The helicopter is carrying out survey work as part of Meridian Energy Ltd's investigations into its proposed north bank tunnel power scheme.
The Heliworks Queenstown Helicopters' Squirrel B2 is flying out of the Omarama airfield with electro-magnetic survey equipment slung beneath it to perform a geophysical survey of the power scheme site on the north bank of the lower Waitaki River, from the Waitaki dam to the Stonewall, west of Ikawai.
Meridian's $900 million proposal is to excavate a 34km-long tunnel which would have one powerhouse producing between 1100GWh and 1300GWh of electricity a year.
The scheme would use up to 260cumecs of water from above the Waitaki dam.
Meridian external relations manager Claire Shaw said the survey equipment, from Canada, was already in New Zealand so Meridian had decided to make use of it.
The same equipment was used last year for about six days, to perform an initial survey testing to see what further information was needed.
This time, flying about 60m above the ground, it is gathering more detailed information as Meridian considers the design of the scheme.
"It is a feasibility study that will provide valuable information to assist in the engineering investigation phase of the project," she said.
The survey is looking at the ground structure, up to 100m deep, along the route of the proposed power scheme.
It will help identify drilling sites which need further investigation.
Last week, four days of surveying were done, and five or six more would be needed to complete the survey, she said.
The equipment has already been used by other companies, including Glass Earth, for their own geophysical surveys.
