A helicopter that was helping to install a Christmas tree in Auckland crashed to the floor in dramatic fashion after colliding with scaffolding.

Greg Gribble who has over 20-years flight experience was flung out the front door of the chopper before falling back in through its side door.

Some experts have claimed it was in fact the cables running from the scaffolding that was what the blades of the helicopter got caught up in, which resulted in the horrifying crash.

"There's certainly some clues that lead us to believe there was an issue with the cable that was being used and that it interfered with the helicopter," said Steve Walker who is the safety investigator for the Civil Aviation Authority. "[The pilot] was lucky to walk away from this."

The footage captured by TVNZ (TV New Zealand) shows Gribble narrowly missing the blades which are still rotating, which would have killed him instantly.

Richard, who witnessed the crash, told the AP: "he scary thing was actually seeing everyone on the ground running for their lives."

"People started running away and then they started running back."

The pilot was helping install a seven-storey fibre optic Christmas tree in Auckland and family members have told the press how lucky he is to be alive.

Ms Gribble, Greg's daughter, who runs the family business "Helisik Helicopters" and is nine months pregnant with her first baby said: "I know that he's walked away, I know that he's on his way to Auckland Hospital."

"I'd say he's very, very lucky to walk away."

Son, Jaz Gribble who is also a pilot was shocked when he found out about his fathers' lucky escape. "Someone must have been looking out for him. That's all we could have prayed for - that he's safe and happy. Someone must have been on his side," he said.

"He's my dad, so it's a little close to the bone for a start. This has shaken me."