ON day five of the Clutha Fatal Accident Inquiry (FAI) the court heard more evidence from Robert Vickery, a senior inspector of air accidents with the Air Accident Investigation Branch (AAIB).

The inquiry is examining the circumstances around the fatal helicopter crash in November 2013 into the Clutha Vaults Bar.

This morning's testimony saw Mr Vickery quizzed in depth about sensors in the helicopter's fuel tanks and whether readings from these could have been corrupted by the presence of contaminated water in the fuel tanks.

Due to the size and nature of helicopter engines, the court was told, they require regular cleaning - either a cold or hot compressor wash procedure.

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A cold compressor wash can leave behind traces of water, which may change the readings on the sensors in the fuel tanks.

Mr Vickery told the inquiry crash investigators used a model of the helicopter - an EC135 Articulated Fuel System Test Rig was built by the manufacturers in Germany at the AAIB’s request - to test theories about the effect of water on readings from the sensors.

Following questioning from Procurator Fiscal Depute Sean Smith, Mr Vickery was also questioned by Donald Findlay QC, for the family of victim Robert Jenkins.

Mr Findlay questioned the witness about whether an over-read on the helicopter's fuel gauge, as a result of water contamination, would be "significant or insignificant".

Mr Vickery replied that it could be either.

The QC then asked if the level would be likely to be in the region of a "teaspoon, a cup or a half pint or are you going to simply say you don't know?"

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He added: “Did you see any indication that fuel contamination of any kind had a part to play in the demise of this aircraft?”

Mr Vickery said: “No. There is no indication”.

Pilot David Traill, 51; PC Tony Collins, 43; and PC Kirsty Nelis, 36, lost their lives in the crash along with seven customers who were in the bar on Stockwell Street.

Gary Arthur, 48; Joe Cusker, 59; Colin Gibson, 33; Robert Jenkins, 61; John McGarrigle, 58; Samuel McGhee, 56; and Mark O'Prey, 44 were all killed while a further 31 people were injured.

The inquiry starts again this afternoon with more testimony from Mr Vickery.