"It was one of those situations you'd never expect to face" but "instinct" and "character" got Kāhu NZ helicopters' staff through.
That's according to Lachie Storey, the "extremely proud" father of 28-year-old pilot Tom Storey.
Tom was a passenger in an aircraft flown by his colleague Jason Hill.
Kāhu NZ chief executive Mark Law flew a second helicopter out with his two staff, as soon as they heard of the dire situation after the Whakaari / White Island eruption on Monday afternoon.
Together they spent 40 to 50 minutes on the island almost 50km from shore.
The trio brought 10 survivors back to land so they could be transferred to specialist burns units.
Among those Storey assessed at the scene was "his mate Hayden [Marshall-Inman]" who could not be saved.
Forty-seven people were on the island when the first eruption began at 2.11pm on Monday.
Six are confirmed dead, eight are missing (presumed dead) and 30 are in hospital.
The other three have been discharged.
'Great tragedy' - volcano spurting 15m mud days before eruption
Business pioneer and ex-Whakatāne councillor dies
• White Island volcano erupts in Bay of Plenty: six dead, eight missing, 30 in hospital
• White Island eruption: Sixth person confirmed dead
• Scientist: White Island eruption was 'basically instantaneous'
Tom is now on standby to return to the island to help recover bodies.
He runs his own building business alongside flying for Kāhu.
He downed his tools immediately when he knew he could help.
"He just happened to be working at Coastlands which is just five minutes from the airport [where Kāhu Helicopters is based]," Lachie Storey said this morning.
At that time rescue helicopters were not prepared to land at the scene, but some private businesses such as Kāhu were.
Lachie said the staff did the right thing despite the danger.
"They are extremely accomplished pilots. They do risk assessments and it wasn't just a case of flying in there and hoping.
"They were very, very sure that they could save lives, which they did. They didn't go in blind and boy did they help some people.
"To me, they are heroes in the true sense ... They went far beyond what could be expected of anyone."
He wasn't aware his son was flying to the scene until an hour after the eruption but "immediately backed him".
He described Tom as "a very special person" and "a fine young man".
"Tom is a man who will help any other person. It was exactly his character to do it ... He did what he could and that's all you can ask of anybody."
Lachie himself has search and rescue experience and said hearing the helicopters arriving would have comforted victims.
"It was still pretty dusty and dark. That sound alone would have been a huge relief for those who were in that state of being able to comprehend what was happening."
He said his son Tom left school at age 16 and started a building apprenticeship.
Tom was third in the national Master Builders Apprentice of the Year competition in 2011.
A year after he started his own business and "went hard with it" to earn enough money to fund his helicopter pilot training.
"He is an extremely good builder, very much into attentive to detail, but he'd always wanted to fly choppers," Lachie said.
"He has just got an absolute passion for flying and I think if you love doing something you've really got to make sure you give it a go.
Tom now juggles the two roles, doing evening and early morning flights, many of which are to White Island.
Clarke Gayford, the partner of Prime Minister Jacinda Ardern, wrote about visiting White Island during a tour with Tom Storey earlier this year.
Lachie sat down with Tom last night to talk about his welfare after witnessing the "nature of the injuries" and the "traumatic environment".
"He is really comfortable with what he did ... I've made sure that he talks to the right people. I believe Tom is more than capable of handling it.
"He is very level-headed and calculated and knows his own mental state extremely well."
Lachie said Kāhu staff had taken part in "constant debriefs, many with police".
Lachie and Tom's mother Karen have been taking "constant" calls from proud friends and family "right to his [Tom's] first college teachers from way back".
Earlier, Mark Law told the United Kingdom's Guardian newspaper: "We found people dead, dying and alive but in various states of unconsciousness."
He said he had seen many dead bodies when working overseas in war zones but was still shaken by the severity of the injuries.
"A lot of the people could not talk. It was pretty quiet. The only real words were things like, 'help'. They were covered in ash and dust. We were picking them up and skin was coming off in our hands."
"I descended down into the crater, down to 200ft," Law said.
"We could see people very easily from the air. They were lying down or spread-eagled. We were looking for somewhere we could land that would not be a big problem. The dust is very acidic and that's not good for the engines.
"We both landed in the centre of the island where we felt it was okay. It was ashing but we could deal with it. We went to assess everyone. We were moving around tending to people who were in real distress. We wanted to reassure them."
He said, "it felt like running through talcum powder."
"It was very hard to breathe and without a gas mask we were gasping for air, but … adrenaline takes over. I'd rather break a few rules and save some lives than sit here wondering what we could have done."