On the morning of 7 February 2004, the pilot of a Piper Aircraft
Corporation PA-28R-200 Arrow, VH-TRZ, conducted a private
sightseeing flight over Lake Eildon in Victoria with three
passengers onboard. At about 1135 ESuT, witnesses observed the
aircraft strike a power cable over the lake. The cable was one of a
group of six cables that formed a power line linking Kiewa in
north-east Victoria to Melbourne. Each cable was 30.8 mm in
diameter, and transmitted 220,000 volts of electricity. The power
line was depicted on the Melbourne World Aeronautical Chart, and
spanned Lake Eildon between Mt Enterprise and Mount Pinniger. The
power line was not fitted with marker devices, and nor was it
required to be. The span was 2,222 m in length, and the northern
and southern support towers were respectively 1,076 ft and 781 ft
above the water level of the lake. The aircraft struck the power
cable at about the lowest point of the span, which was about 133 ft
above the water level of Lake Eildon. The water level of the lake
was 266.53 m above Australian Height Datum on the day of the
accident. That was equivalent to 875 ft above mean sea level
(AMSL).
The aircraft approached the power line in a south-easterly
direction, and the sun's position and elevation at the time were
unlikely to have caused the pilot difficulty in observing the
cables, which lay at right angles to the aircraft's flight path.
Witnesses who observed the aircraft before it struck the cable
reported the aircraft had appeared to be operating normally. A
number of those witnesses reported that their attention had been
drawn to the aircraft because of its low height above the surface
of the lake.
The force of the wirestrike dislodged the left wing of the
aircraft, and the aircraft descended out of control and impacted
the water about 165 m beyond and to the southeast of the cable that
was struck. The aircraft was substantially destroyed because of the
wirestrike and the subsequent impact with the water. The four
aircraft occupants were fatally injured by impact forces when the
aircraft impacted the water. The body of the pilot was not
located.
The aircraft had valid certificates of registration and
airworthiness. The pilot held a Private Pilot (Aeroplane) Licence
and was endorsed to fly the aircraft type. He held a current Class
2 medical certificate. The pilot required vision correction, and
his wife reported that he was wearing contact lenses on the day of
the accident. There were no known physiological or psychological
factors that may have affected the pilot's performance.
There was no evidence that environmental, mechanical,
operational or other factors contributed to the circumstances of
the accident.
Civil Aviation Regulations specify that an aircraft, when not
flying over a city, town or populous area, must not fly lower than
500 ft above the highest point of the terrain, and any object on
it, within a radius of 600 metres. The aircraft therefore should
not have been flown at a height of 133 ft over the surface of the
lake. The investigation could not determine why the pilot descended
the aircraft to an unsafe height.