Police said the 24-year-old man travelling on a WestJet flight from Toronto became agitated during the plane's descent.
"Several passengers stepped in and subdued the man and held him until police attended and arrested him," said RCMP Sgt. Mike Lidstone. "They ended up taking him to the QE II hospital for psychiatric assessment."
The man is originally from Dartmouth, N.S., but now lives in Los Angeles.
Lidstone said the airplane landed without incident.