Circumstances:

The aircraft was making an intermediate landing for refuelling before proceeding to Lord Howe Island. The pilot reported that soon after carrying out his pre-landing checks on crosswind leg for runway 28, the right engine failed completely. He identified the engine and feathered the propeller. On downwind leg he carried out a trouble check and attempted three times to unfeather the propeller but was unable to do so. He broadcast that he was turning base for an asymmetric landing, reselected gear down, and lowered full flap in stages on final approach. After flaring, the aircraft floated a considerable distance. Approximately halfway along the 696-metre grass strip, while still airborne, the pilot elected to go around. He applied full power to the left engine, selected gear up and retracted flap in stages as the aircraft started to climb. The aircraft then began an uncommanded roll to the right, associated with a loss of directional control, and the right wingtip struck an aircraft parked about 100 metres to the north of the runway 28 centreline. It then cartwheeled across an adjacent car park before coming to rest a few metres short of a refuelling depot. The pilot had elected to use runway 28, although runway 03/21 was available with a landing distance available of 1586 metres. At the time of the accident the wind was reported as light and variable. The right engine was test run, using the original propeller which had sustained only minor damage. No fault could be found through the entire power range and restarting from the feather position was accomplished without problem.

Significant Factors:

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

1. Loss of power on the right engine, for undetermined reasons.

2. The asymmetric approach was poorly planned.

3. The pilot delayed his decision to initiate a single-engine go-around.

4. The pilot did not obtain/maintain flying speed, resulting in loss of control.

This aircraft was intended to be the production version of the "Stratos" aircraft. The prototype version had successfully flown some 340 hours. The production model incorporated significant changes made by the designer/pilot. These changes included the removal of the dihedral from the main wing and the use of full span elevators on the canard wing and full span ailerons on the main wing. The engine mounting was lowered such that the ducted propeller was totally below the main wing and the lower part of the propeller duct was extended well forward to form a "channel or strake". The main purpose of the "channel wing" was an attempt by the designer to lower the stall speed of the aircraft to 30 knots and to reduce both landing and takeoff speeds and distances. As far as the investigation could determine, the effect of these modifications had not been checked by wind tunnel or other methods prior to this flight. On the day of the accident the pilot and his assistants had worked at the factory preparing the aircraft for testing. The preparation included a determination of the centre of gravity, although no record was kept of these calculations. Following these preparations the aircraft was loaded onto a trailer and taken to Penfield. The weather conditions at the time were fine, with light winds. The pilot subsequently carried out a series of taxying tests, to establish the optimum position for the control column. He then conducted a take-off, and operated in the local area for about 17 minutes. Witnesses reported that the aircraft then carried out a very slow pass over the aerodrome at a height of between 400 and 500 feet above ground level. About one minute later it was seen to turn back towards the strip. However, shortly after the turn was completed, control of the aircraft was evidently lost. It is uncertain whether the aircraft suddenly pitched nose up or nose down, but all witnesses agreed that it then fell vertically while the nose swung in a pendulous motion. The aircraft struck the ground in an inverted attitude with little or no horizontal speed. An inspection of the aircraft found that all airframe components were essentially intact and there was no indication of any airframe or control failure prior to ground impact. The engine was test run and strip inspected and no fault could be found. No aerodynamic testing was carried out on the airframe to determine the likely effect on performance of the various modifications made to this aircraft. However, given that the prototype appeared to suffer no adverse flying characteristics, it is possible that the modifications incorporated in the new aircraft had an adverse effect on the stall characteristics. Analysis of the modifications indicates that the most significant effect on the stall characteristics would have resulted from use of full span elevators on the canard wing. The use of full span elevators results in a relatively uniform loading of the canard as the elevator is deflected approaching the stall. The result is that the canard would be developing more lift, compared to the same wing without full span elevators, before the wing stalled and the stall would be sharper. Because the main wing is still producing lift at this stage the nose down pitch following the stall of the canard would be aggravated. It is considered likely that the accident sequence was initiated by a full canard stall followed by a rapid nose down pitch. Also, the altitude at which the flight was conducted would not have allowed the pilot time to make the necessary corrective control imputs following the stall before the aircraft impacted the ground.

The pilot reported that the helicopter was cruising at 2000 feet when, without warning, there was a complete loss of engine power. During the subsequent forced landing, the tail boom struck the ground, causing the tail rotor gear box to separate from the aircraft. Investigation revealed that the engine accessory gear train had failed, causing both magnetos to cease operation. The gear train failed due to lack of torque followed by the fatigue failure of six screws that attach the accessory drive gear to the starter gear. The cause of the loss of torque was not established.

Prior to the flight the pilot had contacted the owners to obtain details of the strip. This briefing apparently did not include the information that the surface of the strip was undulating and had soft sandy areas. After arriving over the destination the pilot flew along the strip a number of times to check the surface. The wind was calm and he elected to land down the slope. The aircraft bounced and floated along the strip before touching down again. During the landing roll, the nosegear leg failed. The pilot was holding the control column in the neutral position during the landing roll. An aircraft engineer who inspected the aircraft found no evidence of any pre-existing fault in the nosegear leg. This accident was not the subject of a formal on scene investigation.

Circumstances:

The aircraft had taken off from runway 29R when, at a height of about 80 feet, the engine suffered a substantial loss of power. A forced landing was carried out onto a cleared area, beyond the end of the runway. The nose gear collapsed as the pilot attempted to ground loop the aircraft to avoid fences. Investigation revealed a non-standard fuel strainer drain had been fitted in the fuel supply system between the fuel tank and the engine driven pump. Stress corrosion cracking caused failure of the strainer drain adapter fitting and allowed fuel to leak from the engine fuel supply. The diminished fuel supply was insufficient for the engine to maintain power.

Significant Factors:

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

1. Unauthorised modification of the fuel strainer drain system.

2. Stress corrosion failure of the fuel strainer drain adapter fitting.

3. Insufficient fuel supply to the engine to maintain power.

The pilot contacted Cairns Tower at 30 miles DME (Distance Measuring Equipment) inbound on the 153 radial (south-south-east of Cairns), and was subsequently cleared to make a visual approach at 2053 hours. At 2054 hours the pilot was given clearance to land on runway 15, and at 2056 hours he reported that he was making a missed approach because he had lost visual contact with the runway. The aircraft was given instructions to make a standard missed approach, and to intercept the localiser via the 15 DME arc (15 miles north of Cairns) for an ILS (Instrument Landing System) approach. At 2104 hours the pilot reported that he was "having a little trouble" and would like to go around again and make another approach from the 18 DME arc (18 miles north of Cairns). After subsequently being cleared for final approach on the ILS, the pilot then reported that he was "having trouble with radio aids" and would like to climb to 7000 feet. The aircraft was later cleared for a further instrument approach and landed at 2131 hours. The next day, checks with the company revealed that no aircraft unserviceabilities had been reported by the pilot and that the aerodrome ground radio aids were all functioning normally during the arrival of VH-TAI. No report had been made to the company by the pilot concerning any irregularities during the flight. A readout of the Flight Data Recorder was carried out to ascertain the track and altitude profile of the aircraft during the approaches at Cairns. This revealed certain irregularities including a Ground Proximity Warning "Pull Up" signal which operated for between 6 and 10 seconds at 2055 hours. This device is to warn the pilot when the aircraft is in danger of collision with terrain. The warning is considered to have been genuine as the terrain closure rate at this time was in excess of 6100 feet per minute, and the aircraft was in the vicinity of Earl Hill which is 722 feet above sea level. The weather at the time was overcast but fine at the aerodrome. There were rain showers in the area, and visibility was reduced to 4000 metres in rain showers. The two preceding aircraft had been able to make visual approaches. The 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 causal factors of the occurrence not being determined.

The pilot was operating on a Search and Rescue watch manned from the homestead. When the aircraft did not arrive by the appointed hour, the owner of the station conducted an aerial search and found the pilot by the disabled aircraft. The pilot reported that he was attempting to land beside the portable cattle yards when he backed off to avoid the dust clouds thrown up by the main rotor. In doing so, the tail rotor struck a tree obscured by the dust. An immediate landing was initiated but a heavy touchdown resulted. The tail rotor blades separated from the aircraft before the engine was stopped and the tailboom and skids were twisted from the impact with the ground.

The pilot carried out a normal circuit at his destination and obtained a gear green indication. A visual check in the engine cowl mirror also showed the nose gear to be in the fully extended position. The pilot also recalled seeing three greens on his gear check on final approach. Following a normal touchdown, the nose gear collapsed and the aircraft slid to a stop on the runway. The aircraft was subject to an identical occurrence at Kimba on 16 June 1988. The hydraulic power pack was found to be in a poor condition at overhaul. The poppet-valves and check-valves were worn. The nose gear is held in the down position by hydraulic pressure and by an over-centre lock. When the gear selector is placed in the gear down position, the down line is pressurized and the gear extends. When the pressure in the down line reaches system pressure the gear selector lever automatically returns to neutral and forms a hydraulic lock in the down line. However, with the worn valves in the power pack this pressure bled away leaving only the over-centre feature to hold the nose gear in the extended position. The Kimba strip has a rough surface. It is believed that the rough surface caused the over-centre mechanism to become unlocked and since the hydraulic pressure had bled away, the nose gear collapsed.

Circumstances:

The pilot was conducting spraying operations over a millet crop which was approximately 1.5 metres high. Towards the end of the spray run, the aircraft flew under two wires which were about 5.6 metres above the ground. Weather conditions were ideal with high overcast cloud and a light southerly wind. On the second spray run, the aircraft struck the powerlines. The aircraft's wire deflector cable was broken, and the wires then struck the vertical fin, one 50 millimetres from the top and the second 150 millimetres from the top. The wires then tore the tail fin off the aircraft, leaving the rudder trailing by its control cables. The aircraft was seen to pull up abruptly to a height of approximately 150 feet, turn left and head toward open paddocks one kilometre away. Shortly after, it descended rapidly into a crop about 300 metres short of open paddocks, coming to rest 19 metres from initial impact. Engineering examinations found that the elevators had been fouled by the trailing rudder. It is probable that the pilot experienced difficulties with elevator control, resulting in loss of control of the aircraft.

Significant Factors:

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

1. There was insufficient clearance between the crop and the powerline for the aircraft to safely fly under.

2. The aircraft struck the wires which resulted in the rudder trailing by its control cables.

3. The trailing rudder interfered with elevator control, probably causing the pilot to lose control.

Circumstances:

The aircraft was loaded with approximately 80 litres of fuel and 220 litres of spray. The pilot had intended to taxi to the far end of the 570 metre long paddock in order to take-off into wind but at the last moment he noted that the wind was very light. He elected to take-off from his current position with a rear quartering wind. Full power was applied and the aircraft accelerated normally. Approximately 50 to 100 metres from the boundary fence the pilot rotated but the aircraft failed to become airborne. He commenced to dump the load, but the aircraft remained on the ground. The aircraft then ran through the boundary fence and collided with a small embankment collapsing the main gear. The pilot then noticed that the wind strength had increased to approximately eight knots which increased the tailwind component. A performance analysis estimated that under the prevailing conditions reported by the pilot the aircraft required 500 metres for take-off. Although it was possible for the aircraft to take-off in the available paddock length it is obvious that a small error in estimated wind velocity or paddock slope would have increased the take-off run to more than was available. It is likely that this was the case. This accident was not the subject of a formal on-scene investigation.

Significant Factors:

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

1. The take-off was made with a tailwind stronger than that estimated by the pilot.
2. The take-off distance available was insufficient for the planned operation.