The pilot of a police helicopter that crashed into a pub resulting in the deaths of 10 people should have made an emergency call “long before” the final stages of the flight, according to an expert.

Pilot David Traill, two crew members and seven customers in the Clutha bar in Glasgow were killed when the aircraft crashed on to the roof of the building on November 29, 2013.

Being held in a temporary court in Hampden Park, the fatal accident inquiry yesterday heard evidence from two members of the Air Accident Investigation Branch (AAIB).

Marcus Cook, senior inspector at the AAIB, told the inquiry he would have expected an urgency and mayday alarm to have been raised due to low fuel levels but none were made.

He confirmed there had been five low fuel alerts made to the crew during the flight and agreed ignoring such notices would be “downright dangerous”.

Pilots are expected to land within 10 minutes of receiving a low fuel warning and no indication was given to air traffic control there were any issues with the flight.

Mr Cook said: “If he knows he will be landing with less than the final reserve he should make a mayday call.

“If he thinks it’s going to be close to the final reserve he should make a pan call.”

He added: “Speaking to other police helicopter pilots, they all say the one thing you always keep an eye on is how much fuel you have on board.”

Sheriff Principal Craig Turnbull, suggested Mr Traill should have made a mayday when at Bargeddie, to which the inspector replied: “If not before.”

Mr Cook said: “One could suggest that a pan call may have been appropriate earlier on, if you had realised the chance of landing before low fuel reserve. Certainly long before the final stages of the flight.”

Mr Cook also said a pilot who believes the aircraft is going below its final fuel reserve would then make a mayday call. Police helicopter pilots have “acute fuel awareness”, Mr Cook said.

“It’s ingrained in their training from day one.”

He added: “Pilots always have in the back of their mind how much fuel they have, and if it’s not enough, consider diverting.”

Mr Cook also said the pilot would have had three rotor speed warnings, a light coming on and off.

“This indicates there was some input [from the pilot] trying to manage [the situation]”.

Mr Traill was an experienced pilot and had spent nearly 650 hours at the controls of an EC135 helicopter.

As Mr Cook was questioned by Procurator Fiscal Depute Sean Smith QC, a chart of the helicopter’s final journey, which was traced by radar, was shown to the court.

It left Glasgow at 8.45pm in response to reports that someone had been struck by a train at Oatlands, on Glasgow’s south side.

With crew Tony Collins and Kirsty Nelis on board, it then travelled to Dalkeith for a routine surveillance task before carrying out further surveillance in Bothwell, Uddingston and Bargeddie.

At 10.19pm, Mr Traill told air traffic control he was returning to Glasgow City Heliport but at 10.22pm the helicopter plunged into the roof of the Clutha.

Along with the crew on board, seven customers in the Clutha were killed: Gary Arthur, 48; Joe Cusker, 59; Colin Gibson, 33; Robert Jenkins, 61; John McGarrigle, 57; Samuel McGhee, 56; and Mark O’Prey, 44.

The inquiry also heard there are no plans to reopen the AAIB investigation into the crash.

Philip Sleight, deputy chief inspector of air accidents at the AAIB, told the Clutha inquiry there had been new documents presented but none of them were considered new or significant enough.

More than 100 people were at the Clutha Vaults pub when the helicopter, returning to its base on the banks of the River Clyde, crashed through the roof.

An AAIB report published in 2015 found two fuel supply switches were off and the pilot did not follow emergency procedures after a fuel warning in the cockpit.

Phil Sleight, deputy chief inspector of air accidents, told the inquiry there had been new documents presented but none of them were considered new or significant enough.

The purpose of the inquiry is to determine the cause of the deaths, establish whether they could have been prevented and enable the sheriff to make recommendations that could prevent fatalities in similar circumstances.

A total of 57 Crown witnesses are expected to give evidence at the inquiry, down from a previous estimate of 85. Police have taken more than 2,000 statements, while the Crown has around 1,400 productions.

The inquiry continues on Wednesday.