During ridge soaring operations, areas of sink were encountered and the aircraft descended over forested terrain. The only area suitable for an outlanding was a small deer enclosure. The pilot initially overshot the area and during the turn to re-position the aircraft for landing the right wing struck the fence surrounding the enclosure. The aircraft yawed through 90 degrees before impacting the ground in a level attitude. Although general soaring conditions were poor, the pilot had elected to leave the ridge-line to conduct a sight seeing flight. During this flight a wind change moved through the area. On return to the ridge-line the pilot, who had not detected the wind change, persisted with efforts to find an area of lift. The proximity of the aircraft to the tops of the trees and the small size of the deer enclosure precluded the pilot sighting the clearing in time to conduct a straight-in approach.

On arrival at a sloping helipad, the pilot overflew the pad to ascertain that it was clear, and made a final approach to the pad. During the landing two of the main rotor blades struck the surface of the slope. The investigation was carried out by the Department of Civil Aviation Malaysia.

The pilot was departing into strong and gusty wind conditions. The aircraft was observed to climb steeply to about 200 feet above ground level. It then entered a descending turn to the right, at a low airspeed. The descent continued with the aircraft in a nose high attitude, and a wing was seen to drop shortly before ground impact. The pilot subsequently reported the engine was delivering full power throughout the flight. Another pilot who had flown a number of flights in the area during the day, reported that he had encountered pronounced areas of sink to the north of the strip. It was considered that while attempting to fly out of similar conditions, the pilot had allowed the airspeed to decay and the aircraft had stalled. There had been insufficient height available for the pilot to effect recovery. This accident was not the subject of an on-scene investigation.

Circumstances:

The pilot was undergoing a check flight with an instructor, as he was contemplating purchasing this type of aircraft. This was the first occasion that the pilot and instructor had flown together. A series of exercises was carried out, during which the pilot was asked to demonstrate a power on stall at a height of approximately 500 feet. During this exercise, the pilot did not lower the nose sufficiently during the recovery. The pilot was not accustomed to practising stalling at such a low altitude, and during his previous training this had been carried out at 1500 feet. After some discussion another stall recovery was carried out, and on this occasion the pilot used the correct technique. The instructor then decided to return to the strip to carry out some circuits and landings as he assessed the pilot to be unsuitable to fly solo. The flying technique required by the instructor was generally at variance to that previously experienced by the pilot, and it would appear that the check flight was rather vigorous without the opportunity to become accustomed to the environment. During the return flight, the instructor described the circumstances which could cause the aircraft to stall during a forced landing with no power. To demonstrate this, he then closed the throttle at a height of between 300 and 500 feet, and asked the pilot to adopt a glide attitude, initiate a stall and then effect a recovery without the use of engine power. The pilot did not lower the nose sufficiently after the stall symptoms appeared, and he was told to further lower the nose, as a steep nose down attitude is required to effect this type of recovery. When the pilot did not commence to ease the aircraft out of the ensuing dive, the instructor called that he was taking over, but he was unable to move the controls. The pilot had become rigid at the controls, the instructor was unable to correct the situation, and the aircraft remained in a pronounced nose down attitude until ground impact.

Significant Factors:

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

1. The instructor was carrying out stalling practice at a low height.

2. The pilot mishandled the controls, probably due to misapprehension.

3. The pilot apparently panicked and became rigid on the controls when the aircraft was in a steep nose down attitude near the ground.

4. The instructor was unable to regain control of the aircraft before it struck the ground.

Recommendations:

The Civil Aviation Authority in conjunction with the Australian Ultralight Federation, should consider specifying minimum heights above ground level for ultralight aircraft engaged in stalling, spinning and unusual attitude recovery practice.

Circumstances:

The aircraft was taking off shortly after the pilot had carried out modifications to the fuel system. This had included removing and replacing fuel lines. A witness reported that prior to commencing the take-off, the engine had been misfiring. This had continued during the take-off run and initial climb until the engine stopped at a height of about 150 feet. The aircraft was seen to turn sharply to the left before entering a steep nose down spin. After about one full turn the aircraft struck the ground near the strip end. The pilot, who was not wearing a helmet, suffered a fatal head injury following the failure of his upper body restraint on impact. The reason for the loss of engine power could not be positively determined.

Significant Factors:

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

1. Undetermined loss of engine power after take-off.

2. Pilot attempted operation with known engine deficiency.

3. Pilot encountered circumstances beyond his capability.

Recommendations:

As a result of the initial investigation, the Australian Ultralight Federation was notified of the failure of the restraint system, together with a recommended solution. The AUF issued an Airworthiness Advisory on the subject in January 1990.

The company was tasked to operate into a strip adjoining a local race course. Details of the strip were obtained from a local pilot, who told a company pilot that there was a powerline at the eastern threshold of the strip. This pilot subsequently gave the strip data to the pilot who flew the aircraft. Upon arrival overhead the strip, the pilot saw powerlines off the western end and thought that these were the lines mentioned in the briefing. He then decided to land into the west. On late final approach, he saw the powerlines over the threshold and flew the aircraft under them. The resultant high rate of descent could not be arrested before ground impact and the aircraft struck the ground in a nose low attitude with the nosegear and propellers. The landing gear and propellers were torn off and the aircraft slid for 112 metres before coming to rest. The cabin was protected from high deceleration forces by the collapsing landing gear and the occupants escaped without injury. It was determined that the strip was not suitable in length or width for the operation of this aircraft type, and the briefing obtained on the strip was not adequate to determine the suitability of the strip.

After a short flight in the local area the pilot made a long low final approach towards the intended landing point. During the approach the pilot temporarily forgot that powerlines crossed the flight path. The aircraft collided with the wires, which were 68 feet agl, and struck the ground in a vertical nose-down attitude about 800 metres from the landing area.

Circumstances:

The owner of the weight-shift controlled aircraft was being given dual instruction in circuit procedures. This involved making normal approaches followed by a low-level go-around. During the fourth go-around, at a height of about 50 feet, the engine suddenly stopped. The instructor took over the controls and attempted a landing in a sparsely wooded area adjacent to the landing strip but was unable to prevent the aircraft from colliding with a tree and striking the ground heavily. A specialist examination failed to reveal any defect with the engine or fuel system. The reason for the engine stoppage could not be positively established. However, the ROTAX 532 engine was fitted with a single ignition system controlled by an unguarded toggle switch mounted on a console in the forward cockpit. The circumstances of the engine stoppage were consistent with the ignition switch being inadvertently bumped off by the front seat pilot.

Significant Factors:

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

1. The engine stopped at a critical stage of the go-around. The reason for the stoppage could not be positively established.

2. Unfavourable terrain for forced landing.

Recommendations:

The Australian Ultralight Federation (AUF) should require ignition switches be fitted with guards to prevent inadvertent movement on all AUF registered aircraft.

The flight was planned to check the onboard survey equipment. After departing Jandakot the aircraft operated to the south of the airfield for about 80 minutes before the pilot advised that he would be extending his operation to the east over the Darling Ranges. The aircraft was then sighted, by several witnesses, over the foothills heading in an easterly direction. These witnesses reported that the engines were not operating normally. A short time later, the aircraft was observed to pass over the dam wall at an altitude of about 25 feet and head down a valley in a northerly direction before disappearing from sight. An inspection of the wreckage indicated that the aircraft had collided with two 30 metre high trees, in a nose high attitude at a low forward airspeed, before falling to the ground below the trees. At impact neither engine was delivering power. The fuel system, which was found to be relatively intact, contained only nine litres of fuel. It was determined that the engines failed due to fuel starvation following the exhaustion of the useable fuel onboard the aircraft. The pilot was then faced with attempting a landing in unsuitable terrain. Evidence indicates that the aircraft departed Jandakot with both the fuel quantity indicating systems unserviceable. Although the maintenance documentation for the aircraft did not indicate that these systems were unserviceable, it is believed that the pilot was aware of the maintenance state of the aircraft before DEPARTURE.

After takeoff, the aircraft was observed to accelerate at a low height above the strip. At the upwind end, the pilot initiated a steep climb and a steep turn to the right, however the aircraft stalled at about 150 feet above the ground. The aircraft struck the ground heavily and slid into a ringlock fence. The pilot freed himself from the wreckage, and the engine which was still running at high speed, was shut down by a spectator. The pilot reported that after the ultralight stalled, he had the stick full back, but the aircraft would not recover. The aircraft stalled as a result of the steep climbing turn but recovery was not effected due to incorrect stall recovery technique.