Wilderness advocates have urged the West Coast Conservation Board to stand up for the rights of people to experience the backcountry without seeing or hearing aircraft overhead.
Federated Mountain Clubs president Jan Finlayson has written to the board asking it to challenge the Department of Conservation's "laissez-faire" stance on allowing flights over the Adams Wilderness Area and other gazetted wilderness areas on the Coast.
The western South Island contains five of New Zealand's gazetted wilderness areas - Tasman, Paparoa, Adams, Hooker/Landsborough and Olivine.
"The expansion of low-altitude scenic flights into wilderness areas is currently threatening the natural quiet and wilderness values of the Adams Wilderness Area," Finlayson said.
"It is critical that DOC intervenes early before these companies become both financially and culturally entrenched."
Until relatively recently, scenic helicopter flights on the West Coast had operated almost exclusively in the Westland Tai Poutini National Park, with overflights and landings at Fox and Franz Josef glaciers.
"However, the allure of pristine wilderness has drawn helicopter operators to offer low-altitude scenic overflights of the Adams Wilderness Area," she said.
She referred to advertisements by local helicopter companies inviting customers to fly over the "stunning" snowfields of the Garden of Eden and Garden of Allah wilderness areas.
DOC's "inaction" was inconsistent with its statutory responsibility, Finlayson said.
The department was supposed to work with aviation authorities to prevent the adverse effects of overflights on national park values, including the enjoyment of people on the ground.
"A defining aspect of wilderness is natural quiet - a soundscape free from man-made noise. Today our national parks and other protected lands grow busier and busier.
"It's often hard to get away from other people or the distant hum of aircraft and vehicles. In contrast (even to national parks) wilderness areas offer wildlife and humans alike, a quiet refuge."
In the statutory description, wilderness areas are places where people are unlikely to encounter other users or find evidence of others having been there; there is no mechanical access; no tracks, bridges or huts; and there is no noise intrusion from aircraft.
Finlayson said DOC could seek to restrict the low-level flights through liaison with aircraft operators and advocacy to other agencies, to protect the opportunity for recreationalists to experience the natural quiet and natural character of these areas.
"The writer regrets the degradation of natural quiet in the Adams Wilderness Area... until now, the tourism and aviation industry on the Coast has respected wilderness areas and the situation was balanced, with large swathes of Westland Tai Poutini National Park sacrificed for scenic flights and the nearby Adams Wilderness Area free from intrusive noise.
"The relatively new practice of low-altitude wilderness area overflights threatens to destroy the very quality that attracts people."
Precision Helicopters director Matt Newton, who flies over the Adams Wilderness Area, said several of his customers were Federated Mountain Club members wanting to be dropped off at huts.
"If I spot a climber I give them a wide berth, and we have agreements with DOC about flight paths, so we don't disturb walkers doing the track, or the neighbours... if it wasn't for the helicopters most older people would never get to see this most beautiful part of the Southern Alps."
Business had been brisk over winter, Newton said.
"It's all the boomers... they can't go to Rarotonga or wherever for a holiday so they have been coming down and taking the flight... also families. If you couldn't fly over, you would have to be some sort of elite mountain climber to ever see a wilderness area. Is that fair?"
He had initially applied to land on DOC stewardship land at Feather Flat hot pools and Ivory Lake, but after an objection to that from people saying they were special places, he changed his application, he said.
"That was fair enough and I took that on board, and rewrote my plan - and it was approved. I haven't had a single complaint about noise or anything else since we set up last year," Mr Newton said.
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