The United Airlines pilots arrested at Glasgow Airport accused of being drunk are both veterans of the US military, it has emerged. 

Paul Grebenc and Carlos Roberto Licona, both first officers with United Airlines, were stopped from flying their plane on Saturday morning at Glasgow Airport. 

They were due to fly flight UA162 from Glasgow to Newark, New Jersey, with 141 passengers on board. 

But they were halted at a staff check-in area on suspicion of being over the safe alcohol limit to fly. 

The two pilots are due to appear at Paisley Sheriff Court this afternoon. 

Their arrest comes just weeks after two Canadian pilots were charged with being drunk as they were about to fly a passenger jet from Glasgow to Toronto. 

According to his LinkedIn page, Licona, 45, worked in Military Intelligence for 28 years with the United States Air National Guard, 

Meanwhile Grebenc, 35, describes himself on his Linkedin as an instructor pilot with the United States Air Force and United States Air Force Reserve. 

Grebenc's official first name is Paul but he goes by the nickname Brady on social media. 

The pair are such senior airmen that both have worked as flight instructors teaching others how to fly. 

And, ironically, Grebenc boasts on his LinkedIn of "3200+ hours of accident and Incident-free flying in high-performance fixed-wing aircraft". 

Grebenc is believed to be from Port Collins, Colorado. He now lives in Columbus, Mississippi. 

Licona is believed to be from Texas and studied at the University of Phoenix, Arizona. 

A police spokesman said: "Police Scotland can confirm that two men aged 35 and 45 have been arrested and are presently detained in police custody in connection with alleged offences under the Railways and Transport Safety Act 2003, Section 93." 

Section 93 covers anyone performing an aviation function while over the prescribed limit of alcohol, including acting as a pilot, flight navigator, engineer, member of the cabin crew, or working in maintenance. 

The United Airlines flight was due to take off at 9am, but passengers were forced to wait nine-and-a-half hours before the plane took off with a replacement crew on the flight deck. 

A spokesman for United Airlines said: "The two pilots have been removed from service and their flying duties. 

"We are co-operating with the authorities and will conduct our own investigation as well. The safety of our customers and crew is our highest priority." 

A spokesman for Glasgow Airport said: "We are aware of an incident whereby two crew members were arrested." 

In July, captain Jean-Francois Perreault, 39, and first officer Imran Zafar Syed, 37, were arrested at Glasgow Airport shortly before take-off of an Air Transat flight to Toronto, Canada, and charged with being drunk while trying to fly a plane. 

They were bailed following their second court appearance on condition they surrendered their passports and are due to appear again at a later date. 

The drink-fly limit in Scotland is 20mg of alcohol per 100ml of blood.