A chilling tableau of helicopter pilot David Traill's desperate struggle to avert catastrophe in the moments before crashing into the roof of the Clutha bar has unfolded as lawyers picked over an air accident report last week at Hampden.
Shortly after his Eurocopter EC135 had entered airspace over Glasgow's east end, the main engine flared out, followed by a similar failure of the second engine just 32 seconds later. Within moments, Captain Traill had made repeated attempts at autorotation – an emergency manoeuvre which involves seeking to control the craft by using the upward flow of air to the rotor. He also tried 'flaring', by which airspeed is reduced in order to achieve a cushioned landing as the helicopter plunged its last 500 feet towards the ground. Neither manoeuvre succeeded.
Investigators estimated that Captain Traill had just a single second to decide what to do when the engines failed. The harrowing details of those final moments were calculated during the preparation of a 2015 report by the Air Accident Investigation Bureau (AAIB), based at Farnborough. Mr Marcus Cook, the Bureau's senior inspector of air accidents, told the inquiry that he and his colleagues had been unable to identify a reason for Captain Traill's apparent failure to respond to earlier fuel tank warnings during what has been described as a routine flight.
The Police Scotland helicopter, registration G-SPAO, left its Glasgow heliport base at 8.44pm on a routine mission on Friday 29 November 2013. The pilot and crew of two experienced police observers, Constables Kirsty Nelis and Tony Collins, spent 33 minutes over railway lines at Oatlands, Glasgow, attempting to locate a body after reports that a man had been struck by a train. No person was found, and the crew left to carry out surveillance work over Dalkeith, Midlothian.
The AAIB report, which tracked each stage of the journey, including communications with Edinburgh and Glasgow air traffic control centres, finds no fault with the journey during that trip to Dalkeith. It is on return, somewhere between Shotts and Bothwell, that the first signs of trouble appear to have emerged.
Investigators estimated that the first low-fuel warning occurred around the time the EC135 arrived at Bothwell, where the crew carried out what was described as non-urgent duties. Mr Cook told the inquiry that, as a qualified pilot himself, he would have taken the alert as a signal to return to base in Glasgow forthwith. Although the aircraft appears to have had enough fuel, the warning should have triggered a decision to err on the safe side and head for base immediately, he said.
The crew carried out a brief surveillance fly-over at Bothwell before moving on to nearby Uddingston, and then to a third location, Bargeddie. It was only then that Captain Traill turned for Glasgow and set off towards the heliport, which sits little more than a mile to the west of the Clutha Bar on Clydeside.
Captain Traill, aged 51, was an extremely experienced helicopter pilot with 5,592 hours total flying time. Formerly with the Royal Air Force, he had flown Chinook aircraft in active service in Bosnia, Northern Ireland, Afghanistan and Iraq. He was a certified instructor, training other pilots in Chinooks and also the Eurocopter Squirrel. He had flown the Police Scotland aircraft for more than five years prior to the 2013 tragedy, originally when it had been operated by the Strathclyde force before the national police merger.
There was no communication from the pilot to indicate that he was having trouble. Neither were there any warning calls from the police observers, both of whom had separate communications links to their own control room. The report found that, while the main tank contained 76kg of fuel – probably enough to land safely back at base – the two supply tanks which it fed were virtually empty. Supply pumps to those tanks had been closed. The AAIB report offered no conclusion as to why this might have been.
The report has not disclosed the purpose of the 'detour' to the Lanarkshire vicinity. Asked by Donald Findlay QC, acting on behalf of the partner of Clutha victim Robert Jenkins, Mr Cook said that he would have been watching fuel levels very closely whilst heading there. As a general rule, the helicopter needed 200kg per hour of travel, plus enough fuel to land. G-SPAO had taken off with 400kg in its tanks, and was in the air for a total of approximately one hour and 45 minutes when it crashed.
Experts estimated that the aircraft was carrying 122kg of fuel when it reached Bothwell, and this had reduced to 100kg at Bargeddie. Little more than a few minutes was spent at each location. Glasgow air traffic clearance was requested and granted without mention of any incident. Mr Cook said he would have expected the pilot to have made a 'Pan' or 'urgent' call on receipt of the fuel warnings, giving him priority for landing, but no such request was made.
The warnings would have been seen and heard by the police observers. In addition a distinctive 'gong' sound would have been played in their headsets.
All three were dead by the time specialist fire and rescue officers reached the cabin of the aircraft atop the Clutha's roof after the crash. Constable Nelis was in the front seat beside the pilot, and Constable Collins was in a rear seat. All three had suffered traumatic head, neck and chest injuries on impact.
Constables Nelis and Collins had 13 and 18 years' police service respectively. Toxicology tests on all three on board the aircraft were negative. The victims of the crash included bar customers Gary Arthur, 48; Joe Cusker, 59; Colin Gibson, 33; Robert Jenkins, 61; John McGarrigle, 57; Samuel McGhee, 56; and Mark O'Prey, 44. The helicopter crew included pilot David Traill, 51, and police officers PC Tony Collins, 43, and PC Kirsty Nelis, 36.
Details of the recovery of the bodies, and subsequent post-mortems, were given at the inquiry last week. All died mainly of crush injuries, especially to the head and chest. Mark O'Prey was trapped from the legs when discovered, and attempts to free him were hampered by the weight of debris. He succumbed soon after initial emergency treatment on location. Joe Cusker died of multiple organ failure resulting from his injuries in hospital 13 days after the incident.
The inquiry continues, with further evidence from AAIB witnesses this week.
Maurice Smith will be attending and reporting on the Clutha FAI each week in SR