All mast-bump accidents in New Zealand in the past 10 years and all fatal mast-bump crashes in the past 25 years involved Robinson helicopters, according to Civil Aviation Authority data. They are almost always catastrophic.
This week the Transport Accident Investigation Commission released a report blaming mast-bumping for a helicopter crash which claimed the life of Damian Webster, 37, whose Robinson R44 went down northeast of Mt Arthur, in the Kahurangi National Park, in 2014.
The Robinson Helicopter Company said it disagreed with much of the report including the findings and technical background.
Meanwhile, a separate investigation is under way into the death of Noel Wilson, 51, who died on Monday when his Robinson R22 crashed near Reefton on Monday.
Patterson's Eye in the Sky device aims to provide more information about the causes of such accidents.
Helicopters do not routinely have data recorders but miniaturisation now makes them practical. It is hoped such devices will close the gap in knowledge about the causes of these types of accidents.
Investigations of these types of crashes commonly state that they occurred for "undetermined reasons".
New Zealand's Transport Accident Investigation Commission last October put Robinson helicopters on its watchlist - the highest warning it can give.
Patterson welcomed the decision in a statement at the time. "I have suffered the ultimate loss and don't want others to suffer."
She said crash data indicated Robinson helicopters had "a disproportionate accident and kill rate around the world, not just in New Zealand".
Patterson last month showed the Eye In The Sky at an international aviation conference in the United States. It records video, audio, speed, altitude, position and information about pitch, roll and yaw.
Profits go to the James PG Foundation, named for her son.
The Robinson Helicopter Company, based in California, is also working on a data recorder of its own.
Kurt Robinson, chairman and chief executive, told the Weekend Herald the company had developed an autopilot.
"A data recorder will show what went wrong," Robinson said. "An autopilot will hopefully prevent the accident from occurring."
In turbulence, which is thought to be a factor in mast-bump accidents, a pilot could take their hands off the controls and let the autopilot take over.
"There are things like that coming along that I think are going to advance safety, and at the end of the day that is what it is all about."
Robinson told the Weekend Herald his company's helicopters were safe so long as they were handled correctly and in suitable conditions.
"We look at every single accident. And that thought is always foremost in our minds."
Safety was a priority for the company, including looking at what it could to "prevent accidents" he said.
"I fly with my wife, my kids all the time. My engineers fly."
