These never-before-seen pictures show danger man Zak tiptoeing along at the peak of Germany's highest mountain - the colossal 1,746m Zugspitze.
And if that isn't terrifying enough - he even completed a 10-metre section of the crossing without a safety line.
Highlining requires nerves even more steely than tight-roping because participants take their precarious steps along a loosely anchored strip instead of a rope made rigid through tension.
It means the highline will bounce and wobble as they shift their weight taking each measured step.
Heinz walked three knee-trembling sections at the Zugspitze in turn, covering a total of 70 metres.
'A highline had never been attempted before at the Zugspitze and I wanted to conquer it,' he said.
'It was difficult to complete all three stages as the area is very exposed to wind. This made the middle section with no safety line more challenging.'We had to keep coming back over several days to weigh up if we could attempt each section.'
For the past eight years Heinz has toured the world looking for the perfect spots to practise his art.
Today he is regarded as a pioneer who led the sport's development and currently booming growth in Europe.
But defying anyone who thinks he's just another stuntman looking for the next rush, the daredevil, from the Austrian town of Scharnitz, oddly said it's all about finding peace and 'losing himself'.
'What I do is not about adrenaline,' he said. 'Walking a highline is my way. It's just what I do.'
To achieve his miracles at dizzying altitudes, Heinz puts all his faith in equipment that includes the one-inch polyester line.
'One problem is that when it is taut and taking my weight, the slightest snag on a rock could break the line," he says.
Super-fit Heinz stays in perfect shape but it's days of mental preparation he values the most.
Like a bobsleigh pilot who must know every twist and turn on his track to avoid death, Heinz runs through each attempt repeatedly in his mind before stepping out.
'When I attempt a walk at the edge of my limits I just have to think it through over and over before I I go up,' he said.
'You have to see yourself taking each step and reaching the end.'
