Judge Timothy Gabriel said he didn't believe Alicia Elizabeth Lander's testimony explaining her actions on the flight from Toronto to Halifax on Jan. 24, 2014.
Gabriel said Lander could clearly recall that she had 14 shots of whisky at the Toronto airport and on the flight, but did not recall pulling her underwear down on the plane, speaking to flight attendants or being taken away by police in Halifax.
"Her actions appear to have been deliberate," Gabriel told the court. "There was no indication that she was in any type of diminished capacity. She was intoxicated.
"She simply chose to behave in a disgraceful manner."
Gabriel also found her guilty of assaulting a police officer, committing an act of mischief and causing a disturbance that damaged property at Halifax Stanfield International Airport.
Lander, 26, who pleaded not guilty to the offences, testified that she began drinking at the airport on her way back from Edmonton because she was depressed.
A man next to her began buying her drinks and stopped only when they had to board the flight to Halifax, Lander said, adding she drank up to 10 shots in about 20 minutes, followed by more on the flight.
"I feel ashamed it happened. I would never, ever do something in that kind of manner," she testified. "It's not me. It's not me to assault anyone."
John Dunn, who was service director for Air Canada Flight 610, testified earlier that Lander had asked if she could change seats to sit with her friend after boarding the plane in Toronto.
About an hour into the flight, Dunn said a passenger told him the people sitting in seats 14A and 14B were about to join the "Mile High Club."
He testified that he found Lander and the man with a small jacket over their laps, but he could tell what they were doing.
Dunn said he could see that Lander's underwear were down around her ankles and he asked her to get dressed, although she initially denied being undressed.
"The parties were engaged in actions that were described by Mr. Dunn ... as mutual masturbation," Gabriel said.
Lander was asked to go back to the seat she was originally assigned and slept for the remainder of the flight, Dunn said.
Gabriel said Lander became combative and called Dunn a liar when he was telling police what happened onboard.
RCMP Const. Mac Routliffe testified that Lander was disruptive and screaming profanities after meeting officers at the arrivals gate. He also said Lander kicked him twice.
She was placed in an interview room and Routliffe testified that he and another officer had to hold the door shut to contain her. He said she kicked holes in the walls of the room.
Jason George Chase, 40, was also charged with committing an indecent act in connection with the same incident and had originally pleaded not guilty, but changed his plea to guilty in January.
Crown attorney Cheryl Byard said she will likely not seek jail time when they return to court in July for sentencing.
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