Final answer:
The legal drinking age on Air Transat flights aligns with the legal drinking age of the destination. It varies and can be either 18, 19, or 21 years old. To confirm, passengers should check with Air Transat's policy.
Step-by-step explanation:
The legal age to drink on Air Transat flights is determined by the destination's legal drinking age. If the flight is heading to a destination where the legal drinking age is 18, then the minimum age for drinking on the flight would be 18 years old. Conversely, if the destination has a higher legal drinking age, such as 21, then that would apply instead. Additionally, airline policies can also influence the minimum drinking age, so it is best to check with Air Transat directly for their specific policy.