THE pilot of a helicopter which crashed, killing a Dundee boy, walked free from court yesterday when the case against him collapsed.

As the angry family of nine-year-old Garry Malley left the courtroom, they threatened to take out a private prosecution against Mr Robert Hobson. The Crown Office said Crown Counsel were considering having the sheriff's decision reviewed at the High Court of Justiciary.

Sheriff James Scott ruled there was no case to answer against 56-year-old Mr Hobson because of a lack of corroborative evidence. He had been accused of negligence.

Garry died instantly from head injuries in the crash last July at Glamis Castle, Angus. He had been taking his first helicopter ride at an event involving Noel Edmonds' charity, the Airborne Trust. Four other special needs youngsters were injured.

The pilot, from Penicuik, Midlothian, had been accused of putting passengers at risk by taking off with misted windows and flying the helicopter with restricted visibility. A second charge alleging he had six passengers on board when he was licensed for only five had been dropped on Tuesday.

Defence counsel Michael Jones QC told Sheriff Scott there had been no corroborative evidence the pilot's visibility had been restricted.

Several witnesses had said they could not see into the helicopter during take-off but they did not specify this was because of misted windscreens, he said.

Garry's father, Mr Thomas Simpson, ran from the courtroom, followed by the boy's mother, Ms Sandra Malley, who shouted abuse at the pilot.

Outside the court, Mr Simpson said he would try to take out a private prosecution.

He added: ''This is rubbish, it is all wrong. I do not understand what they have done. There will be an appeal going in as soon as possible. As far as I'm concerned, they should never have gone up in it in the first place.

''This has been the worst year of my life. If they think this is the end of it, they can think again.''

Later, Mr Simpson, a loader at a supermarket, spoke of the agony of the past year and the stress which had cost him his 12-year relationship with Garry's mother.

He said: ''I didn't want him to make that last journey without me. All I remember is going to the funeral and wishing I was being laid in the ground beside him.''

Mrs Malley said she had been on medication to help her sleep because every time she closed her eyes she saw Garry's face as he walked to the helicopter. She added that it had ''ruined my life''.

A spokesman for the Crown Office said any review of the case would not affect the acquittal of Mr Hobson but could ''provide guidance for future cases''.

He said: ''In a jury trial, the sheriff's decision is final and his decision to bring the prosecution to an end cannot be reversed. However, Crown Counsel are considering whether it is appropriate to have the sheriff's decision in law reviewed.''

He said a copy of the sheriff's decision had been forwarded by the procurator-fiscal to Crown Counsel.

A spokesman for the Airborne Trust said the collapse of the trial was an unsatisfactory result.

''This is a confusing outcome which does nothing to answer many of the questions which Garry's family and the team at Airborne are desperate to have answered,'' he said. ''This remains a tragedy and every day that goes by throws up new hurt and new questions.''

A spokesman for Kwik-Fit, which owned the Bell Jet Ranger helicopter involved in the crash, said: ''This was a tragic accident and everyone involved has suffered a great deal of anguish, but we have nothing to say about the legal proceedings.''