Police helicopter crash inquiry underway
An UK Air Accident Investigation Board (AAIB) inquiry into the fatal crash of an EC135 police helicopter in Scotland in 2013 is currently underway
An UK Air Accident Investigation Board (AAIB) inquiry into the fatal crash of an EC135 police helicopter in Scotland in 2013 is currently underway (17 April), with the AAIB explaining that as the aircraft did not carry a flight recorder, little data is available about what happened immediately before the accident occurred. Leading the inquiry is Sheriff Principal Craig Turnbull, who said that the aim is not to result in criminal proceedings, but to learn lessons.
Pilot of the aircraft David Traill was killed in the crash, along with PC Tony Collins and PC Kirsty Nelis, and seven customers who were in the bar into which the aircraft crash landed; 31 people were injured. Peter Wivell, a senior inspector with the AAIB, confirmed findings of a report that has previously been published that looked into the cause of the crash, in which it was noted: “The transfer of fuel from the main tank to the supply tank stopped while the helicopter was returning to Glasgow from Dalkeith, leaving only the fuel in the supply tank available to the engines.” Wivell said the lack of flight recorder on the aircraft made it difficult to complete a full investigation into the cause of the accident.
The original AAIB accident report from 2015 stated:
“The helicopter departed Glasgow City Heliport (GCH) at 2044 hrs on 29 November 2013, in support of Police Scotland operations. On board were the pilot and two Police Observers. After their initial task, south of Glasgow City Centre, they completed four more tasks; one in Dalkeith, Midlothian, and three others to the east of Glasgow, before routing back towards the heliport. When the helicopter was about 2.7 nm from GCH, the right engine flamed out. Shortly afterwards, the left engine also flamed out. An autorotation, flare recovery and landing were not achieved and the helicopter descended at a high rate onto the roof of the Clutha Vaults Bar, which collapsed. The three occupants in the helicopter and seven people in the bar were fatally injured. Eleven others in the bar were seriously injured. Fuel in the helicopter’s main fuel tank is pumped by two transfer pumps into a supply tank, which is divided into two cells. Each cell of the supply tank feeds its respective engine.
During subsequent examination of the helicopter, 76 kg of fuel was recovered from the main fuel tank. However, the supply tank was found to have been empty at the time of impact. It was deduced from wreckage examination and testing that both fuel transfer pumps in the main tank had been selected off for a sustained period before the accident, leaving the fuel in the main tank, unusable. The low fuel 1 and low fuel 2 warning captions, and their associated audio attention-getters, had been triggered and acknowledged, after which, the flight had continued beyond the 10-minute period specified in the Pilot’s Checklist Emergency and Malfunction Procedures.
The helicopter was not required to have, and was not fitted with, flight recorders. However, data and recordings were recovered from non-volatile memory (NVM) in systems onboard the helicopter, and radar, radio, police equipment and CCTV recordings were also examined. During the investigation, the EC135’s fuel sensing, gauging and indication system, and the Caution Advisory Display and Warning Unit were thoroughly examined. This included tests resulting from an incident involving another EC135 T2+.
Despite extensive analysis of the limited evidence available, it was not possible to determine why both fuel transfer pumps in the main tank remained off during the latter part of the flight, why the helicopter did not land within the time specified following activation of the low fuel warnings and why a MAYDAY call was not received from the pilot. Also, it was not possible to establish why a more successful autorotation and landing was not achieved, albeit in particularly demanding circumstances.”
During the current inquiry, AAIB investigators have reported that they have nothing ‘new or significant’ to add to the original investigation, and that therefore it would not open a second investigation into the accident.