Vijayan Mathan Gopal, who is a Singapore permanent resident, was on the Scoot flight from Cochin, India, on November 2, 2017, reports Channel News Asia.
He was convicted of three counts of outraging the modesty of the 22-year-old air stewardess by holding her right arm and touching her face, cupping her face with his hands, placing his hand on her thigh and touching her buttock.
The victim gave evidence during the trial that she did not know the man before he boarded the plane that day.
He was the last one to board and smelled strongly of alcohol, and his pants were unzipped, she added.
Soon after the plane took off, the victim said that she noticed Vijayan having a dispute with another air stewardess as he did not want to pay after ordering some food and alcohol.
Vijayan in his defence however, denied committing any of the acts against the victim and alleged she had fabricated the incident to suppress the fact that he had complained against the other stewardess for her "poor service".
Vijayan, who will return to court for sentencing on August 28, faces a maximum of two years' jail, fine, caning, or any combination of these punishments for each charge.
( With inputs from IANS )