Wirestrike involving Hughes 269 C, VH-KHO, Green Vale' Barellan, New South Wales, on 23 October 1990

Circumstances:

The aircraft was carrying out a short familiarisation flight before beginning the day's powerline inspection program. On board were the pilot and the owner of the property being used as a temporary base for operations. The aircraft took off toward the east over a flat paddock, the pilot's intention being to turn north from a point near the centre of the paddock then to intercept an east-west powerline and to follow that line westwards. While still tracking east, at about 20 feet altitude, the aircraft struck and snapped a north-south powerline crossing the take-off path. The aircraft then continued forward for about 60 metres before impacting the ground and coming to rest five metres beyond the impact point. An eyewitness to the accident stated that he was 'almost certain' that he had informed the pilot of the existence of the north-south powerline when the aircraft had first arrived at the property, seven days before the accident. The pilot stated that he had no prior knowledge of the line. The aircraft had taken off from the pad at least three times and had landed at the pad at least four times since first arrival. All prior movements had been to the west of the pad, and the pilot had not been reminded about the line. Prior to take-off on the day of the accident, the pilot briefed the passenger about the proposed profile of the flight and asked the passenger for any comments. The passenger agreed with the proposed profile but did not mention the north-south powerline. The pilot looked to the east to note any obstructions but did not see the line which was very difficult to see from the take-off point. In addition, due to the relatively low position of the sun in the north-eastern sky, glare may have adversely affected his vision. Further, the flat, open terrain did not provide any visual cues to alert him to the requirement for obstruction clearance. However, the pilot did not closely inspect the take-off path from the ground. Examination of the wreckage did not reveal any defects in the aircraft which may have contributed to the accident. The performance capability of the aircraft was such that the climb gradient required to clear the powerline could have been easily achieved.

Significant Factors:

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

1. The pilot did not closely inspect the proposed DEPARTURE path for obstructions prior to take-off.

2. The line was very difficult to see from the take-off point. Glare may have aggravated this problem.

3. The flat, open terrain, without obvious obstructions along the take-off path, provided no cues alerting the pilot to the need for obstruction clearance.