A GERMAN aeronautical engineer has been called to give evidence today at the Clutha Fatal Accident Inquiry (FAI).

Holger Mendick, a compliance verification engineer for fuel systems with Airbus Helicopters, is being quizzed about technical matters relating to the helicopter that crashed through the roof of the Clutha Vaults Bar in 2013.

Mr Mendick has travelled from Germany to give evidence and has so far been questioned by Procurator Fiscal Depute Sean Smith.

He has been working on the fuel system for the same model of helicopter that crashed on the night of November 29, 2013, since 2000.

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He answered technical questions from the QC about the helicopter's fuel system, saying an EC135 aircraft is twin engine with a dedicated supply tank for each engine.

As the inquiry has previously heard, there was a problem with the helicopter's fuel sensors and Mr Mendick told the court this was "specific" to the EC135.

A droplet of water can become trapped between the two concentric tubes of the sensor, is not able to drain away, and so can cause an "overreading".

Although, the court heard, the sensors are "state-of-the-art", they still contained this problem, which is unique to the EC135.

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A design modification received a patent in 2017 and is now used instead.

A droplet of water, Mr Mendick said, could be enough to short circuit a fuel sensor, leading to a “fuel quantity fail” notification in the cockpit.