U.S. District Judge John Tunheim pronounced Aaron Cope guilty in a 15-page decision issued after a non-jury trial in Denver that ended last week.
"The court finds the evidence overwhelming that Cope was under the influence of alcohol during the flight," Tunheim wrote in the decision.
"It is extremely fortunate, particularly for the passengers of Flight 7687, that there is no evidence of Cope making poor decisions, affecting safety," the judge stated.
The plane Cope was co-piloting during the December 2009 flight was operated by Shuttle America, a unit of Indianapolis-based Republic Airways Holdings Inc.
A date for Cope's sentencing has not been set. He faces a maximum sentence of 15 years in prison.