Nelson bush fire: Pilots perform a carefully choreographed dance in the skies to keep flames in check
Saturday, 9 February 2019
In the smoke filled skies of Nelson, helicopters and planes are performing a choreographed dance while attacking the Pigeon Valley fire from above.
Aircraft have descended on Nelson from all over the country, fighting the blaze with buckets in tow since Tuesday afternoon.
For the pilots battling the blaze, it's just part of the job.
The pilots remain in constant radio contact with each other, each knowing the next move of every chopper.
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'Everybody looks out for everybody,' Nelson Marlborough Rescue Helicopter pilot Barry McAuliffe said.
'Most of the guys know each other within the industry.
'You know who you're following and you stay in that sequence the whole time.'
The helicopters dump more than 500 litres of water from their bucket.
Most carry 800 to 1000 litres of water per sortie.
Watching the helicopters release the water over the raging fires, some might wonder how the sprinkle could effect a towering inferno.
Aerial fire-fighting foam is pumped into the buckets, making the water more effective and stopping it from evaporating through the heat of the fire.
Longlines dangle the water buckets 100 to 150 feet below the choppers to keep them away from the debris, trees and smoke.
And how the water attack is approached depends on where it is, McAuliffe said.
'If it's an open grassy area, you do a running drop, keeping moving as we release the water to make the drop spread more and disperse it to a finer mist which is quite effective on the grass areas.'
Water is taken from forestry or farming dams, and fire crews refill the dams that are deep enough for the choppers to take water from easily.
The helicopters are given direction on which areas of fire to target from a smaller machine observing from above.
It hosts a Fire and Emergency New Zealand (FENZ) air attack supervisor.
McAuliffe said the FENZ supervisor had a better view of the overall picture while the water-dropping helicopters focused on their areas.
The pilots warn each other of wires to look out for, the best water spots, and flying conditions around certain areas.
Most of the water has been taken from forestry and farming dams with 'the better ones' being refilled by the ground fire crew.
Fire and Emergency incident controller John Sutton said special trucks with deep containers were brought in on Friday for helicopters to dip their buckets into.
He said there were no concerns of running out of water.
'We'd use salt water if it was close enough.'
The helicopters go back and forth a number of times, dunking their buckets and emptying them on the fire, before they are forced to land and refuel.
Their fuel lasts about an hour.
'The guys are generally rostered in and out to manage fatigue.'
Unlike the ground crew who have been working through the night, the pilots have limited visibility at night through the smoke and most of the choppers aren't compatible with night vision goggles.
'We're all experienced pilots and we know what our limits are. There are times where it's not safe to be in an area so we shift; could be due to visibility, wind conditions, could be due to any number of hazards, but it's all just managed.'