THE four crewmen who lost their lives when a Lynx helicopter plunged into the sea off the Cornish coast died as a result of an accident, an inquest concluded.

The Yeovilton-based helicopter, codenamed Echo Two, was assigned to HMS Portland for a Navy training exercise when it was deployed on a live search-and-rescue mission on 8 December 2004 which turned out to be a false alarm.

Aboard were flight commander Lt David Cole, pilot Lt Robert Dunn, observer Jamie Mitchell and the winchman, Leading Air Engineer Mechanic Richard Darnell.

The jury, sitting at Wells, took eight hours to reach a majority 7-2 verdict after listening to eight days of evidence. A separate verdict was returned for each victim.

Now East Somerset Coroner Tony Williams is to write to Ministry of Defence chiefs to make them aware of his own feelings about the absence of any voice cockpit recorders or data recorders which left a void in the information available to the hearing. "A voice cockpit recorder or data recorder might have shed some light on what happened," he said.

"Having data recorded from such equipment might assist any future investigations that may take place."

He told the families that while he was sorry he could not give them all the answers they wanted, he hoped the proceedings had been helpful and provided a very public arena for the facts.

The crew died from multiple injuries when the Lynx Mk III helicopter plummeted into the sea at 7.03pm. The place of death was specified as 17 miles east of Lizard Point in Cornwall.

Relatives of the crew sat through the two-week inquest listening to details of events leading up to the tragedy and what Lt Cole's father, Mike Cole, called the frustrating three minutes in which no-one was able to determine what happened.

The Lynx, based at RNAS Yeovilton, had embarked on board HMS Portland and had been taking part in anti-submarine exercises with other ships and aircraft over three weeks. During refuelling on the deck of Portland, reports of a man overboard reached them from HMS Montrose, where two ratings had heard screams.

The Lynx was deployed to a search-and-rescue role with a life-raft, flares and a winch. Lt Cole, who had not flown that day, made a last-minute decision to join the mission after it was realised the medical assistant called to take part had no night flight experience.

But the helicopter failed to make a routine check-in call, required every 20 minutes between the helicopter and ship to confirm status and position. Less than a minute after the last radio message was heard from the helicopter, it disappeared from radar screens

No-one saw what happened and the absence of a data recorder and a voice recorder in the cockpit meant that no-one heard what had happened.

The inquest was told it appeared the crew had started crash checks with the engine condition levers in idle position, but no-one would know why they had done so.

A two-and-a-half-year investigation by the Royal Navy Flight Safety and Accident Centre could find no major faults that would have caused the aircraft to crash and a Board of Inquiry was also unable to reach any conclusions.

The families did not wish to comment on the verdicts.