Fire crews may be back on Mt Alpha near Wanaka for the sixth day today, dampening down remaining hot spots from the fire that started on Wednesday afternoon and burnt almost 200ha of hillside pasture.
Fire Service southern communications shift manager Andrew Norris said three ground fire crews and a helicopter with a monsoon bucket were working on hot spots on the blackened hillside on Saturday and most of yesterday, during daylight hours.
The fire, which began just after 3pm on Wednesday, burnt 199ha of grass and heather on Hillend high country station. Principal rural fire officer Graeme Still described the fire as "very deep-seated" and predicted it would be several days before it was completely out.
Volunteer fire crews from around the Central Lakes district, Southland and Mount Cook, together with helicopters from several different companies were brought in to fight the blaze.
On Wednesday afternoon, and all through the daylight hours of Thursday, eight helicopters carried water from Lake Wanaka in monsoon buckets to the fire on Mt Alpha.
Alpine Helicopter director and general manager Nick Wallis said the conditions were "challenging" but it was perfectly safe.
"We had plenty of breaks, everyone subbed in and out, and fatigue was managed really well."
He said as well as the eight helicopters with monsoon buckets the rural fire service had a fire officer in a helicopter called "a bird dog" and it was his job to manage the air operations.
"The fire officer was managing where we were flying, what we were working on, and making sure there were no potential cross-overs, plus all the helicopter pilots were talking to each other as well, so although it it looks like organised chaos it was actually really well synchronised," Mr Wallis said.
Mr Wallis said one of the biggest dangers the pilots faced was when a member of the public spotted a drone on Wednesday night and all the helicopters were grounded until it was removed.
"The public need to be aware that helicopter pilots cannot see drones in the air. They blend into the mountains."
"They are a risk to safety and they were a risk for the properties around the fire as we couldn't fight the fire for a time and it could have got out of control, so when there are helicopters or aircraft in the air keep drones away," he said.
Mr Wallis said fighting fires such as the one on Mt Alpha "was not something they do a lot of" but it was something for which the pilots trained.