Wirestrike

The pilot was a member of the French team competing in the "Austraglide `86" gliding championships. At the end of a cross-country exercise the pilot reported that he was 5 kilometres from the finish line. The pilot of another glider observed that when the subject aircraft was one kilometre from the line it was apparently low. Shortly afterwards the glider collided with power lines. The tailplane was cut off by this impact and the glider then struck the ground in a steep nose down attitude. The glider was seen leaving an area of thermal activity with apparently sufficient altitude to complete the flight to Benalla. The reason why the glider subsquently descended to the low altitude which resulted in the collision with the power lines could not be determined.

Circumstances:

The aircraft was engaged in the final stages of a pasture spraying operation. The area of operation was a small field surrounded by trees. A powerline was located beyond the trees at the southern end of the field. After committing the aircraft to a low-level pass towards the south, the pilot remembered the partially concealed powerline but was unsure of its exact position. When the powerline became visible against the skyline, the pilot realised that he would be unable to pull up over it and elected to fly through the treetops beneath the powerline. Right wing impact with the trees caused the aircraft to yaw and the rudder to strike the powerline as the aircraft passed beneath it. Despite right wing and rudder damage, the pilot retained control and landed the aircraft in the adjacent paddock where he evacuated the aircraft without assistance or injury. Examination of the aircraft determined that there were no pre-existing mechanical defects, abnormalities or damage which can be considered as factors in, or contributory to, this accident. The pilot acknowledged that he did not conduct a specific check of powerline positions before commencing the clean-up run. The pilot had re-commenced agricultural flying, three weeks prior to the accident, after approximately 9 months of fish spotting operations.

Significant Factors:

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

1. The Pilot-in-command failed to conduct a "Supplementary Wire Hazard Check" prior to commencing the clean-up run.

2. The Pilot-in-command lacked recent calendar experience in agricultural operations and below obstruction height flying. 

Recommendations:

1. That the Civil Aviation Authority give consideration to reducing the calendar period nominated in Civil Aviation Orders section 40.6 para 11, "Recent Experience Requirements", from 12 months to 90 days.

2. That the Civil Aviation Authority specify a syllabus for, and the qualification of the person conducting, agricultural proficiency checks in accordance with Civil Aviation Order 40.6.

The pilot had been spraying a wheat crop for about 30 minutes. He advised that difficulties were encountered with the stabilisation of the spray pressure. While attempting to adjust the pressure control he temporarily forgot the proximity of three high voltage power lines which crossed the crop. The aircraft collided with these lines and pitched down steeply to the ground. Fire broke out on impact and engulfed the wreckage.

Circumstances:

The pilot conducted an aerial survey of the property to be sprayed. He observed main power lines running from east to west, and a spur power line running north to the homestead. During the final clean-up run of the paddock, whilst flying from west to east, the aircraft's fin struck the spur power line, which was across the flight path, and had been forgotten by the pilot. The wire strike severed the top of the fin and rudder which resulted in the aircraft impacting the ground and coming to rest 90 metres from the power line.

Significant Factors:

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

1. The pilot had forgotten about the spur line to the homestead.

The pilot was on the final leg of a competition gliding exercise, when deteriorating lift made an outlanding necessary. Final approach to the selected paddock was into a 10 to 15 knot wind, but was also towards the setting sun. The pilot had difficulty in seeing ahead because of the sun glare, which was exaggerated by a thin film of dust on the canopy. The pilot failed to see powerlines ahead of the aircraft. Following collision with the wires, the aircraft struck the ground heavily. This accident was not the subject of an on scene investigation.

The pilot elected to conduct the flight at a very low height above the ground. The aircraft collided with power lines, which severed the top 10 centimetres of the rudder. Control of the aircraft was maintained and a safe landing was made at the intended destination.

Circumstances:

At a height of about 30 feet after take-off the aircraft struck a power line, nosed over, and impacted the ground tail first. The pilot had not been aware of the power line which was difficult to see.

The pilot was conducting a soaring flight when deteriorating lift conditions made an outlanding necessary. A paddock was chosen and the pilot carried out a standard approach pattern, aiming to land into wind. He noted a powerline pole on a hill some 500 metres away, but could not see any other poles near the intended landing area. However, as he was about to turn onto final approach, he noticed a single powerline directly ahead of the aircraft. There was insufficient time available to take any avoiding action, and the wire struck the aircraft canopy. The aircraft subsequently impacted the ground and cartwheeled to a stop 87 metres beyond the point of collision with the wire. The powerline struck by the glider was particularly difficult to see from the air. The pole on the hill was prominent, but the other pole was situated amidst a group of farm buildings. The distance between the poles was one kilometre. The pilot had been at a lower height than normal for a turn onto final approach, however there was little doubt that the intended landing would have been successful had the wire been avoided.

The pilot had been soaring in wave conditions, when sink was encountered and an outlanding became necessary. The field initially selected was obstructed by a power line and the pilot manoeuvred towards another area. On late final approach the aircraft collided with a single strand power line and subsequently struck the ground heavily. The pilot later advised that he had seen a pole supporting the line but had thought it was aligned in another direction. The large distance between the poles supporting the power line reduced the possibility of the pilot being able to accurately assess the direction of the line.

On 20 January 2011, a Pacific Aerospace Corporation Cresco 08-600 aircraft, registered VH-KPY, was conducting a low level survey flight in the vicinity of Bingara, New South Wales.

The survey flight was conducted at 130 ft above ground level. During the fourth survey line the aircraft struck a powerline. The powerline was strung between two hilltops about 1,000 m apart at a height of 130 ft.

Following the collision with the powerline, the pilot noticed the wing skin was torn and he experienced some difficulties in controlling the aircraft.

The pilot elected to conduct a forced landing. During the landing the right wing collided with a hay bale. The pilot was not injured.

As a result of this accident, the aircraft operator intends to contact the power authority in each state to request the location of powerlines which they will overlay onto their Google Earth and topographic plans. It is proposed that this will occur on all surveying flights that present a risk.

The operator is also considering increasing the minimum height at which a survey can be conducted. If lower survey heights are required, and assessed to be suitable, they will be conducted by more experienced flight crew.