Eyewitnesses to the skydiver plane crash that killed nine people have told an inquest they don't agree with some of the findings of the crash investigators.
Nine died when their plane plunged into the ground soon after takeoff at Fox Glacier nearly two years ago.
Oliver Mason, who watched as the plane came down close to where it had taken off, told the hearing he attempted to provide a statement to police soon afterwards.
He was told they'd already taken a lot of statements and was asked if what he had to say was any different.
Mr Mason disputed the finding by transport accident investigators that the plane was almost vertical on take-off.
Another witness, Dr David Baldwin, who was at the airstrip giving pilots their medical check-ups was also never interviewed and says he's angry about that.
He also disagrees that the aircraft came down in a vertical position and says it was a cloudy day, not a clear day as the investigators said.
Mother tells inquest CAA chief has questions to answer
The mother of one of those who died in the crash wants the head of the Civil Aviation Authority to appear at the inquest into the incident to answer questions and if necessary resign.
The CAA has already been criticised by a Transport Accident Investigation Commission report for a lack of oversight of the modifications made to aircraft used by skydiving companies.
Pamela Bennett, whose son Adam was among the dead, says the CAA needs to take a more hands on role to ensure the rules it hands down are actually being applied.
Mrs Bennett says its chief executive Graeme Harris needs to be held accountable, apologise for any mistakes made and, if necessary, resign.
She is angry the CAA appears to be ducking for cover over its failure to properly monitor the skydiving industry.
Inquest hears case for and against seatbelts
The need for skydivers to wear seatbelts when their aircraft takes off has been challenged at the inquest.
An aviation specialist, Barry Payne, has recommended seatbelts to prevent those on board from tipping the aircraft off balance.
Seatbelts were not required at the time of the crash and on Tuesday the Civil Aviation Authority's lawyer, Duncan Ferrier, said that was because parachutes could deploy inside the aircraft as skydivers attached and detached themselves.
Mr Ferrier said that could have led to skydivers being sucked out of the plane's open door or even to the aircraft being pulled out of control.
Mr Payne maintained that the risks associated with not wearing seatbelts outweighed those of wearing them.
Witness Oliver Mason saw the crash from the airstrip and described to the inquest the moment soon after take-off when he realised something was not right.
He said that, even after two years, the incident is like a video playing over and over in his head.