A HUMAN behaviour expert has said the Clutha crash pilot could have ignored protocol in the belief he was keeping his crew safe.

Professor Polly Dalton produced a report looking at the potential motivations of Captain David Traill on the night of the helicopter crash.

A fatal accident inquiry has previously heard that Mr Traill was a highly skilled and experienced pilot.

Yet during the final flight of helicopter G-SPAO, the court has heard, fuel pump switches were in the "off" position when they should have been on.

The helicopter gave out five low fuel warnings, which meant the pilot should have landed the aircraft within 10 minutes, yet Mr Traill continued to fly.

Prof Dalton, a psychologist specialising in human behaviour at Royal Holloway, University of London, was asked to give a view on why a pilot might not follow set procedures.

Helicopters prior to the Clutha crash, on November 29, 2013, were not fitted with black box recording equipment and so there is no record of what was shared by the crew of the helicopter, which included Police Scotland air observers PC Tony Collins and PC Kirsty Nelis.

However, the inquiry has previously heard from the air traffic controller who received the final communication from Mr Traill, saying the helicopter was returning to base.

READ MORE:

Clash into reports on Clutha crash

The court heard there was no background noise from the radio transmission that would cause alarm and that Mr Traill sounded calm.

The inquiry has previously heard that Ms Nelis was a competent air observer and that Mr Collins was one of the best air observers in the unit.

The police officers are trained to work with the pilot as a team and to call out any warnings they see on the aircraft's caution advisory display (CAD).

Questioned by Procurator Fiscal Depute Sean Smith, Prof Dalton said Mr Traill’s actions would “appear to constitute a deliberate violation of procedure” but went on to explain that there are “routine violations” and “exceptional violations”.

Given the witness statements describing Mr Traill as a competent and experienced pilot, to not follow procedure would be an exceptional violation, the court was told.

Prof Dalton was also asked why she thought an experienced pilot like Captain Traill would not have realised the fuel pump switches were off.

She said: "These kind of mistakes are possible. They are part of being human, I would say.

"So just being an experienced operator and skilled pilot doesn’t mean you are immune from making errors."

In response to the Clutha crash, switches are now fitted with tactile covers to help pilots distinguish between switches.

Prof Dalton also told the court of the "cry wolf effect": if warnings go off repeatedly when there is no emergency, people's likelihood of taking them seriously is lessened.

Shelagh McCall, QC, counsel for Lucy Thomas, put it to Prof Dalton that the police air observers must also have been satisfied to continue, despite the alarms, given their training and reputations.

The academic agreed.

READ MORE:

Clutha-type helicopter gave false readings

The court also heard that just seven minutes before the crash Mr Collins made his final note about the team’s mission.

Mr Collins had made notes of the aircraft's manoeuvres at 10.05pm, 10.10pm and then, finally, at 10.15pm.

The helicopter crashed into the roof of the Clutha at 10.22pm.

On the night of its final flight, Mr Traill, 51, and his crew flew to East Lothian before travelling to Uddingston, Bothwell and Bargeddie.

Gary Arthur, 48, Joe Cusker, 59,Colin Gibson, 33, Robert Jenkins, 61, John McGarrigle, 58, Samuel McGhee, 56 and Mark O’Prey, 44, were killed in the bar.

The inquiry is now adjourned until August 5.