THE Crown Office are being urged to open a Fatal Accident Inquiry (FAI) into a 2013 helicopter crash that killed four people off the coast of Sumburgh, Shetland.

Local LibDem MSP Tavish Scott said families had been let down over the time taken by the Crown Office.

He said: “I want the Crown Office to ensure the earliest possible holding of the FAI into the circumstances surrounding the helicopter crash at Sumburgh in 2013. Four years after the tragedy families still wait for closure.

“At the time of the 2013 crash the families were assured that they would not wait for many years for an FAI. Yet it took five years after the 2009 North Sea helicopter crash with 16 fatalities for an FAI to be held.

Police Scotland, at that time, promised families of the 2013 crash that they would not have to endure such a lengthy wait for answers.

“Unfortunately they did.

He added: “A considerable period has now passed following the Sumburgh crash and families are still no nearer knowing what happened and why. Everyone involved would want this FAI to be held without any further delay.”

In initial reports investigators have said pilots had failed to notice a reduction in airspeed.

A report published shortly after the accident by the AAIB said that, as the helicopter approached to within 2.3 nautical miles of the airport, the commander noted that its airspeed had reduced to 80 knots.

He then increased the collective pitch, intending to maintain the speed, but the helicopter’s airspeed reduced to below 80 knots.

This, the report says, went unobserved by the crew.

A short time later, there was an automated audio call of “check height”, which was acknowledged by the commander, and then a comment by the co-pilot to draw the commander’s attention to the airspeed.

At this time, the helicopter’s airspeed was only 35 knots and reducing.

There was then a second automated call of “check height” followed by a “100 feet” automated call.

The report stated: “At some point the commander saw the sea, but he was unable to arrest the helicopter’s descent and it struck the water shortly thereafter.

“The co-pilot, realising that the helicopter was about to enter the water, armed the helicopter’s flotation system.

“After striking the surface the helicopter rapidly inverted, but remained afloat, the flotation equipment having successfully deployed”.

Sarah Darnley, 45, from Elgin, Gary McCrossan, 59, from Inverness, Duncan Munro, 46, from Bishop Auckland, and George Allison, 57, from Winchester, lost their lives in the incident.

Twelve other passengers and two crew were rescued.