(Seattle, WA)  --  A former Alaska Airlines captain is pleading guilty to flying while drunk.  The U.S. Attorney's Office says David Hans Arnston is pleading guilty as part of a plea bargain.  The Attorney's Office says Arnston was given a breathalyzer test in June of 2014 after being chosen for a random screening and the results showed an alcohol level higher than what's allowed for airline pilots.  Arnston had just completed a flight from San Diego to Portland followed by a Portland to Orange County flight when he was tested.