AN AIR accident investigator has said there is no evidence of sabotage behind the helicopter crash that killed a millionaire Dorset businessman and his pilot.

Conspiracy theories abounded after Stephen Curtis, 45, and his pilot Max Radford, 34, died in the crash near Bournemouth Airport in March 2004.

An inquest jury had been told by East Dorset coroner Sheriff Payne that the story had "all the ingredients of an espionage thriller".

Mr Curtis, a tax exile who owned a castle in Portland, was chief executive of Menatep, a company owned by Russian oil giant Yukos. His uncle, Eric Jenkins, told jurors that Mr Curtis had spoken of receiving threats.

Max Radford ran Red Aviation, based at Bournemouth Airport, as well as piloting Mr Curtis's private Agusta 109E helicopter. His father, Dennis Radford, had claimed security at the airport was "non-existent" and the possibility of sabotage should be investigated.

But Paul Hannant, senior inspector of air accidents for the Air Accidents Investigation Branch, said he had found no evidence of sabotage.

"I do understand the workings of a helicopter and if the helicopter had been interfered with, there would be a very limited number of areas where such evidence would be available," he said.

Nicola Hartford-Bell, legal representative for the Radford family, asked Mr Hannant: "Can you rule out the possibility that there was a device on the aircraft which was remotely set off?"

He replied: "I don't see any evidence of that."

He added: "I don't think I could rule it out with 100 per cent certainty but it would be such a small possibility, 0.01 per cent."

The jury was played a recording of Mr Radford's conversation with Bournemouth Airport air traffic controller Kirsty Haltham just before the crash, which happened at 7.39pm on March 3.

Mr Radford was heard confirming he had a problem before saying "Yeah, we've got power." Shortly before the crash, he said: "Okay, it's okay. I need a climb, I need a climb."

Mr Hannant said the weather was worsening as the helicopter approached Bournemouth. "The pilot would have been operating in a seriously degraded visual environment during the late stages of his approach," he said.

A noise heard on the tape had been identified as a horn warning the pilot that the speed of the rotors had dropped.

"The noise of the main rotor blades can be heard in the background which indicates the aircraft was manoeuvring in tight turns or attempting to turn out of a dive," said Mr Hannant.

"It's clear the pilot was working hard to restore the aircraft to a safe flight path but he was overloaded and may have become disorientated."

The inquest had heard from Red Aviation's operations manager, Lindsey Muirhead, that Mr Radford could have felt under pressure to fly Mr Curtis to his destinations in bad weather.

But Mr Hannant said the pilot had sometimes refused to fly Mr Curtis. On New Year's Eve, when Mr Curtis had hosted a big party at his Portland home and wanted to fly guests there in his new helicopter, Mr Radford had decided the weather was too bad.

"Lindsay Muirhead is right he probably felt morally obliged to fly but if he had recognised the weather was going to deteriorate to this extent, then I would suggest he probably would have said it's not going to be good enough," he added.

The inquest also heard from aviation psychologist John Chappelow how pilots could become disorientated when they could not see the horizon.

"If you remove visual skills from the pilot then you will lose control of the aeroplane in, depending on the manoeuvre he's doing, 30 seconds or a minute," he said.

Detective Chief Inspector Neil Redstone, of Dorset Police, said he had investigated but found no evidence the pilot or aircraft had been interfered with. He also found no evidence of a motive or opportunity to sabotage the helicopter.

He said he had been asked to investigate claims that "Stephen Curtis had approached the National Criminal Intelligence Service offering to become an informant into the activities of Menatep".

Mr Redstone said: "There is no evidence or information to support this claim."

In cross-examination, Mr Redstone said Mr Curtis complied with his obligations under the Proceeds of Crime Act which required that he report the "merest hint" of criminal behaviour in relation to money laundering.

The inquest was due to resume November 2.

First published: November 2, 2005