Chopper crash investigation
■ Australian Transport Safety Bureau says pilot didn’t have access to maps
LAST week the Australian Transport Safety Bureau (ATSB) presented its investigation into the helicopter accident in Piries in July, the second helicopter crash in the area just this year.
The report found that the pilot completed all preparations possible before the flight and that similar incidents had happened nearby in the past.
On July 6, police and emergency services attended a call to Mansfield-Woods Point Road, Piries, on Saturday afternoon, after a helicopter crashed on a private property just after 3pm.
A Robinson R44 helicopter, along with a pilot and passenger, struck a powerline before colliding with the ground on a private flight from a property near Mansfield.
A male and female in their 40s were on board and treated at the scene before being airlifted to hospital.
The female received serious injuries while the male received minor injuries.
An investigation into the incident was then immediately enacted.
The new report highlights a lack of electricity network maps available for pilots, saying that before the flight, the pilot had indeed sought and obtained some information about hazards, including powerlines, from the property owner.
However, the owner was not aware of a distribution powerline strung across the nearby valley with a span of 560 metres, and he could not see the wires from his property.
It was also discovered that this was not the first time this particular power line had been hit by aircraft.
The wires did not have aircraft markers, though the Australian Standard (AS 3891) does not require marking.
Unlike some other states, readily usable Victorian electricity network maps were not available to assist the pilot’s planning.
As a result, it is believed the pilot’s pre-flight planning did not identify the powerline, which the helicopter struck 48 metres above the ground, shortly after take-off.
The helicopter descended rapidly, travelling about 400 metres after the wire strike before colliding with the ground in an upright position, and rolling over, resulting in serious injuries to the passenger and minor injuries to the pilot.
“In Victoria, electricity network information is not readily available to aid pilots during the flight-planning process,” ATSB director of transport safety Stuart Macleod said.
“Such information provides valuable safety information to aid pilots in planning flights, and assists the visual identification of hazards, such as wires and poles.”
He also said it is good practice to always maintain a height of at least 500 feet above ground level and that the investigation also highlighted that pilots flying at low level should always be scanning the terrain on either side of their flight path for poles and towers.
But he added that they should avoid low flying at all unless it is necessary.
“The ability of pilots to detect powerlines depends on physical characteristics such as the spacing of power poles, the orientation of the wire, and the effect of weather conditions,” he said.
“Depending on the environmental conditions, powerlines may not be contrasted against the surrounding environment.
“In addition, the size of the wire and limitations of the eye can mean that it is actually impossible to see the wire.
“Therefore, it is good practice to always maintain a height of at least 500 feet above ground level except during take-off and landing.”
After the accident, local landowners advised the ATSB that the powerline was erected in the 1970s, and that an aircraft conducting aerial agriculture had struck it in the 1980s.
They reported that following that past incident, orange plastic marker balls had been fitted to the wires, however, they had perished over time and not been replaced.
“Effective wire avoidance can be achieved using a combination of available wire location information; wire marking; and the avoidance of unnecessary low flying, especially flight below the height of surrounding higher terrain where wire spans may be present,” Mr Macleod reiterated.
The incident was the second of its kind this year in the shire, with four people lucky to walk away from a helicopter crash in January after a landing went wrong on the edge of Lake Eildon, near Howqua Inlet.
Mansfield police and other emergency services were on the scene quickly, where it was reported on arrival that the occupants were out of the cockpit and the chopper itself was lying on its side.
Thankfully, there was no fire present and the four occupants were reported as not sustaining serious injuries.
The ability of pilots to detect powerlines depends on physical characteristics such as the spacing of power poles, the orientation of the wire, and the effect of weather conditions. - ATSB DIRECTOR OF TRANSPORT SAFETY STUART MACLEOD