in the training area he approached to land on the 17 strip. The wind was from the south-east at 5 to 10 knots. During the ground roll brake was applied, but the aircraft diverted to the right side of the strip. The pilot corrected for this, but the ensuing left turn tightened and the right maingear collapsed. The aircraft came to rest 480 metres into the strip. It was determined that the gear leg had failed from overload forces. An inspection of the cockpit revealed that the throttle was partly forward, suggesting this may have been a factor in the longer than normal landing run and the problem of directional control of the aircraft. This accident was not the subject of an on scene investigation.

The pilot was engaged in spraying a crop of lupins. The aircraft was observed to fly from one paddock to another on the property. A short time later a tree in that paddock was observed to be on fire. The wreckage of the aircraft was later found in the paddock. The aircraft had struck the ground in an inverted attitude and was completely burnt out by the ensuing fire. No evidence of aircraft failure or pilot incapacitation was found. The reason for the loss of control leading to the accident could not be determined.