ENGINEERS at Glasgow Heliport had replacement parts to fix a fault on the doomed Clutha helicopter but never carried out the work, an inquiry has heard.

Pilot Craig Trott spotted issues with the fuel readings on the Police Scotland helicopter G-SPAO on September 30, 2013, just two months before the fatal crash.

Mr Trott emailed James Remfry, then a base maintenance coordinator at Bond, to flag up the issue and was told two new sensors would be sent to Glasgow.

Giving evidence to a fatal accident inquiry, Mr Remfry told the court he decided to send replacement parts for the helicopter.

He said: "My decision at that time was that there may not be a problem with the system but it's better to be safe and sure."

Mr Trott's email from September 2013, shown to the court, showed that G-SPAO had been filled with 400kg of fuel - 310kg in the main tank - but after two hours this had dropped to 295kg.

But when the engine was started and the helicopter took off, the fuel level rose to 320kg.

Mr Trott said there was no fuel leak or any other way to explain the discrepancy.

On October 1, 2103, Mr Remfry, now maintenance manager for Babcock, which took over Bond, replied to say he had taken up the issue with the avionics manager, Martin Forster, and two new fuel sensors would be sent to Glasgow.

In the meantime, Mr Trott said he would add 30kg of fuel to his minimum indications and leave a briefing for the next pilot, Steve Kitchen.

Mr Remfry, 58, told Mr Trott he could continue flying the aircraft but no record of the main tank fuel sensors was made in the technical logs.

The 58-year-old, being examined by lawyer Gordon Lamont, for the Crown, said he "would expect that work to be carried out."

The inquiry, in a temporary court at Hampden Park, was also shown the pilot's log book dated October 2, 2013 with the note "To Steve Kitchen. AO 'S' 400kg - plus or minus 30!"

The pages for September 30 and October 1 were left blank.

Mr Remfry was asked why the fuel sensor issue would not have been flagged up on September 30 and he said he could not explain it.

On the night of November 29, 2013, G-SPAO crashed through the roof of the Clutha Vaults bar in Glasgow, killing the pilot, David Traill, and two Police Scotland air observers.

Another seven customers inside the pub were also killed.

Mr Remfry told the court that fuel sensor issues were not uncommon. He said: "We had a number of reports from the log were pilots would, on fuelling up the aircraft, would report that the amount of fuel gone in the aircraft against the amount of fuel on the display would show a discrepancy."

Following an incident with air ambulance G-NWEM, based at Manchester Heliport, investigations found that water contamination could affect the fuel system and cause over-readings, the court has previously heard.

Babcock took various steps to prevent this from happening.

Mr Remfry said: "It is very rare for us now to have to change a fuel probe when the fault is caused by water.

"Very few fuel probes are failing as a result of water ingress."

The court was also shown records relating to helicopters G-OMAA, which logged a fuel tank sensor issue on August 11, 2014, and G-HWAA, which showed water and compressor wash in the fuel system on October 10, 2014.

On October 31, 2014, G-HWAA - an EC 135 helicopter of the same type as the Clutha helicopter - also recorded a fuel quantity fail.

A pilot's report dated February 11, 2018, detailed how it had taken an hour and 20 minutes to obtain a clear fuel sample from the aircraft and necessitated draining 35 litres of fuel before a clear sample was taken.

The aircraft was then taken "offline" - or out of service.

Lawyer David Adams, representing Mr Traill's fiancee Lucy Thomas, asked if Remfry was "surprised" at this "after all the steps [Bond] had taken to ensure water was not entering the EC 135?"

Mr Remfrey said that the tablets used for the fuel tests are very sensitive and added: "So I'm not surprised" although 35kg "is more than I would usually expect" to have to be drained before a clear sample would be found.

The inquiry in front of Sheriff Principal Craig Turnbull continues on Friday.