Background and Pre-Accident Events
The aircraft involved in the accident had experienced delays in servicing and repair, and was only released six weeks prior to the accident. These delays caused the operator/pilot to fall behind in scheduled commitments, and some witnesses reported that the pilot was worried about the situation.
Accident Sequence
On the day of the accident, the pilot had just completed spraying a 243-hectare paddock and landed to reload. After taking off for a new task, the pilot was observed making an aerial inspection of the paddock before entering the first swath run. At the end of this run, the aircraft collided with a Single Wire Earth Return (SWER) powerline and crashed.
Later analysis showed that the aircraft was in a right bank of approximately 18 degrees at the time of impact. The SWER line ran across one end of the paddock at an angle, on the crop side of a windmill just inside the fence bordering a road. The line contacted the right main landing gear and outboard sprayboom attachment struts on the right wing. The wire broke after impact, but the aircraft hit the ground heavily on the right main gear. The gear detached from the aircraft, the propeller struck the ground, and the aircraft slewed around as it came to rest after traveling approximately 27 meters on the ground.
Post-Impact Fire and Fatalities
A fire broke out almost immediately after the aircraft stopped, destroying the front half of the aircraft. The pilot, who was the sole occupant, was killed.
Investigation Findings
The official investigation proposed two main hypotheses. One suggested the pilot may have been distracted from a less demanding task by business worries. The other hypothesized that the pilot perceived the SWER line was on the right of the windmill and outside the fence, and therefore did not consider it an obstacle during the procedure turn. However, neither hypothesis could be substantiated.
An additional concern was raised because the pilot died from impact injuries in an accident that, prima facie, appeared survivable. Investigators questioned whether the pilot had secured the harness properly or whether the inertia reel had failed. Detailed engineering inspection of the inertia reel by the bureau and the manufacturer could not positively determine the mode of operation of the inertia reel. However, the post-mortem report indicated that the nature of the injuries, while sufficient to cause death prior to the fire, suggested the inertia reel had probably not failed. The pilot did not see the powerline in time to avoid the collision.