A fatal accident inquiry into a police helicopter crash which claimed 10 lives could last at least six months.
Seven customers, the pilot and two crew members were killed when the Police Scotland helicopter crashed on to the roof of the Clutha pub in Glasgow on November 29, 2013.
The first of three preliminary hearings ahead of the full fatal accident inquiry (FAI) took place at Hampden Park stadium in Glasgow on Wednesday.
Family members, Police Scotland, Airbus Helicopters and the Air Accidents Investigation Branch (AAIB) are among those represented at the inquiry.
Sheriff Principal Craig Turnbull, who is overseeing the FAI, said it will be “lengthy and complex.”
The hearing opened with a reading of the names of those who died in the tragedy.
Sheriff Turnbull said: “The purpose of the FAI is to establish the circumstances of the deaths and secondly to consider what steps if any might be taken to prevent further deaths in similar circumstances.
“It is not the purpose of the FAI to establish civil or criminal liability.”
Safran Helicopter Engines, the Civil Aviation Authority, the Scottish Fire and Rescue Service, Scottish Ambulance Service and European Aviation Safety Agency are also represented, as is David Young, the day shift pilot for the helicopter.
Senior Counsel John Smith QC, who is leading the inquiry, said the Crown has commissioned a composite report from two experts - a helicopter pilot and someone who deals with “human factors”.
The Crown is also considering whether it might be possible to commission a 3D interactive model, or make a video simulation model of the helicopter’s last flight available to those involved in the inquiry.
Asked how long the FAI is likely to last, Mr Smith said: “I would say six months,” though he said some parties may view this as “generous or too restrictive”.
The inquiry is due to start in April and will take place at Hampden Park.
Roddy Dunlop QC, representing Airbus Helicopters, said a video simulation of the flight might be of assistance to those involved in the inquiry.
He said: “I’ve shown to the Crown a video simulation which attempts to provide a graphic depiction of the flight and events in the cockpit during the course of the flight that has been put together from data available post-crash from non-volatile memory.
“That could be of assistance to parties in understanding what was happening in the course of the flight. At present it is incomplete and in order to fully understand what is going on it is thought helpful to have a voice-over.
“Once it is in a functional state, it will be made available to your lordship and participants so they can use it.”
More than 100 people were at the Clutha Vaults pub when the helicopter, returning to its base on the banks of the River Clyde, crashed through the roof.
Pub customers John McGarrigle, Mark O’Prey, Gary Arthur, Colin Gibson, Robert Jenkins, Samuel McGhee and Joe Cusker died, while pilot David Traill and crew Pc Tony Collins and Pc Kirsty Nelis were also killed.
An AAIB report published in 2015 found two fuel supply switches were off and the pilot did not follow emergency procedures after a fuel warning in the cockpit.
The Crown Office has previously stated there is insufficient evidence for criminal proceedings.