Upon arriving in the area to be sprayed, the pilot carried out an airborne inspection and located the obstacles, including a powerline beside a road just outside the eastern boundary. Three wheat paddocks adjoining each other were to be sprayed. The first spray run was about one and a half kilometres long in an easterly direction. During the run the pilot concentrated on the drift of the herbicide spray and forgot about the power line. He saw the wires a split second before impact. The aircraft struck the north/south power line and severed one of three wires before crashing inverted into the ground about 80 metres beyond the road. Weather conditions at the time were fine and ideal for spraying. This accident was not the subject of a formal on scene investigation.

Circumstances:

On final approach, the pilot observed that the single gear down light (green) was illuminated. Following a smooth touchdown near the threshold, the aircraft rolled along for about 150 metres before the pilot noticed the left side of the aircraft had settled lower than normal. Suddenly the aircraft veered uncontrollably to the left and struck a T vasis light box before coming to rest with the main gear partially collapsed. Post flight inspection revealed that the main landing gear had not been fully extended. Examination of the landing gear system revealed no evidence of pre existing failure or damage. The gear collapse was evidently the result of inadequate maintenance and inspection of the system. This had allowed the gear down light to be illuminated when the maingear had not been locked in the overcentre position.

Significant Factors:

The following factor was considered relevant to the development of the accident:

1. Inadequate maintenance and inspection of the landing gear system.

The pilot had completed his last spray run and had pulled up into a procedure turn to make a clean-up run. He was aware of two power lines, one running parallel to the spray run and the other at an angle to the first. He was intent on avoiding the line at an angle to his run but struck the other as he positioned for the clean-up run. Visibility at the time was reduced in light rain. The line hit the right wingtip and windshield wirecutter. Thw wirecutter bent under the load and the wire broke the windscreen and tore off the top of the cockpit before it separated. The pilot was able to recover the aircraft without further damage.

The pilot was to land the helicopter in a clearing which was some 80 metres in diameter and surrounded by trees up to 20 metres tall. He conducted a 40 knot power check some 200 feet above the trees and concluded that he would be able to hover the aircraft out of ground effect with 1-1.5 inches Manifold Air Pressure (MAP) margin. The helicopter was landed in the clearing without incident. To depart the clearing one hour later, the pilot set 31" MAP/3100 rpm (full power is 32" MAP/3200 rpm) and climbed the helicopter at about a 60 degree angle. He reached tree-top height and had just started to accelerate the aircraft when it began to settle. The pilot immediately applied full power and full collective pitch but was unable to arrest the descent. Although the engine rpm decayed to below 2500, the pilot was able to manoeuvre the helicopter into a confined area and land adjacent to a creek bed. Just prior to touchdown, the main rotor blades hit the trunk of a dead tree. No fault was found with the helicopter which might have contributed to the accident. The pilot had limited experience in high weight operations into confined areas. The pilot described the wind as light but varying substantially in direction at times. The power check conducted by the pilot would have been valid only if conditions at takeoff were exactly the same as those existing at the time and place of the check i.e. 200 feet above the tree tops and one hour before the accident. There is no guarantee that conditions were the same and 1-1.5 inches MAP was not sufficient buffer in the circumstances to ensure safe operations. By climbing at 60 degrees, the pilot was committing himself to the takeoff without any fall-back option. The correct technique required the helicopter to be climbed vertically in a "towering lift" type DEPARTURE.

The pilot departed on a mail run to his first port of call at Yalcowinna. He was unable to land, as the strip was covered with water from recent heavy rains. He diverted to the next strip at Mawarra, and recalled overflying the strip which he assessed as being wet but suitable for landing. The strip owner usually contacted the aircraft by radio to advise on the surface conditions, but on this occasion the pilot was unable to make contact before landing. The aircraft became bogged after turning off the strip following landing. After being extricated and the turnaround completed, the aircraft again became bogged while taxiing for takeoff. After once again freeing the aircraft, the pilot positioned it at one end of the strip ready for takeoff. He then shut the engine down, left the aircraft and inspected the strip from a vehicle. Having assessed the surface as suitable, the pilot attempted a takeoff with two stages of flap extended. At a previously selected decision point, the pilot elected to continue the takeoff and attempted to lift off at an indicated airspeed of 50 knots. The aircraft settled back onto the strip on the main wheels, and remained in this nose high attitude until the pilot decided to abandon the takeoff. The aircraft came to rest about 1400 metres beyond the end of the 700 metre long strip, after passing beneath telephone wires which stood some 200 metres past the strip end. The nosegear collapsed towards the end of the ground roll. The pilot did not recall being briefed by his employer that he should not land at Mawarra if Yalcowinna was unserviceable due to surface conditions.

The pilot was conducting agricultural spraying operations on a paddock which had a powerline crossing it at an angle and a fence along the western boundary. On completion of a spray run to the north, the pilot returned for a run to the south along the fence line. The marker was required to climb over the fence into the next paddock and move away from the flight path of the aircraft, prior to the commencement of the run along the fence. As he approached the powerline, with the right wing almost over the fence, the pilot noticed that the marker had delayed climbing over the fence. He took evasive action to avoid striking the marker and during this attempt the aircraft contacted the powerline. The aircraft deflector cable failed, allowing the power line to sever the rudder from the aircraft. The pilot carried out a precautionary landing on a road. During the landing roll, the left brake failed and the aircraft ground looped. The investigation revealed that the pilot misjudged the clearance between the aircraft and the powerline. The deflector cable was severed by the impact with the powerline and the rudder was torn from the aircraft. The left main landing gear leg was found to have failed from a combination of bending and twisting. It is considered likely that the brake failure occurred as the leg and attached brake line were torn from the aircraft, depriving the pilot of directional control. There were no pre-existing defects with the aircraft which could have contributed to the accident.

The pilot was landing at a strip aligned 070 degrees. He estimated the wind to have been gusting 20-25 knots from 090-120 degrees. Neither drift nor turbulence were excessive on finals. However, as the aircraft was flared, it suddenly rolled rapidly left to what the pilot judged was more than 60 degrees of bank. Despite the application of full power and opposite rudder, the pilot was unable to prevent the left wing contacting the upper branches of trees to the left of the strip. This resulted in the aircraft striking the ground nose first and coming to rest 80 metres left of the strip. The conditions existing at the time of the accident were such that strong wind gusts were possible. Other pilots who had used the strip reported experiencing wind gusts at a similar stage of the approach.

The pilot had earlier landed in the paddock which was adjacent to the homestead to seek assistance regarding a broken down vehicle being used in the spraying task. Prior to commencing the takeoff run the pilot did not inspect the proposed takeoff path. Initially the aircraft takeoff run acceleration was more sluggish than normal, due to the traversing of patches of soft wet ground. Acceleration improved. However, the aircraft was approaching some trees so the pilot turned it to provide a greater ground roll distance. The aircraft became airborne for a short time, but then touched down in long wet grass which degraded its acceleration. It then hit a fence and nosed over.

The pilot was conducting a bank-run flight. It was raining heavily when the aircraft arrived at Canberra, and the pilot took shelter while freight agents attended to the load. When this operation was completed, the pilot ran back to the aircraft, quickly boarded and prepared for DEPARTURE. Although Runway 35 was the runway in use, he was given a taxy clearance for DEPARTURE from Runway 12, as the cloud base and visibility were better in that direction, and the wind was light and variable. It was still raining as the takeoff roll was commenced, with water accumulation on the runway retarding the acceleration of the aircraft. At the start of the roll the pilot heard a tapping noise coming from the left hand side of the aircraft, which he thought may have been a strap from his seat belt hanging out of the door, but a quick check confirmed that his seat belt was correctly fastened. As speed increased the noise subsided, and as both engines appeared to be operating normally, the takeoff was continued. However, at the point of rotation the noise returned, louder than previously, and the pilot suspected that there was a fault in the left engine. As it was apparent that the aircraft would enter cloud shortly after becoming airborne, the pilot made a decision to abandon the takeoff. The aircraft touched down approximately 550 metres from the end of the runway, and during the application of heavy braking the aircraft aquaplaned along the wet runway. After crossing the threshold it continued through the boundary fence, across a road, then came to rest in an adjoining paddock. A length of the cargo restraint webbing was found hanging out of the cabin door, allowing it to flap against the side of the fuselage. Canberra Runway 12/30 has a known drainage problem during rain periods, and other aircraft have also experienced aquaplaning following abandoned takeoffs.

The aircraft had been constructed by the pilot in his engineering workshop from plans supplied by the designer, Bushby Aircraft Incorporated of Minooka, Illinois, USA. During some stages of the construction the pilot had been assisted by Mr R.S. Howarth. The first flight of the aircraft had been achieved on 5 April 1982 and by the day of the accident some 50 hours had been flown, with Mr Waggott being the pilot on each occasion. The only known problems of significance that had been encountered during this period was wind noise and rattling associated, apparently, with the canopy. On 3 July 1982 the pilot had been carrying out adjustments to the wing root fillets, again apparently to reduce wind noise. The pilot was then joined by Mr Howarth and after boarding the aircraft the pilot advised Bankstown Tower that they would be proceeding to the Bankstown training area. The aircraft was cleared for take-off and the response to that clearance at 1433 was the last recorded transmission from the aircraft. The aircraft is not known to have been seen by any other persons until about 1508 when ground witnesses observed it about two and a half kilometres south-east of Luddenham, heading in a south-westerly direction. The witnesses reported that the engine noise sounded uneven and that the aircraft was rolling to the right. Other witnesses further along the flight path observed what they referred to as "confetti" floating down from the aircraft. It crossed the Luddenham - Bringelly road and as it passed over Vicary's Winery pieces of plexiglass, the cockpit canopy and the occupants headsets, glasses and caps fell to the ground. The aircraft continued in a south-westerly heading, descending toward open country in substantially a level attitude, then rolled to the right and impacted the ground in an inverted attitude near a house. Inspection of the wreckage found no defect or malfunction that would have affected the safety of the operation existed, except that the canopy had become detached in flight. Examination of the canopy revealed that it had not been manufactured in accordance with the aircraft designers plan. Different specification material had been used in the frame of the canopy and this had in turn been reduced in strength by the drilling of holes to allow the access to the nuts of the plexiglass attachment screws. The attachment of the canopy keeper brackets was also altered so that only one screw, instead of the designers intended three, held brackets to the roller assembly. Also the canopy latch mechanism had been altered so that it did not provide positive restraint in a vertical direction. The aircraft designer indicated that the loss of the canopy in flight should not have affected the pilot's ability to safely control the aircraft. Marks on the occupants headsets showed that they had been struck by the canopy, and it was considered probable that the occupants had been incapacitated as the canopy detached. ((1))