The Glasgow pub helicopter tragedy which claimed 10 lives happened after both engines on the aircraft failed, an interim report said yesterday.
But the helicopter, which was assisting police operations on the night of November 29, 2013, had 76kg (168lb) of fuel in its main fuel tank and there was no evidence of blockages or leakages, said the special bulletin from the Air Accidents Investigation Branch (AAIB).
It said both engines had “flamed out” before the EC135 helicopter crashed into the Clutha Vaults bar at 10.22pm killing the pilot and two constables on board as well as seven people in the pub.
Examination of the engines showed “no evidence of foreign-object damage or intake or exhaust blockage in either engine”.
No faults were found in the transmission or rotor system, and no evidence of structural failure or in-flight fire, and no evidence of damage caused by bird strike or a foreign object hitting the aircraft in flight.
No CCTV recordings had been obtained which captured the end of the flight and the recorded radio transmissions did not contain any reference by the crew to difficulties with the aircraft.
Due to publish a full report later, the AAIB said its continuing investigation “will seek to determine why a situation arose that led to both the helicopter’s engines flaming out when 76kg remained in the fuel tank group”.
It also still wants to find out “why no emergency radio transmission was received from the pilot and why, following the double engine failure, an autorotative descent and flare recovery (a controlled landing) was not achieved”.
The report also revealed that, three weeks after the crash, the helicopter’s operator Bond Air Services amended its operations manual about fuel reserves while flying.
The pilot who died was David Traill and his passengers were Constables Kirsty Nelis and Tony Collins.
Over 100 people were in the popular city centre bar, near the River Clyde, at the time of the crash.
Those killed in the pub were John McGarrigle, 57, Mark O’Prey, 44, Gary Arthur, 48, Colin Gibson, 33, Robert Jenkins, 61, Samuel McGhee, 56, and Joe Cusker, 59.
There have been calls for a public inquiry into the safety of all commercial flights in the UK in the wake of the incident.
Last month, it emerged the helicopter operator had begun interim payments to the victims. Yesterday’s report said the helicopter had 400kg of fuel on board – enough for 95 minutes of flight – when it left Glasgow City Heliport at 8.45pm to support police. At 10.18pm the pilot requested clearance from air traffic control to re-enter the Glasgow control zone. This was approved and no further radio transmissions were received.
The report says: “Recorded data indicates that, in the latter stages of the flight, the right engine flamed out, and shortly after the left engine flamed out.
“The helicopter descended and struck the roof of the Clutha Vaults bar at a high rate of descent, in an upright attitude. Evidence indicates that the rotor blades and Fenestron tail rotor were not rotating at the moment of impact. The last recoded radar position for the helicopter was at 10.22pm showing it at an altitude of approximately 400ft.”
Pilots’ group Balpa said: “We now know the engines were not running at the time and it appears this was to do with the fuel system. But pilots, like the AAIB, will not be satisfied until this is explored.”