THICK cloud and pilot error have been blamed for a helicopter crash which killed three men.

Pilots Wayne Burgess, 32, and Neil Andrew Waterfall, 38, and passenger James Rose, 40, died when the Robinson R44 helicopter in which they were travelling plunged on to Wheelton Moor, near Chorley.

An Air Accident Investigation Branch report released this week said the helicopter had been "intact and serviceable" at the time of the crash, and that the pilot had apparently flown into cloud by accident and then lost control.

A police helicopter pilot who flew to the scene immediately after the crash said conditions in the area around the crash site had been "totally unsuitable for visual flight."

And although Mr Burgess held a helicopter Private Pilot's Licence with Instructor Rating, neither he nor Mr Waterfall -- who was training to fly R44s -- were trained or qualified to fly using only the flight instruments.

After taking off from Blackpool in clear weather, Mr Burgess made contact with staff at Warton radar station, near Preston, just before 5pm to confirm he would be following the M6.

But the helicopter flew over the M6 at Leyland and began following the M61.

The report said this suggested Mr Burgess had not been sure where he was.

"If the commander had been certain of his position at this time it is unlikely that he would have turned to the left, towards high ground, when a turn to the right would have kept him over low lying, relatively flat terrain," the report said.

In the 92 seconds between the helicopter entering cloud, and the fatal crash, several radio transmissions were made between the R44 and Warton radar as Mr Burgess attempted to climb above the cloud layer.

His final transmission was simply: "Helicopter Golf Mike Echo we're in trouble."

The AAIB report concluded: "It is most probable that the helicopter was flown into the cloud inadvertently and the handling pilot became disorientated.

"He was then unable to control the helicopter, which subsequently struck the ground." Wreckage being removed for investigation after February's crash