Graham Leonard, pictured leaving court after admitting endangering an aircraft

A passenger who hijacked a plane's tannoy system while drunk to sing karaoke and then caused an airport to be evacuated could be handed a jail term.

Graham Leonard, who was returning to Scotland after attending a Manchester United football match, grabbed the PA microphone on the private charter flight and burst into song for his fellow football fans after drinking beer and gin on match day.

And after frustrating the cabin crew with his antics during the flight - including throwing a hot towel at one - he then caused part of an airport to be evacuated after deliberately setting off the fire alarm on arrival in Aberdeen.

Sheriff Edward Savage said he was keeping 'all options open' and Mr Kelly to find out what impact a jail sentence would have on his client.

'I'm not entirely satisfied given the very serious nature of these matters that a financial penalty will reflect how serious these matters are,' said Mr Savage.

'I want to make it absolutely clear that I'm keeping all options open.'

Leonard, 46, appeared at Aberdeen Sheriff Court yesterday where he admitted endangering the aircraft and its passengers as well as setting off the airport alarm knowing there was no blaze.

The court heard that Leonard, from Newmacher, in Aberdeenshire, had been part of a group of Scots fans that had chartered an Eastern Airways flight to jet down to watch United's 3-0 league win over Tottenham on March 15 this year.

They had been drinking beer and gin and tonics before leaving Aberdeen Airport, then spent the day meeting former players at a corporate event in a hotel in Manchester.

Fiscal depute Karen Dow said that Leonard was one of three passengers that missed their ride back to the airport after the drunken day out.

When he did eventually board the 9:17pm private flight from Manchester he started causing trouble for the cabin crew.

Leonard was flying on a priavet charter Eastern Airways flight into Aberdeen Airport (file photo)

Ms Dow said: 'During the journey the accused approached the complainer to ask if he could sing a song on the public address system.

'She said no and that was not permitted. The accused went to the PA mic and started singing.

'The complainer approached him and told him to stop and asked him to return to his seat.

'His behaviour persisted. This was frustrating for the complainer as it was part of the communication system used by the captain.'

The court heard that the businessman, who owns a painting and decorating firm in Aberdeen, also repeatedly refused to sit down before throwing a hot hand towel at one of the stewardesses.

Graham Leonard was returning to Scotland after watching Manchester United at Old Trafford, pictured

On arrival at Aberdeen International Airport he was seen 'talking' into the airport's PA system then activating a fire alarm.

Around 40 people had to be evacuated from the area and two units from Scottish Fire and Rescue Service were called out to the false alarm.

Defence agent Gregor Kelly said his client was 'mortified' about his conduct but asked the sheriff to consider a financial penalty.

He said: 'In the sober light of day he is extremely apologetic. The full extent of what he had done did not become clear until the next day when he spoke to others.

After landing at Aberdeen Airport, Leonard set the fire alarm off causing an evacuation

'He is ordinarily a responsible business man.

'He is a regular on this charter plane which goes down to follow the fortunes of Manchester United.

'They had drank a mixture of beer and gin and tonic before embarking on the flight down. There was a special corporate event at hotel in Manchester with ex-players.

'He got carried away. There is no excuse for his behaviour.'

Sentence was deferred for reports.

Leonard was ordained to appear next month.

Speaking after the case called, he said: 'I'm deeply sorry about what happened.