Loss of control

On arrival in the circuit at the destination, the pilot estimated the wind strength at 5 to 15 knots blowing directly across the strip. He elected to land towards the north east with the crosswind from the left. After landing the pilot reported the aircraft was hit by a wind gust which tipped it onto its right wing. The aircraft then weather cocked and ran off the mown section of the strip into long grass where it overturned. This accident was not the subject on an on scene investigation.

At the conclusion of a property inspection the pilot decided to practice a glide approach in 15 knot wind conditions, which gave a light crosswind on the selected strip. Initial touchdown was on the tailwheel and the aircraft bounced. After the next touchdown the aircraft commenced to run off the side of the strip. The pilot applied power to go-around but the propeller struck the ground and the aircraft came to rest on its nose in a paddock adjacent to the strip. When the aircraft bounced, the pilot had not maintained the control inputs required to compensate for the crosswind, and after the subsequent touchdown the aircraft had commenced to weather-cock. Having applied power to go-around, the pilot had progressively pushed forward on the control stick, in the belief that the tailwheel was still on the ground.

The aircraft was to operate a passenger carrying flight to Townsville. Witness reports indicate that the aircraft was aligned on runway 14 in preparation for takeoff. Power was applied and the takeoff run commenced. At the beginning of the takeoff run the aircraft veered to the right and the right mainwheel ran off the sealed runway onto the grass. The aircraft then veered sharply to the left, crossed the runway and ran onto the grass beyond the gable markers. The aircraft then collided with a concrete culvert, crossed a roadway, and came to rest in trees 315 metres from the runway threshold. Comprehensive examination of the aircraft did not reveal any defect or failure that may have contributed to the development of the accident. The weather at the time of the accident was not contributory. The flight crew declined to make themselves available to the investigators for interview. The crew were issued with summonses but did not answer the summons, apparently under direction from their industrial association. This action by the crew hampered the investigation and resulted in no causal factors being determined.

Circumstances:

The pilot was flying a right hand circuit for Runway 35 at a height of about 500 feet above ground level. The aircraft was observed at a base turn position to suddenly bank about 30 degrees to the right, and then to adopt a nose low attitude and begin rotating to the right. This rotation continued until the aircraft struck the ground. No fault was subsequently found with the aircraft which might have contributed to the accident. The pilot reported that he had reduced engine power on the downwind leg because the aircraft speed was too high. He recalled that after the aircraft began rotating, he had pulled the control column backwards, in an attempt to raise the nose of the aircraft and recover to normal flight, but this had no effect. The behaviour of the aircraft immediately prior to impact was consistent with its speed decreasing to the point where the wing(s) stalled and the aircraft entered a spin to the right. The pilot had completed an aerobatic endorsement (including spin entry and recovery) on the aircraft type some five months before the accident. However, he reportedly had only four opportunities to practice spin recovery since then. The attempt by the pilot to recover from the spin by moving the control stick backwards was incorrect and was probably a spontaneous action on his part triggered by the sudden onset of the spin and the low height above ground level at which it occurred.

Significant Factors:

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

1. The pilot did not maintain sufficient airspeed for the conditions involved.

2. The aircraft stalled and entered a spin to the right.

3. In what was probably a spontaneous action on his part, the pilot applied an incorrect technique in attempting to recover from the spin.

Recommendations:

Examination of the cockpit areas of the aircraft showed that the left hand shoulder harness attachment point for the front seat safety harness had failed, possibly contributing to the injuries received by the passenger. The shoulder harness arrangement is that the shoulder straps are attached to a common end fitting which is equipped with a pulley. The pulley is free to move laterally on a traverse cable which is attached via lugs bolted to the left and right upper fuselage longerons. In this case, the lug on the left side had separated from its longeron when the rear of the two attaching bolts failed. The failed bolt was not recovered but probably failed due to a combination of tension, bending and shear loads. The recommendation is made that the Civil Aviation Authority consider requiring either modification of the lug to prevent deformation of its rear end, or replacement of the rear bolt with a larger diameter bolt to prevent local bending of the bolt.

The pilot reported that he intended to carry out a touch and go landing. The approach was normal but after touchdown, the aircraft started to drift to the left. The pilot advised that because of his familiarity with hang glider operations, he used the wrong rudder in an attempt to correct the situation. The nose swung rapidly to the left and the nose gear collapsed. The aircraft came to rest at the edge of the runway.

Circumstances:

The pilot was assessing a new powered trike hang glider which had greater performance capabilities than his own aircraft. He successfully completed several circuits before landing for a short period about one kilometre from the witnesses. The aircraft became airborne again, climbed to about 100 feet and performed a series of short climb and descent manoeuvers. It then entered a very steep angled climb, described by the witness as 80 degrees. At about 300 feet, the sound of the engine ceased, the nose pitched down, and the aircraft entered a series of three "tuck and tumbles", similar to an uncontrolled outside loop. On the third tuck and tumble, both wings failed and came together, and the aircraft fell straight to the ground. At some point, the emergency parachute handle was pulled but there was insufficient altitude remaining and the parachute did not deploy from the container. No pre-existing defects were found with the aircraft. The investigation determined that during the break-up sequence the seat area separated from the section containing the engine, which was still running at ground impact. Ground testing of the engine revealed no defects and the engine continued to run satisfactorily up to simulated angles of 35 degrees of climb. This, together with the 50 degrees freedom of movement for the control bar, would allow a very steep apparent angle of climb to ground observers. It is most likely that the pilot, once the aircraft attained this attitude, closed the throttle, and pulled back on the control bar. This probably initiated the tuck and tumble sequence. It was found that the parachute was attached to the engine, not the seat frame, and that the parachute's performance rating did not match the performance rating of the aircraft.

Significant Factors:

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

1. The pilot's experience was on considerably lesser powered and lower performing ultra-light aircraft. 2. Whilst attempting a very steep climb, the pilot applied incorrect recovery technique.

Recommendations:

1. It is recommended that the Civil Aviation Authority (CAA) and the Australian Ultralight Federation (AUF) review training standards and experience requirements for ultra-light pilots intending to upgrade to aircraft with significantly enhanced performance characteristics.

2. The AUF should encourage manufacturers of trike aircraft fitted with parachutes to ensure that the emergency parachute is attached to the seat frame and is compatible with the performance of the aircraft.

During the landing roll both mainwheels entered soft areas in the strip surface. The aircraft swung through 120 degrees to the left then slid sideways for 17 metres before the right maingear collapsed. The wing struck the ground and was bent upwards. The condition of the strip surface was unsatisfactory because the first 500 metres contained soft spots. The positions of the soft spots were not marked, nor was the strip threshold displaced. The pilot had used the strip previously but on this occasion he did not check its serviceability before the flight.

The pilot had been ridge-flying not far from the glider field, along a range of hills oriented north/south. The coastline was located just west of the range of hills, and a north-westerly wind was providing good lift along the ridge. When a sea breeze developed, the wind changed to a south-easterly and the pilot was unable to maintain altitude or reach the glider field. During the subsequent outlanding the glider sustained damage when the pilot induced a ground loop to avoid striking a fence.

At a height of about 150 feet after a normal take-off, the aircraft commenced to roll slowly to the right. Corrective control inputs appeared to the pilot to have little or no effect and the aircraft continued to roll, with accompanying nose drop and yaw. The right wing tip struck the ground, followed by the landing gear. The gear was torn off and the aircraft overturned, coming to rest across a drainage ditch. No fault was subsequently found with the aircraft which might have contributed to the loss of control. There was no evidence of wind shear or any other atmospheric disturbance. The pilot reported that the engine power, attitude and airspeed had been such that a normal climb should have been achieved. The reason for the accident has not been determined.

The pilot purchased the aircraft the week prior to the accident. He had no aeronautical experience prior to the acquisition and had not undertaken any form of training for ultalight flying. Whilst conducting taxy tests with the control column all the way aft to feel the effects of the controls the aircraft became airborne with less than full power set. After liftoff the airspeed decayed rapidly the aircraft became uncontrollable and dived into the estuary. It is a requirement of the regulations covering the piloting of ultralight aircraft that before acting as pilot-in-command of an aircraft that the pilot undergoes specified training. This accident was not the subject of a formal on scene investigation.