(Portland, OR)  --  Authorities say a former Alaska Airlines pilot was under the influence of alcohol when he flew out of Portland International Airport in 2014.  Sixty-year-old David Hans Arnston of Newport Beach, California, was arrested on federal charges earlier this week.  Officials say the charges against Arnston stemmed from a random drug test on June 20, 2014, after he piloted two Alaska Airlines flights.  The airline says Arnston was removed from duty following the drug test results.  He retired soon afterward.