Drinking one’s own alcohol onboard is not illegal,
In Canada it is:
Alcohol or Drugs — Passengers
- 602.04 (1) In this section, intoxicating liquor means a beverage that contains more than 2.5 per cent proof spirits.
- (2) No person shall consume on board an aircraft an intoxicating liquor unless the intoxicating liquor
- (a) has been served to that person by the operator of the aircraft.......
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