"You hear stories about your life flashing before your eyes ... it's just disbelief ... and time just really slowed down," Sedon told the Herald on Sunday. "My recollection was everything was slow ... we had gone further before we hit the mountain so time definitely slowed down ... it was horror and disbelief at what you were seeing."
Sedon said he now questioned how he had managed to survive the crash, adding he felt grateful and lucky. That sentiment was often mentioned in several conversations he had with fellow survivors in the weeks after the tragedy.
"When you look at it and you think about it, you don't read many headlines of how a helicopter crashes into the mountain and there are six survivors," he said.
"One of the survivors called me the other day. We talked for a while and we just can't believe that we are alive." Mentally each week he had been "celebrating" his miracle survival.
"It's a miracle that any of us survived when you look at the crash."
Seven people were aboard the Helicopter Line/Harris Mountains Heli-Ski chopper on the fateful day.
The five tourists, including Box, were part of a church group from Auckland.
In the minutes leading up to the fatal crash Sedon said the heli-skiers were "really happy ... buzzing".
"You could hear them [yelling], 'Yeeha' and 'Wahoo'. They were having the time of their lives," he said.
But that joy soon became a nightmare for the touring party when the Squirrel AS350 B2 crashed high up Mt Alta.
"I just saw the ground coming and only had time to register in my head that something was wrong -- then we hit," he said.
"I remember I closed my eyes and then we sort of exploded into the ground.
"It was really violent ... you don't really get much time to think but you are pretty sure it's going to end any second.
"Then I felt myself tumbling head to foot, head to foot outside the helicopter. I was flying down the mountain at 100 to 200 metres sort of head to foot."
Sedon came to a sudden halt in the snow, dazed and in agony, on his hands and knees.
"One of my eyes was closed from the impact and I was covered in fuel so the first thing was to see if there was anything burning."
Defying the pain barrier, and struggling to breathe, Sedon managed to make contact with emergency services and direct them to the scene of the mountainside carnage.
Rescuers, including a group of skiing guides, arrived on the scene about 15 minutes after Sedon called for help.
Box had been sitting at the back of the helicopter when it crashed.
It is understood the 52-year-old had been given cardio-pulmonary resuscitation (CPR) by members of the skiing group and then the first rescuers on the scene.
Skyline Enterprises, which owns The Helicopter Line, has been actively fundraising for Box's family, Sedon revealing he had "donated some of my wages" to the cause.
The crash is the subject of at least two independent investigations.
The Civil Aviation Authority confirmed last week it had commenced a health and safety inquiry, and the Transport Accident Investigation Commission is also investigating.
